The famous "10 ℃ law" indicates that the reliability of electronic devices is closely related to the temperature, i.e., the reliability can be reduced by 50% for every 10 ℃ increase in temperature when the temperature of electronic devices exceeds 80 ℃. It is thus extremely important to discharge the waste heat of electronic devices in time to achieve an efficient device cooling. Heat transfer methods include heat conduction, heat convection and heat radiation. Conventional air-cooled and liquid-cooled achieve cooling via heat convection and heat conduction. In addition, the cooling technologies also include magnetic cooling (i.e., magneto-thermal effect), phase change cooling (i.e., phase change heat storage) and thermoelectric cooling (i.e., the Peltier effect). With the high integration and miniaturization of electronic devices, especially flexible electronic devices limited by size and deformation, conventional cooling technologies are no longer applicable. The newly flexible radiative cooling films with zero power consumption become potential candidates for cooling electronic devices and are expected to promote the development of the national dual-carbon cause, which can emit heat to outer space through thermal radiation and reject solar irradiance. However, it is extremely difficult to combine outstanding radiative cooling performance with excellent thermostability limited by materials and preparation process. In this paper, Al₂O₃-doped colorless polyimide hybrid films were prepared by a sol-gel method. The infrared radiation enhanced by Al₂O₃ phonon-enhanced resonance and the higher thermostability because of the interaction of Al₂O₃ nanoparticles with the molecular chains were analyzed.

TFMB (0.365 7 g) was mixed with DMAc (6 mL) under electromagnetic stirring at 0 ℃. Al(OH)₃ sol at different contents (i.e., 0%, 5%, 10%, 15%, and 20%, in mass fraction) was added to the solution above. An accurately weighed 6FDA (0.503 6 g) was sequentially added to a trident flask in batches for 1 h, and then stirred continuously for 30 min. Subsequently, the mixture was stirred at room temperature for 4 h. The obtained precursor poly (amido acid) (PAA) solution was rested for 12 h.

The PAA solution was coated onto a dry clean glass substrate by a spin-coating method and dried in a vacuum tube furnace at 80 ℃ for 1 h and then at 50 ℃ for 12 h to ensure that the solvent was removed completely. The sample was heated in a vacuum tube furnace in respective heating steps (i.e., at 110 ℃ for 30 min; at 140 ℃ for 30 min; at 170 ℃ for 30 min; at 200 ℃ for 30 min; at 220 ℃ for 30 min; and at 280 ℃ for 60 min).

The obtained Al₂O₃-doped colorless polyimide (CPI) films were ultrasonically cleaned with absolute alcohol and deionized water for 30 min. The films were blown dry and put into a vacuum chamber. A 300 nm thick silver (Ag) film was deposited on the backside of the Al₂O₃-doped CPI film via direct current sputtering at 6×10^-4 Pa. The argon flow rate, sputtering pressure and Ag target power were 50 cm³/min, 0.5 Pa and 100 W, respectively.

The mid-infrared emissivities (5-20 µm) of Al₂O₃-doped CPI/Ag hybrid films increase with increasing Al₂O₃ content. The mid-infrared emissivities are measured as ε(0%)=87.54%, ε(5%)=92.15%, ε(10%)=92.23%, ε(15%)=93.25%, and ε(20%)=94.51%, respectively. The solar reflectivities (0.4-2.5 µm) decrease with increasing Al₂O₃ content. The solar reflectivities (R) are measured as R(0%)=94.81%, R(5%)=91.12%, R(10%)=89.31%, R(15%)=88.36%, and R(20%)=83.87%, respectively. This is because the scattering effect of the hybrid films increases with increasing Al₂O₃ content. The visible reflectivities (0.40-0.75 µm) firstly increase and then decrease with increasing Al₂O₃ content. The 5% Al₂O₃-doped CPI/Ag hybrid film has the maximum reflectance in the visible band, which can effectively improve the net cooling power of the hybrid film. Meanwhile, the intense interaction of Al₂O₃ nanoparticles with the molecular chains can effectively enhance the thermostability of the hybrid films. Compared with 0%Al₂O₃-doped CPI film, the glass-transition temperature (T_g) of 5% Al₂O₃-doped CPI film is 328 ℃, which is increased by 22 ℃.

The Al₂O₃-doped CPI hybrid film was prepared by a sol-gel method. The infrared radiation increased due to the phonon-enhanced resonance, and the thermostability improved due to the interaction between Al₂O₃ nanoparticles and molecular chains. The 5% Al₂O₃-doped CPI/Ag hybrid film had a high solar (0.4-2.5 µm) reflectivity (i.e., 91.12%) and a mid-infrared (5-20 µm) emissivity (i.e., 92.15%). The maximum cooling capability of 7.7 ℃ and 11.1 ℃ that were lower than that of bare aluminum device was achieved under sunlight. The Al₂O₃-doped CPI hybrid film exhibited superior thermostability (i.e., T_g~328 ℃), and thermal decomposition temperature (i.e., T_5%~554 ℃). The results indicated an effective strategy to realize efficient radiative cooling for electronic devices and appendages in spacecraft.

Lithium metal batteries (LMBs) are regarded as candidates for next-generation batteries due to their low electrochemical potential (i.e., -3.040 V vs. standard hydrogen electrode) and high theoretical specific capacity (i.e., 3 860 mA·h·g^-1). Lithium (Li) metal anode is susceptible to side reactions with organic electrolytes, leading to the uneven formation of the solid electrolyte interphase (SEI). The non-uniformity and fragility of the SEI can aggravate the growth of Li dendrites and excessive electrolyte consumption, ultimately resulting in a rapid attenuation of capacity and safety risks. These issues severely hinder the commercialization of LMBs. The development of an artificial SEI is crucial for protecting Li metal anode, suppressing Li dendrite growth, and accommodating volume changes during cycling. This advancement is essential for improving the stability and cycling life of LMBs.

