Cordierite glass-ceramics exhibit low dielectric constant, dielectric loss and thermal expansion. The stoichiometric cordierite MgO-Al₂O₃-SiO₂ (MAS) glass is due to the surface crystallization. In this paper, MAS glass-ceramics with various contents of TiO₂ as a nucleation agent were prepared by a melting method and subsequent heat treatment. The effect of TiO₂ content on the crystallization behavior and properties was investigated. The results show that the glass transition temperature and the first crystallization peak temperature decrease with the increase of TiO₂ content, indicating that TiO₂ can effectively promote the crystallization. TiO₂ enters into the glass network structure, and facilitates the formation of μ-cordierite and magnesium aluminum titanate crystalline phases in the glass, and then form α-cordierite at a higher temperature. The crystallization mechanism of glass with more than 5% (in molar fraction) TiO₂ becomes the bulk crystallization. As TiO₂ content increases to 10%, the glass-ceramics heat-treated at 800 ℃ for 10 h and 1 000 ℃ for 5 h have a high density of 2.95 g/cm³, a hardness of 9.67 GPa, and a thermal conductivity of 2.13 W/(m·K). At 8.2-12.4 GHz, its dielectric constant is 6.3-6.5 and the dielectric loss fluctuates from 10^-2 to 10^-3. At 1 MHz, the dielectric constant is 10.8 and the dielectric loss is 0.024 4.

Solar arrays can convert light energy into electrical energy as an important component of spacecraft energy systems. And solar cells made of photovoltaic effect are an important carrier of energy acquisition. Through the development and application from Si solar cell to GaAs solar cell and from single junction to multi-junction technology, this review analyzed the current situation and bottlenecks of various space solar cells combined with the lattice mismatch, multi-node growth, flip-chip structure and thin film solar cell preparation technology. According to the structural composition and rigidity of the substrate, the characteristics and future development directions of body-mounted, rigid, semi-rigid, flexible and concentrator solar arrays were described to provide a technical support for the realization of high efficiency, light weight, high quality power ratio battery circuit energy function.

It is imminent to develop and utilize solar energy to solve the increasingly serious environmental crisis. In order to improve the utilization rate of sunlight and the performance of photocatalysts, this work innovatively proposed to prepare Z-Scheme MoS₂/RGO/Fe₂O₃ ternary composites by an in-situ growth method combined with a surface electrostatic adsorption method.MoS₂/RGO hetero-structured binary composites were firstly synthesized by a hydrothermal method, and then all-solid-state Z-Scheme MoS₂/RGO/Fe₂O₃ photocatalyst was constructed via adjusting the solution pH value to create the same charges of MoS₂ and Fe₂O₃ and the opposite charges of RGO and MoS₂. According to the results by scanning electron microscopy and transmission electron microscopy, MoS₂ nanosheets and Fe₂O₃ nanoparticles are uniformly distributed on the surface of two-dimension RGO, and MoS₂ nanosheets and Fe₂O₃ nanoparticles display a stable hetero-structure onto RGO nanosheets. The RGO-based all-solid-state Z-Scheme photocatalyst possesses a superior photocatalytic reduction degradation performance under the simulated solar-driven illumination. Especially, the all-solid-state Z-Scheme photocatalyst MR0.43F has the optimum photoreduction degradation efficiency within 60 min for heavy metal Cr (VI) in a solution as a degradation indicator, which is 1.5 times greater than that of binary MoS₂/RGO composites. The all-solid-state Z-Scheme photocatalyst has wide-spectrum absorption, high separation efficiency of photogenerated carriers and surface chemical reaction efficiency, thus improving the photocatalytic properties.

The morphology of nanomaterials can affect their electrochemical performance. It is a challenge to design metal oxide nanostructures with controllable morphology/size and good electrical conductivity for their application in electrochemical supercapacitors and other energy storage devices. NiMn₂O₄ electrode materials with different amounts of polyvinylpyrrolidone (PVP) were prepared by a co-precipitation method. The effect of PVP (0, 0.2, 0.4, 0.8 g) amount on the microstructure and capacitance properties of NiMn₂O₄ was investigated. The results show that the microstructure of NiMn₂O₄ changes from an agglomerated granular to loose flocculent and fine powder with the increase of PVP content. The optimum capacitance performance of NiMn₂O₄ can be obtained at PVP amount of 0.4 g, and the specific capacitance of NiMn₂O₄ is 1 464 F/g at a current density of 1 A/g. At PVP amount of 0.8 g, the excessive amount of PVP is easy to cause residue in NiMn₂O₄ in the cleaning process. During the electrochemical test, the amount of active substances involved in the redox reaction is relatively reduced, leading to the decrease of the capacitance performance of NiMn₂O₄-0.8. The specific capacitance is 1 010 F/g when a current density is 1 A/g.