In this paper, we synthesized an artificial elastic polymer SEI (EP-SEI) constructed on the surface of Li metal anode by an in-situ UV-curing method. The main composition of EP-SEI was poly (ethyleneglycol) diacrylate-co-vinylene carbonate (PEGDA-CO-VC) cross-linking polymer.

For the synthesis of an artificial elastic polymer SEI (EP-SEI) constructed on the surface of Li metal anode by an in-situ UV-curing method, polyethylene glycol diacrylate (PEGDA) and vinylene carbonate (VC) were mixed in a mass ratio of 4∶1 (i.e., 80 mg and 20 mg) under stirring. Afterwards, 2 mL of dimethoxyethane (DME) was added for dissolution. Subsequently, the mixture was dripped onto Li metal foils, followed by polymerization under a mercury lamp after the addition of 2-hydroxy-2-methylpropiophenone (HMPP). This method utilized UV light to rapidly excite the unsaturated bonds of polymer monomers, thereby shortening the polymerization reaction time and enhancing the preparation efficiency of the artificial SEI. This method was simple to operate, conducive to batch production, and aids in advancing the commercialization of LMB. The LMBs were assembled with LiFePO₄ (LFP) or LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) as a cathode material, Li metal foil as an anode, polypropylene (PP) as a separator, and 1 M LiPF₆ EC/DEC as an electrolyte. The batteries were assembled in a glove box filled with argon to ensure a moisture-free and oxygen-free environment during the process.

An artificial EP-SEI with PEGDA-co-VC was prepared on the surface of Li metal by an in-situ UV-curing polymerization method. The thickness of EP-SEI is 1.6 μm. The EP-SEI exhibits an uniform and dense morphology and tightly covers the surface of Li metal. In the results of electrochemical test, Li symmetric (Li || Li) cells assembled with EP-SEI protected Li exhibit highly reversible electrochemical behavior and faster charge transfer rates. The Li || Li cells with EP-SEI Li maintain stable cycling at a current density of 1 mA·cm^-2 and a capacity density of 1 mA·h·cm^-2 for over 300 h. And the impedance values of Li || Li cells with EP-SEI Li continuously decrease during the cycle, and eventually stabilize at 15 Ω. This indicates that EP-SEI exhibits a high stability during prolonged electrochemical reactions and a high lithium ion conductivity. In the results of Li ||Cu cells test, the low nucleation overpotential (μ_nuc) and plateau potential (μ_pla) indicate a reduction in the nucleation energy barrier for Li deposition. It is confirmed that EP-SEI can promote the uniform deposition of Li⁺ on the surface of Li metal. After cycling of Li ||Cu cell with EP-SEI Cu, the thickness of Li⁺ deposition approaches the theoretical thickness. The surface of EP-SEI Cu remains smooth and flat without the growth of Li dendrites. In the results of full cell test, the LFP || Li batteries with EP-SEI Li exhibit a discharge specific capacity of 164.1 mA·h·g^-1 and a capacity retention rate of 72% after 500 cycles with a coulombic efficiency of 98.5% at 0.5 C rate. The NCM811 || Li batteries with EP-SEI Li maintain a discharge specific capacity of 100 mA·h·g^-1 after 500 cycles. This demonstrates that EP-SEI effectively reduces electrolyte consumption and improves coulomb efficiency, cycle stability and safety of LMBs.

In this study, an elastic polymer artificial solid electrolyte interphase membrane (EP-SEI) was constructed on the Li metal anode by an in-situ UV-curing polymerization method. This EP-SEI exhibited excellent uniformity, stability and elasticity, promoting the uniform deposition of Li⁺ during cycling. These properties indicated that EP-SEI could inhibit Li dendrite formation, buffer the volume changes of the Li metal anode, and reduce electrolyte consumption. The LFP || Li and NCM811 || Li batteries assembled with EP-SEI-protected Li metal anodes achieved discharge specific capacities of 164.1 mA·h·g^-1 and 187.1 mA·h·g^-1 at 0.5 C rate, respectively. The LMBs maintained stable cycling for 500 cycles. The EP-SEI could effectively protect the Li metal anode, improve the coulombic efficiency and extend the cycling life of LMB. The EP-SEI protected Li metal anode provided the possibilities for the commercialization of LMBs.

Supercapacitors are widely used due to their fast charging and discharging processes, high power density (i.e., kW·kg^-1), fast charging and discharging (i.e., minutes or even seconds), and long cycle term (i.e., up to 100 000 cycles theoretically). The electrode materials determine the electrochemical energy storage performance of the supercapacitor. It is thus important for the development of high-performance electrode materials to improve the performances of the supercapacitor. Many electrode materials are explored for supercapacitors, such as transition metal oxides, transition metal hydroxides and transition metal sulfide. The electrode materials show the promising practical applications. To further optimize the electrochemical performances of the electrode materials, the supercapacitors with the composites are developed as electrode materials. Among the composites, transition metal sulfide-based electrode materials have attracted much attention because of their outstanding performances for energy performances of supercapacitors. In this paper, Ni₃Se₂/Ni₃S₂ nanocomposites were synthesized on nickel foam by a solvothermal and selenization method, and their structures and electrochemical energy storage performances were systematically investigated.

4.4 g Na₂S·9H₂O was dissolved in 40 mL methanol under stirring vigorously for 30 min. The solution was moved to 2 Teflon-lined stainless steel autoclaves, equally, and two cleaned Ni foams were immersed in the solution, respectively, then the autoclaves were kept in an oven 140 ℃ for 16 h. After the reaction, Ni₃S₂ nanorods on Ni foam (Ni₃S₂/Ni) were obtained.

0.01　g Se powder was dissolved in 6 mL hydrazine hydrate (resolution A). 9 mL DI-water and 15 mL ethanol were added into resolution A, obtaining resolution B. Resolution B was transfered to 2 autoclaves. Two Ni₃S₂/Ni samples were put into two autoclaves with resolution B. The autoclaves were kept in an oven at 140 ℃ for 10 h. The samples were prepared at different growth temperatures and time.

The crystal structure and morphology of the samples were determined by X-ray diffraction (XRD, Bruker-D8, λ=0.154 05 nm), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The chemical elements and valence bond states were analyzed by X-ray photoelectron spectroscopy (XPS, Al Kα) and X-ray energy spectrometry (EDS). The electrochemical properties were examined on an electrochemcial system with Ni₃Se₂/Ni₃S₂ nanocomposites as working electrodes at room temperature.

The SEM images of Ni₃Se₂/Ni₃S₂ nanocomposites show that Ni₃Se₂ nanoparticles cover Ni₃S₂ nanorods. Besides, some Ni₃Se₂ clusters are on the top of Ni₃S₂ nanorods. Moreover, the HRTEM images of Ni₃Se₂/Ni₃S₂ nanocomposites reveal the interfaces between Ni₃Se₂ and Ni₃S₂.

Under the optimized growth conditions, the specific capacitance of Ni₃Se₂/Ni₃S₂ nanocomposites can reach 2 482.00 mF·cm^-2 (@1 mA·cm^-2), and the specific capacitance retention rate is still 68.45% after 2 000 charge-discharge cycles at 10 mA·cm^-2, and the coulombic efficiency is 97.20%-99.28%. The assembled liquid (6 mol/L KOH) Ni₃Se₂/Ni₃S₂//AC asymmetric supercapacitor demonstrates a specific capacitance of up to 768.75 mF·cm^-2 (@2.5 mA·cm^-2). The assembled Ni₃Se₂/Ni₃S₂//AC all solid-state supercapacitor (ASS) has a specific capacitance of 983.57 mF·cm^-2 (@7.5 mA·cm^-2). The outstanding electrochemical performances of Ni₃Se₂/Ni₃S₂ nanocomposites can be since: 1) Ni₃Se₂/Ni₃S₂ nanocomposites are fabricated on Ni foam, directly, reducing the contact resistance due to the good conductivity of Ni foam; 2) Ni₃Se₂/Ni₃S₂ nanocomposites on Ni foam have a three-dimensional structure, exhibiting the large specific surface area for the electrochemical reactions; and 3) the synergies of Ni₃Se₂ and Ni₃S₂ can improve the electrochemical performances. In addition, the integrated circuits with Ni₃Se₂/Ni₃S₂//AC solid-state capacitor are also analyzed. The series Ni₃Se₂/Ni₃S₂//AC ASSs demonstrate a typical increase in the operating voltage window, and the parallel ones show the improvement of the specific capacitance, indicating the promising practical applications for energy storage of Ni₃Se₂/Ni₃S₂ nanocomposites.

Ni₃Se₂/Ni₃S₂ nanocomposites were prepared as electrode materials for supercapacitors and their the electrochemical performances were investigated. As the electrode material, Ni₃Se₂/Ni₃S₂ nanocomposites showed the outstanding properties for energy storage. At 1 mA·cm^-2, the constructed supercapacitor in 6 mol/L KOH solution exhibited the specific capacitance of 2 482 mF·cm^-2. the ASS devices were also constructed with Ni₃Se₂/Ni₃S₂ nanocomposites, showing good electrochemical performances for energy storage. Furthermore, the ASS devices with Ni₃Se₂/Ni₃S₂ nanocomposites as electrode material showed the typical integrated features in series and parallel circuits. Singe ASS device demonstrated 0-1.4 V working voltage window, and two series devices could work well in 0-2.8 V, while the specific capacitance presented the obvious improvement for two parallel ASS devices. Therefore, the study could demonstrate a potential application of Ni₃Se₂/Ni₃S₂ nanocomposites, and provide an approach to design the new materials for energy storage.

Solid oxide fuel cell (SOFC), as an efficient and environmentally friendly energy conversion device, has attracted much attention due to its numerous advantages, i.e., high electrical efficiency, low emissions, and high fuel flexibility, compared to other power generation technologies. To address the degradation issues faced by SOFCs operating at high temperatures, developing proton-conducting electrolytes as an alternative to oxygen-conducting electrodes is recognized as an effective strategy to lower the operating temperature of SOFCs. BZCY721 (BaZr_0.7Ce_0.2Y_0.1O_3-δ), a proton-conducting electrolyte material used in protonic ceramic fuel cells (PCFCs), exhibits both high proton conductivity and excellent chemical stability at lower temperatures. However, sintering the BZCY material typically requires high temperatures exceeding 1 700 ℃ for over 4-5 h, resulting in significant energy consumption and residual stress induced failures of components. It is thus imperative to explore advanced sintering technology to fabricate the BZCY electrolyte materials. Microwave sintering is a field-assisted sintering technique that utilizes the heat generated by the interaction between the specific microwave band and the microstructure of the material to heat the entire material, thereby achieving the desired density. This method effectively reduces the sintering temperature and significantly shortens the sintering time.

Commercial BZCY721 powder and NiO powder were mixed at a mass ratio of 20∶1, and ground in a ball mill for 24 h to obtain a homogeneous mixed powder. Subsequently, the mixed NiO-BZCY721 powder was blended with a 10% PVA solution at a mass ratio of 10∶1 for wet granulation. The granulated powder of 0.8 g was weighted and pressed into a die with a diameter of 15 mm at 350 MPa for 30 s. This process yielded circular specimens with the diameter of 15 mm and the thickness of approximately 1 mm. The experiment was repeated to produce several sets of green samples.