Combining the photocatalytic activity with the superhydrophobicity of coating is an effective approach for the self-cleaning effect. In this paper, the porous aluminum surface was coated with trialkoxy-terminated polydimethylsiloxane/titanium dioxide (PDMS/TiO₂) coating (APT) by a solution immersion method. According to the analysis by Fourier-transformed infrared spectroscopy and X-ray photoelectron spectroscopy, a bond (Ti—O—Si) between PDMS and TiO₂ is formed. The results by scanning electron microscopy and energy dispersive spectroscopy show that the superhydrophobicity is due to the interconnected hierarchical sheet structure and the PDMS with a low surface energy. The surface of APT coating has a stable superhydrophobicity with a water contact angle (WCA) of 161.6° and a sliding angle of less than 10°. The stability of superhydrophobicity with WCAs greater than 150° remains after 24 h ultraviolet irradiation. The ATP coating has an effective photocatalytic activity and an ability to degrade dyes and remove some organic substances on the surface.

Silver anode for direct carbon solid oxide fuel cell (DC-SOFC) has great chemical stability and resistance to sulfur and carbon deposition. However, the electrochemical performance of DC-SOFC is still unsatisfactory due to the poor catalytic performance. Strontium cobalt doped lanthanum ferrite (LSCF) is an electrode material with good catalytic performance as well as electronic and ionic conductivity. In this paper, silver anode (silver-gadolinium doped cerium oxide, Ag-GDC) was modified with LSCF to improve the catalytic performance of the silver anode and the output performance of the corresponding cell. At 850 ℃, the maximum power density of the corresponding DC-SOFC increases from 224 mW/cm² to 264 mW/cm². According to the results by impedance spectroscopy for the corresponding half-cell, microscopic morphology and crystal structure of the electrode material, and constant current discharge tests, the polarization resistance of Ag-GDC decreases from 0.543 Ω·cm² to 0.373 Ω·cm², the microstructure and crystal structure of the electrode become stable, and the fuel utilization of the corresponding cell increases from 51.3% to 57.9% after the LSCF modification. Therefore, LSCF-modified Ag-GDC is an ideal anode material for DC-SOFC with good performance and chemical stability, which is expected to promote the further development of DC-SOFC.

The energy crisis and environmental pollution are the existing global problems for humanbeings. It is a priority to reduce the emission of carbon dioxide (CO₂) and other greenhouse gases and to achieve carbon neutrality. The "artificial ecological cycle" for "(energy supply-storage-consumption-resupply)" enables to recycle and obtain material and energy via the consumption of CO₂ to alleviate these problems. Aerogels with a ultra-high porosity, a large specific surface area and a ultra-low density, and a continuous three-dimensional network structure can provide abundant charge transfer channels, and can be used as carriers to dope or load various organic or inorganic active materials to obtain composite materials with excellent catalytic performance for a wide range of applications in "artificial ecological cycle" system, i.e., photochemistry, electrochemistry, energy storage materials and other fields. In this review, we outlined the relevant applications of aerogels in photochemistry, electrochemistry, artificial nitrogen fixation, hydrogen storage and thermoelectric materials in the artificial ecological cycle, as well as outlooked the development prospects of aerogels.

In recent years, research concerning layered double hydroxides (LDHs) topological transformation materials in the field of photocatalysis and electrocatalysis, such as hydrogen production, and chemical transformation of C1 species, has been widely reported. Research shows that not only the dispersion of active site can be improved, but also phase composition, specific crystal plane and interface structure can be regulated by selecting different calcination temperature, atmosphere and other topological transformation conditions. This kind of materials thus exhibits superior performance in catalytic conversion and utilization of various energy sources. In this review, we will introduce the process and mechanism of LDHs topological transformation, and then review the research progress of LDHs topological transformation materials in energy catalysis from the aspects of photocatalysis and electrocatalysis.

The tetrahedral amorphous carbon (ta-C) films were fabricated by 45° double-bent filtered cathodic vacuum arc technique, and the wettability, surface energy, roughness, surface topography, friction coefficient and microstructure evolution of ultrathin ta-C film as functions of incident angles of carbon ions were investigated. The results reveal that as the incident angle of carbon ions increases from 0° to 60°, the water contact angle of films slightly increases from 77.6° to 82.4° and the glycerin contact angle of films slightly increases from 64.7° to 71.2°, indicating that all the films are hydrophilic. The total surface energy decreases from 33.9 mJ/m² to 28.0 mJ/m². The slight increase of observed contact angle is attributed to the decrease of surface energy and increase of surface roughness. Also, the average friction coefficient increases from 0.140 to 0.217. According to the near edge X-ray absorption fine structure data, little change for the hybridized sp³ bond content in the deposited ta-C films appears, regardless of the change of incident angle in a range of 0°-60°.

Improving the thermal stability of silica (SiO₂) aerogel plays a crucial role in expanding its heat insulation application. In this work, heat treatment in argon atmosphere was adopted to avoid the thermal oxidative decomposition of hydrophobic groups, which inevitably occurred in the heat treatment in air atmosphere. Also, the physicochemical properties were analyzed. The results show that the hydrophobicity of SiO₂ aerogels still maintains at a contact angle of 140° after heat treatment in argon atmosphere at 700 ℃. In the differential scanning calorimetry test in air atmosphere, the peak temperature in exothermic reaction (T_peak) of heat treated SiO₂ aerogels reaches 584 ℃, which is approximately 300 ℃ higher than that of untreated SiO₂ aerogels, thus improving the thermal stability. The results obtained also indicate that hydrophobic SiO₂ aerogels could be used at high temperatures due to the improved thermal stability and safety.