The samples were categorized into two groups for traditional sintering and microwave sintering experiments, respectively. The samples from the traditional sintering group were placed directly into a box furnace for debinding and sintering. The debinding process was carried out at a rate of 1 ℃/min to 400 ℃, for 2 h, then heating at 5 ℃/min to 1 600 ℃ for 6 h, and finally cooling at 5 ℃/min to 500 ℃ before naturally cooling to room temperature. In contrast, the samples from the microwave sintering group underwent the same debinding process in the box furnace but were then transferred to a microwave sintering furnace for sintering at different temperatures and holding time. The mechanical properties and electrochemical properties of the samples prepared using two sintering methods were investigated.

Based on the results by the Archimedes method, the density of samples prepared by both traditional sintering and microwave sintering exceeds 96%. The scanning electron microscopy images reveal that the samples both exhibit a high degree of density. The grain size distribution is relatively uniform. The statistical analysis of the grain size distribution demonstrates that as the microwave sintering temperature increases, the overall grain size of the resulting sample decreases, becoming more uniform. The average grain size of the sample sintered by microwave method at 1 500 ℃ is 0.49 μm, whereas the average grain size of the sample sintered by traditional method is 0.53 μm.

The impedance analysis reveals that there is a minimal variance in the impedance of the BZCY electrolyte produced by both sintering techniques when the operating temperature remains below 500 ℃. However, once the temperature surpasses 500 ℃, the impedance of the sample sintered by microwave method exceeds that of the sample sintered traditional method. This indicates that the microwave sintered sample exhibits a greater sensitivity at different operating temperatures, resulting in higher impedance values at elevated temperatures. Among the samples, the conductivity peaked in the sample sintered by traditional method at 1 600 ℃ for 6 h reaches a maximum value of 1.01×10^-3 S·cm^-1 at 650 ℃. Meanwhile, the sample sintered at 1 500 ℃ for 40 min exhibits a conductivity of 6.41×10^-4 S·cm^-1 at 650 ℃. Note that the activation energy associated with microwave sintering conductivity is only 1.071 eV.

The sample sintered by microwave method at 1 500 ℃ for 40 min exhibits the maximum hardness (i.e., an average value of 12.379 GPa). The sample sintered by traditional method at 1 600 ℃ for 6 h demonstrates a slightly lower hardness (i.e., 11.521 GPa), which is still higher than the sample sintered at 1 450 ℃. In terms of elastic modulus, the sample sintered by traditional method at 1 600 ℃ for 6 h displays the maximum elastic modulus (i.e., 194.68 GPa), slightly surpassing that of the sample sintered by microwave method at 1 500 ℃. According to the Evans and Niihara empirical formulas, the sample sintered by traditional method at 1 600 ℃ exhibits a fracture toughness of 0.280 MPa·m^1/2 and 0.305 MPa·m^1/2, respectively. Also, the sample sintered by microwave method at 1 500 ℃ has a fracture toughness of 0.359 MPa·m^1/2 and 0.347 MPa·m^1/2, respectively.

The density of the BZCY electrolyte with 5% (in mass) NiO sintering aids sintered by microwave method at 1 500 ℃ for 40 min was comparable to that of the sample sintered by traditional method at 1 600 ℃ for 6 h, achieving a density of over 96%. The grain size obtained by microwave sintering was smaller.

The impedance and conductivity of the sample produced by microwave sintering exhibited minimal differences, compared to those obtained by traditional sintering. The grain impedance at 650 ℃ measured was 34.81 Ω·cm², and the conductivity was 6.41×10^-4 S·cm^-1. The grain boundary impedance of microwave-sintered sample decreased as the operating temperature increased. This decrease could be attributed to the smaller grain size achieved by microwave sintering since a smaller grain size resulted in a greater number of grain boundaries, thereby increasing the impact on the grain boundary impedance. Furthermore, the activation energy for conductivity in microwave-sintered samples was only 1.071 eV.

The average hardness of the samples sintered by microwave sintering at 1 500 ℃ for 40 min reached 12.379 GPa, which was higher than that obtained by conventional sintering at 1 600 ℃ for 6 h. The average elastic modulus of the microwave-sintered sample reached 190.8 GPa, which was similar to that of traditional sintered samples. According to the statistics of indentation and crack length in SEM images, the crack type was radial crack. Based on the Evans and Niihara formulas, the results of microwave-sintered samples were 0.359 MPa·m^1/2 and 0.347 MPa·m^1/2 respectively, which were higher than those of conventionally-sintered samples.

Silicalite-1 zeolite membrane has a high separation performance due to its hydrophobic properties, which can preferentially permeate organic molecules and effectively block water molecules in aqueous-organic phase mixtures. However, the hydrophilic Si—OH on the surface of Silicalite-1 zeolite membrane is one of the most important reasons for the low hydrophobicity and selectivity of membrane, which preferentially adsorbs water molecules, and easily reacts with ethanol in the solution and generates Si—OC₂H₅ to block the zeolite pores. To solve the problems above, the n-octyltriethoxysilane (OTES) was grafted onto the surface of Silicalite-1 zeolite membrane to eliminate Si—OH, further improving hydrophobicity and separation ability of the membrane. The effects of mass fraction of OTES, reaction temperature and modification time on the membrane modification were investigated. The modification mechanism was analyzed, and the pervaporation stability of Silicalite-1 zeolite membrane before and after modification was compared.

A molar ratio of precursor solution was n(TEOS)∶n(TPAOH)∶n(H₂O)∶n(NaOH) of 1.00∶0.05∶75.00∶0.03. Silicalite-1 zeolite with a particle size of 400 nm was used as seeds to prepare Silicalite-1 zeolite membranes by a secondary growth method. The membranes were hydrothermally crystallized at 175 ℃ for 8 h. After washing, the membranes were calcined at 550 ℃ for 4 h to remove the template, obtaining silicalite-1 zeolite membranes.

Silicalite-1 zeolite membranes were placed in a solution with OTES as a solute and toluene as a solvent at different mass fractions of 1%-5%, and modified at 20-100 ℃ for 5-20 h. The membranes were washed with anhydrous ethanol to remove the residual solvent, and finally dried at 80 ℃ for 12 h to obtain the OTES@Silicalite-1 zeolite membranes.

The separation performance of OTES@Silicalite-1 zeolite membranes was tested by a laboratory homemade pervaporation device. The membrane flux was calculated via a weighing method, the separation factor was analyzed with the solution composition data on the feed-side and permeate-side. The physical phase composition of the membranes was determined by X-ray diffractometry. The chemical bonds and functional groups of the membranes were analyzed by Fourier transform infrared spectroscopy. The microscopic morphology and elemental distribution of the membranes were determined by scanning electron microscopy. The hydrophobicity of the membranes was analyzed via water contact angle measurement.

The separation factor of OTES@Silicalite-1 zeolite membranes shows an upward trend with the increase of the mass fraction of OTES. A part of the Si—OH on the membrane surface are replaced by OTES, and the membrane surface becomes more hydrophobic, which favors the adsorption and diffusion of ethanol molecules. At the OTES mass fraction of 3%, the OTES@Silicalite-1 zeolite membrane has the maximum separation factor. However, the separation factor decreases as the mass fraction of OTES further increases. This is possibly due to the excess OTES covering the pores on the membrane surface and affecting the transportation of ethanol. As Si—OH eliminates, the amount of Si—OC₂H₅ decreases, so the membrane flux trenda upward initially. However, the hydrophobicity of OTES hinders the water molecule transportation, thus reducing the membrane flux.

As the temperature increases, the grafting reaction is easier to accomplish, and the hydrophobicity of the OTES@Silicalite-1 zeolite membrane enhances. At 60 ℃, the membrane shows the maximum separation factor and membrane flux. However, the separation performance of the membrane decreases slightly as the temperature further increases, which is attributed to the excessive and promiscuous organic groups that block ethanol permeation, while reducing water flux.

The hydrophobicity and selectivity of the membrane improve at 5-10 h as the modification time increases. At 10 h, the membrane has the maximum separation factor. However, the separation performance of the membrane decreases sharply as the modification time further increases possibly due to the OTES cross-link with each other to form polymers, which severely block the pores of the zeolite, resulting in a significant decrease in membrane flux. Also, the transport of ethanol is impeded, thus decreasing the separation factor.

The surface modification of OTES could not damage the framework and crystal structure of Silicalite-1 zeolite membrane. It could effectively eliminate the Si—OH on the membrane surface, improve the hydrophobicity and separation performance of the membrane. The Silicalite-1 zeolite membrane showed the membrane flux of 0.92 kg·m^-2·h^-1 and the separation factor of 30.4 at 70 ℃ for 3.5%±0.1% ethanol aqueous solution, which was modified at a mass fraction of OTES of 3% and 60 ℃ for 10 h. Meanwhile, this membrane could also maintain a great stability during the pervaporation test for 120 h. This study indicated that alkylsilane grafting could be an effective measure to substantially improve the hydrophobicity and separation performance of Silicalite-1 zeolite membrane, having promising application prospects in the field of organic component recovery by pervaporation.

As a bulk solid waste in iron and steel industry, steel slag occupies a large amount of land, and causes environmental pollution, having a great burden to iron and steel industry and society. It is thus of great theoretical and practical significance to explore effective ways of steel slag recycling and utilization. Formaldehyde (HCHO) as a colorless, irritating smell of toxic gas is one of common volatile organic compounds (VOCs) in indoor air, which can cause chronic respiratory diseases, leukemia, and bronchial asthma and damage to the nervous system. Activated carbon (AC) is extensively used as an adsorbent for removal of HCHO. AC is an extraordinary adsorbent, but its adsorption efficiency for HCHO is low. The modification of AC using metal oxides (such as V₂O₅, MnO₂, CuO, Fe₂O₃, etc.) can improve the service life of AC and its formaldehyde adsorption performance. However, the preparation cost will increase due to the high price of metal oxides. Steel slag is rich in oxides of calcium, silicon, magnesium, iron, manganese, phosphorus and other elements. Therefore, the composite preparation of ecological AC by steel slag and biomass waste materials solves the problems of high modification cost, short service life and poor absorptivity, and expands a way of high value-added utilization of steel slag.

Steel slag/peanut shell activated carbon (SPAC) was firstly prepared via microwave heating and phosphoric acid activation. According to the national standard of "Formaldehyde emission limit in wood-based panels and their Products of Interior Decoration Materials" (GB18580-2017), a formaldehyde absorptivity experiment by SPAC was systematically made. The porosity of samples was determined by a model ASAP 2020M surface area & porosity analyzer based on the N₂ adsorption-desorption isotherm. The microscopic morphology of SPAC was analyzed by a model NANO SEM430 scanning electron microscope with energy disperse spectroscope (SEM-EDS). The elements content of SPAC in ultra-high vacuum with Al K_α laser radiation (hυ=1 486.6 eV) was characterized by a model ESCALAB250 X-ray photoelectron spectrometer (XPS).

The result show that the sample has an excellent removal efficiency (i.e., 93.2%) under the preparation condition of 550 W microwave power, 1.25 impregnation ratio and 15% steel slag content. The correlation coefficients of the experimental results and the fitted values for the pseudo-second-order kinetic model and the Freundlich model are 0.998 0 and 0.953 7, respectively. It is indicated that the removal process of formaldehyde on SPAC is more dominant due to chemisorption. The N₂ adsorption-desorption isotherm is a type IV adsorption isotherm with H3 and H4 hysteresis loops, indicating that the sample is a mesoporous material. Based on the results of SEM-EDS and XPS, steel slag is loaded into the SPAC sample and elements Fe and Mn have a crucial role for the absorptivity of formaldehyde. This study provided a reference for the exploration of steel slag based functional materials, and a theoretical support for the efficient formaldehyde removal at room temperature.

Steel slag powder could be loaded into the composite activated carbon. The prepared composite activated carbon still retained the porous structure characteristics suitable for removal of formaldehyde. The synergistic action of the elements Fe and Mn from steel slag powder was beneficial to improving the formaldehyde removal.

Radiation resistant optical fiber panel is a kind of optical fiber material device with special functions. As a core component of X-ray radiology, this fiber material is widely used in digital X-ray imaging, pet medical treatment, security inspection, industrial nondestructive testing and food safety testing. The industry entry threshold for radiation resistant fiber optic panels is relatively high. The existing market of high lead glass materials for radiation-resistant optical fiber panel is basically monopolized. To ensure high visible light transmittance, good thermal stability, and chemical stability of glass materials used in radiation resistant fiber optic panels, a higher content of PbO is introduced into the glass composition to further improve its refractive index and X-ray absorption performance In this paper, the main factors (i.e., temperature, atmospheric pressure and raw material) affecting the volatilization of PbO in the melt of high-lead glass for radiation-resistant optical fiber panels were analyzed.

A yellow lead was selected as a raw material to introduce lead into the glass, and the experiments were carried out at different melting temperatures. The melting temperature was optimized based on the experimental results. The atmosphere pressure of crucible kiln changed to further control the volatilization of radiation-resistant glass in the melting process. Under the optimal process conditions, a more effective way to control volatiles was explored via changing the lead oxide introduction method. Also, the volatiles of the glass melt with different raw material introduction methods were determined by energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), and the main components and contents of the volatiles were analyzed.

In the mixed materials with the same lead oxide content, the glass in the melting process of volatile amount decreases, and the volatility rate decreases from 2.00% at 1 530 ℃ to 1.53% at 1 500 ℃ as the melting temperature decreases. In addition, when the melting temperature decreases < 1 500 ℃, hard-melt substances in the glass sample appear possibly due to the enrichment of CaO, LaO and PbO. At 1 500 ℃, the volatilizing amount of glass decreases with the increase of atmospheric pressure in crucible, and the volatilizing rate decreases from 1.53% at 0 MPa to 0.80% at 0.4 MPa. When the pressure of the gas further increases, it leads to massive stripes on the surface of the glass liquid, affecting the quality of the product. At the same lead oxide content in the mixing material, melting temperature and ventilation pressure, lead oxide is introduced into the glass by two approaches, i.e., lead is introduced into the glass with yellow lead as a raw material, and lead is introduced into the glass with red lead as a raw material. Based on the results of composition test and analysis of the glass material obtained by melting, the glass in the melting process of volatile amount decreases, and the volatility rate decreases from 0.80% to 0.51% when red lead is used to introduce lead into the glass. From the EDS spectra of volatile sample, lead oxide volatilizes in glass material during melting process. As yellow lead is used as a raw material to the glass introduction, the percentage of lead atoms in the volatiles is 35.44%. As red lead is used as a raw material, the percentage of lead atoms in the volatiles is 22.21%. The XPS spectra of volatile samples with two different lead introduction methods show that element lead is the main valence state, the valence state is auxiliary.

The influences of melting temperature, ventilation pressure and raw material introduction mode on the volatiles in the glass melting process were investigated. At the melting temperature of 1 500 ℃, the ventilation pressure of 0.4 MPa, and red lead as a raw material to introduce lead into the glass, the volatile amount of volatiles in the glass melting process was effectively controlled, and the volatility of lead oxide was reduced from 2.00% to 0.51%. At the melting temperature of 1 500 ℃ and ventilation pressure of 0.4 MPa, red lead or yellow lead as a raw material to introduce lead, the valence state of Pb element in the glass melting volatiles was mainly tetravalent, and the divalent was auxiliary. The content ratio of tetravalent lead and divalent lead was 4.79 and 4.94, respectively.

Ethanol is one of volatile organic compounds. Long-term exposuring ethanol vapors can cause serious human-being health problems, such as headaches, throat irritation, and liver damage dirty. In addition, the human body will have nerve paralysis, slow brain response, and uncontrolled limbs when ethanol in the human blood reaches a certain concentration, resulting in frequent traffic accidents. It is thus necessary to develop gas sensors that can monitor ethanol in the human body. Metal oxide gas sensors have attracted much attention because of their cheap price, convenient portability and stable performance. Zn₂SnO₄ and CaFe₂O₄ are novel ternary metal oxide semiconductors with the advantages of high electron migration rate, strong gas adsorption and good thermal stability, which are widely used in gas sensors. However, single Zn₂SnO₄ or CaFe₂O₄ generally has the disadvantages of poor selectivity, high operating temperature and long response-recovery time. Some studies indicate that combining two different metal oxides to construct heterojunctions could greatly improve the gas sensing properties. It is prospected that the construction of CaFe₂O₄/Zn₂SnO₄ heterojunction is an effective method to enhance the gas sensing performance. However, little work on CaFe₂O₄/Zn₂SnO₄ composite for ethanol detection has been reported yet. In this paper, a p-n heterojunction between CaFe₂O₄ and Zn₂SnO₄ was constructed by a hydrothermal method to realize the superior gas sensing properties of CaFe₂O₄/Zn₂SnO₄ composite to detect ethanol.

To prepare Zn₂SnO₄ octahedral, 2 mmol Zn(CH₃COO)₂·2H₂O and 1 mmol SnCl₄·5H₂O were dissolved in 70 mL deionized water. Meanwhile, 0.1 g CTAB (cetyltrimethyl ammonium bromide) and 15 mmol NaOH were dissolved in the solution above. Afterwards, the solution was stirred for 40 min, transferred into a 100 mL Teflon-lined autoclave and heated at 180 ℃ for 24 h. After reaction, the powder was washed and calcined at 550 ℃ for 2 h to obtain Zn₂SnO₄ octahedral.

To prepare CaFe₂O₄ nanorods, 1 mmol CaCl₂ and 2 mmol FeCl₃ were dissolved into a mixed solution of ethanol (30 mL) and deionized water (10 mL) under stirring at room temperature for 30 min. The mixed solution was transferred into a 50 mL autoclave, heated at 180 ℃ for 12 h. After reaction, the powder was washed and dried at 80 ℃ for 8 h to obtain CaFe₂O₄ nanorods.

To prepare CaFe₂O₄/Zn₂SnO₄ composites, 2 mmol Zn(CH₃COO)₂·2H₂O and 2 mmol Zn(CH₃COO)₂·2H₂O were dissolved in 70 mL deionized water. Meanwhile, 0.1 g CTAB (cetyl trimethyl ammonium bromide) and 15 mmol NaOH were dissolved in the solution. The as-prepared CaFe₂O₄ samples were added into the Zn₂SnO₄ reaction mixture, and the mixture was stirred for 40 min, transferred into a 100 mL Teflon-lined autoclave and heated at 180 ℃ for 24 h. After reaction, the powder was washed and calcined at 550 ℃ for 2 h to obtain CaFe₂O₄/Zn₂SnO₄ composites. At different addition amounts of CaFe₂O₄ (i.e., 0.006 3, 0.012 5 g and 0.018 8 g), the CaFe₂O₄/Zn₂SnO₄ composites with different mole fractions of 2%, 4% and 6% were obtained, and marked as 2%CaFe₂O₄/Zn₂SnO₄, 4%CaFe₂O₄/Zn₂SnO₄ and 6%CaFe₂O₄/Zn₂SnO₄, respectively.

The X-ray diffraction patterns show that Zn₂SnO₄ is a perovskite structure and CaFe₂O₄ is a clinopyrite structure. The XRD pattern of CaFe₂O₄/Zn₂SnO₄ composites is close to that of Zn₂SnO₄, and no CaFe₂O₄ diffraction peaks appear, probably due to the small amount of CaFe₂O₄. For the Fourier transform infrared spectra of CaFe₂O₄/Zn₂SnO₄ composites, Ca-O, Fe-O and Sn-O bonds appear at 565, 478 cm^-1 and 574 cm^-1 in these composites, demonstrating that CaFe₂O₄/Zn₂SnO₄ composites are synthesized. In addition, compared with CaFe₂O₄ and Zn₂SnO₄, the characteristic absorption peaks of CaFe₂O₄/Zn₂SnO₄ composites all shift slightly to the right region, confirming the existence of interfacial contact between CaFe₂O₄ and Zn₂SnO₄. For the scanning electron microscopy and transmission electron microscopy images, Zn₂SnO₄ is an octahedral structure with a uniform size of approximately 350 nm, while CaFe₂O₄ has a nanorod structure with a length of approximately180 nm. For the X-ray photoelectron spectra, elements Zn, Sn, Fe, Ca and O coexist in CaFe₂O₄/Zn₂SnO₄ composites, and Zn₂SnO₄ incorporated with CaFe₂O₄ increases the oxygen vacancy defects by the Gauss peak division method.

Compared with pure CaFe₂O₄, Zn₂SnO₄ and other CaFe₂O₄/Zn₂SnO₄ sensors, 4%CaFe₂O₄/Zn₂SnO₄ sensor exhibits a prominent gas sensing performance to ethanol (i.e., a favorable selectivity to ethanol, a low detection limit of 0.07 μmol/L, fast response/recovery time of 21 s/63 s, long-term stability, and high gas response (96) toward 40 μmol/L ethanol). The superior ethanol gas sensing performance of 4%CaFe₂O₄/Zn₂SnO₄ is attributed to the formation of CaFe₂O₄-Zn₂SnO₄ p-n heterojunctions, the high content of oxygen vacancy defects, and the increased surface electron density. Therefore, CaFe₂O₄-Zn₂SnO₄ p-n heterojunction composite has a great potential application for detecting ethanol gas.

Zn₂SnO₄ octahedral, CaFe₂O₄ nanorods and CaFe₂O₄/Zn₂SnO₄ composites were prepared by a hydrothermal method. 4% CaFe₂O₄/Zn₂SnO₄ based sensor exhibited the maximum gas response of 96 μmol/L to 40 μmol/L ethanol at 400 ℃, which was 2.6 times higher than that of Zn₂SnO₄ and 34 times higher than that of CaFe₂O₄. Moreover, 4%CaFe₂O₄/Zn₂SnO₄ based sensor also achieved a long-term stability, an excellent humidity resistance, fast response-recovery time (21 s/63 s) and a low theoretical detection limit of 0.07 μmol/L for ethanol. The enhanced gas sensing properties of 4%CaFe₂O₄/Zn₂SnO₄ could be attributed to the following factors, i.e., CaFe₂O₄ coupled with Zn₂SnO₄ decreased the electron-hole recombination efficiency, and increased the surface electron density; and the formation of p-n heterojunctions between CaFe₂O₄ and Zn₂SnO₄ increased thickness of Debye electron layer, resulting in a drastic resistance change. The appropriate amount of CaFe₂O₄ coupled with Zn₂SnO₄ could be a promising strategy to enhance the sensing performance of ethanol, having great potentials in manufacturing high response and low detection limit of ethanol sensors.

Compared with conventional solid oxide fuel cell, using one material as both the cathode and anode to construct a symmetrical solid oxide fuel cell (SSOFC) configuration can simplify the fabrication processes and reduce the cost, while mitigating the chemical incompatibility and thermal mismatching issues. A-site double perovskite PrBaMn₂O_5+δ, with a matched thermal expansion coefficient with electrolytes, good structural stability in both oxidizing and reducing atmospheres as well as a modest catalytic activity is a promising symmetrical electrode. However, PrBaMn₂O_5+δ has a low electrical conductivity in reducing atmosphere and an inferior catalytic activity towards fuel oxidation. To address these issues, a lattice doping strategy was employed to regulate the charge carrier and oxygen vacancy concentrations, as well as the energy band structure. In addition, theoretical calculation could predict the properties of the material, and screen doping elements for high-performance material. The A site elements have a great impact on the properties of material in terms of structure, conductivity, and catalytic activity. In this paper, first-principles calculation was employed to investigate the effect of A-site Re (rare-earth) element species (i.e., La, Pr, Nd, Sm, Gd, and Y) on the structure and properties of ReBaMn₂O_5+δ materials, and the calculated results were verified by experimental data.

The Cambridge sequential total energy package (CASTEP) module in Material Studio software was utilized to calculate the binding energy, formation energy from oxides, and density of states (DOS) of LaBaMn₂O_5+δ (LBM), PrBaMn₂O_5+δ (PBM), NdBaMn₂O_5+δ (NBM), SmBaMn₂O_5+δ (SBM), GdBaMn₂O_5+δ (GBM), and YBaMn₂O_5+δ (YBM) materials, respectively. The selected materials were prepared by a sol-gel method. The phase structure of the synthesized powder was examined by X-ray diffraction (XRD). The electrical conductivities of the samples were measured by the DC four-terminal method in air and 5% H₂/Ar atmosphere, respectively. The electrochemical impedance spectroscopy (EIS) and current-voltage curves of the La_0.8Sr_0.2Ga_0.8Mg_0.2O_3-δ (LSGM, 300 μm) electrolyte supported symmetrical cell were obtained using Solartron 1260 with 1287.

The theoretical lattice parameters of ReBaMn₂O₆ and ReBaMn₂O₅ were obtained through geometric optimization in DFT calculation. The ReBaMnO₅ shows an enlarged lattice volume rather than that of ReBaMnO₆. Also, the lattice volume of RBM shrinks with decreasing Re³⁺ ion radius. The binding energy results show that GBM has the maximum absolute value of binding energy, indicating an intense structural stability, which is related to the half-filled electronic configuration (4f⁷) of Gd³⁺. YBM has the minimum binding energy, indicating a poor structural stability. For the formation energy, SBM and GBM show a negative formation energy from corresponding oxides, inferring an intense synthesis preference. LBM and YBM exhibit a positive formation energy, and they prefer to maintain two phases, i.e., La(Y)MnO₃ and BaMnO₃. The energy difference between the O 2p orbital center and the Fermi surface of perovskite materials is related to the catalytic activity. Based on the conduction mechanism of B—O—B small polaron of electrons in perovskite structure, the energy difference between O 2p and Mn 3d orbital center can be related to the conductivity of the material. In this regard, the DOS of ReBaMn₂O₆ and ReBaMn₂O₅ is calculated to predict the corresponding properties. The results show that ReBaMn₂O_5+δ exhibits a better catalytic activity towards oxygen reduction than fuel oxidation because of the lower energy difference between the O 2p orbital center and Fermi surface of ReBaMn₂O₆ than that of ReBaMn₂O₅. In addition, PBM shows the minimum O 2p-Fermi energy difference, indicating a superior catalytic activity. While YBM and LBM possess high these values, indicating a poor catalytic activity. For the energy difference between O 2p and Mn 3d orbital center of the material, ReBaMn₂O₆ shows a smaller value than that of ReBaMn₂O₅, inferring that a higher electrical conductivity can be obtained in oxidizing atmosphere than in reducing atmosphere. PBM and NBM exhibit lower O 2p-Mn 3d energy difference values, indicating that they can realize a high conductivity. While YBM and LBM show the opposite results, indicating a low conductivity of the material. To verify these calculation results, ReBaMn₂O_5+δ with La, Nd, and Gd A-site elements are synthesized for properties characterization.

The XRD patterns demonstrate that NBM and GBM show a tetragonal structure with P4/mmm space group in both air and 5% H₂/Ar atmosphere, while LBM sample consists of BaMnO₃, La_1-xM_1-zO₃, and MnO phases. This result is consistent with the calculation results that LBM possesses a positive formation energy, showing a thermodynamic instability. NBM and GBM exhibit a higher conductivity in air rather than in 5% H₂/Ar, and NBM displays higher conductivities than GBM. At 900 ℃, the conductivities of NBM are 48.8 S·cm^-1 and 10.0 S·cm^-1 in air and 5% H₂/Ar, respectively, which are higher than those of GBM (i.e., 38.9 and 8.8 S·cm^-1). For the EIS results, NBM and GBM-based symmetrical cells exhibit lower polarization resistance in air than that in 3%H₂O/H₂. In addition, NBM shows superior catalytic activity than GBM, as confirmed by a lower polarization resistance of NBM than GBM (i.e., 1.78 vs. 3.4 Ω·cm² in air, 2.60 vs. 3.7 Ω·cm² in 3% H₂O/H₂). The conductivity and EIS results both are in accordance with the theoretical calculation results.

The computation results indicated that LBM is not stable at single phase layered perovskite structure. GBM showed the maximum binding energy, indicating the optimum structural stability, while NBM exhibited a smaller energy difference between Mn 3d and O 2p orbital center, and a lower energy difference between the O 2p orbital center and Fermi surface, implying the good conductivity and excellent catalytic activity among the investigated materials. Based on the calculation results, La, Nd and Gd were selected as A-site elements for verification. The results manifested that LBM was difficult to form single-phase perovskite, but it was easy to synthesize the single phases NBM and GBM. They showed a good structural stability in both reducing and oxidizing atmospheres. NBM exhibited higher conductivities in both air and 5% H₂/Ar, compared to GBM. In addition, NBM electrode displayed much lower polarization resistance than GBM, demonstrating a superior catalytic activity. The LSGM electrolyte (300 μm) supported symmetrical cell with NBM electrode delivered a maximum power density of 335 mW·cm^-2 at 850 ℃.