Latest ArticlesThe lithium dendrite growth is still a serious challenge and impeding the realistic applications of all-solid-state lithium batteries. In view of the amide containing sediment layer can be stable on lithium/cathodes, a composite polymer electrolyte with amide-based matrix is in-situ built on porous electrodes. With the introduction of amide, the polymer electrolyte presents excellent ability to inhibit lithium dendrite growth and makes the Li/Li symmetric battery stably work for 500 h with a good ionic conductivity of 4.25 × 10−5 S/cm at 40 ℃. The solid electrolyte also shows a wide electrochemical stable window and good interface contact with the porous cathode. Utilizing this composite polymer electrolyte, the all-solid-state Li/LiFePO4 battery shows an initial discharge capacity of 146.5 mAh/g at 0.1 C under 40 ℃ and remains 81.4% in 100 cycles. The polymer electrolyte also can present better properties after modification. These results demonstrate that the presented PA-based composite polymer electrolyte could be served as a good electrolyte candidate for all-solid-state lithium-ion batteries.
Surface-enhanced Raman scattering (SERS) spectroscopy has been employed as a rapid analysis technology for food security inspection recently. Nowadays, it is still a great challenge to rapidly quantify multiple trace antibiotics potentially abused in aquaculture industry. In this work, a magnetic Ti3C2Tx/Fe3O4/Ag substrate was prepared for the development of a reliable rapid SERS quantification method for multiple trace sulfonamides in aquatic products. This magnetic substrate had good uniformity, reproducibility, stability and SERS activity. Moreover, this substrate could integrate the magnetic separation-enrichment and matrix clean-up without cross contamination, which endowed it with good selectivity and anti-interference capability during real sample analysis. The electromagnetic enhancement and chemical enhancement mechanism of this magnetic substrate were studied in detail to reveal its good separation-enrichment performance and SERS activity. Finally, a rapid SERS quantification method was established and practically applied for trace phthalic sulfathiazole (PST) and silver sulfadiazine (SSD) in aquatic products by using Ti3C2Tx/Fe3O4/Ag magnetic substrates. Trace PST and SSD could be actually detected and quantified as 55.9 µg/kg and 64.0 µg/kg in aquatic products, respectively. Good recoveries of 83.9%–116% with relative standard deviations (RSDs) of 0.5%–3.2% for PST and 80.2%–102% with RSDs of 1.3%–5.8% for SSD were obtained. This work proposed an efficient and reliable method for rapid quantification of trace multiple sulfonamides in complex aquatic samples during food security inspection.
Selective hydrogenation of cinnamaldehyde (CAL) toward cinnamyl alcohol (COL) is an extremely important and challenging reaction. Herein, a series of PtxFey-Al2O3 bimetallic catalysts with varied Pt to Fe ratios were prepared by incipient wetness impregnation method. The introduction of Fe significantly modifies the electronic and surface properties of Pt, which clearly enhances the C=O hydrogenation selectivity. Among all the catalysts, Pt3Fe-Al2O3 displays the best catalytic performance and the conversion of CAL is 96.6% with 77.2% selectivity of COL within 1 h. In addition, Pt3Fe-Al2O3 had excellent reusability with 76% COL selectivity after five runs of the recycle process. Further characterization of the fresh, used and cycled catalysts revealed that the structure and electronic state of the synthesized PtxFey-Al2O3 are unchanged after hydrogenation reaction. The identical-location transmission electron microscopy (IL-TEM) results revealed that the interaction between the nanoparticles and the supports was strong and the catalyst was relatively stable.
Peroxymonosulfate (PMS) activation in heterogeneous processes is a promising water treatment technology. Nevertheless, the high energy consumption and low efficiency during the reaction are ineluctable, due to electron cycling rate limitation. Herein, a new strategy is proposed based on a quantum dots (QDs)/PMS system. Co-ZnS QDs are synthesized by a water phase coprecipitation method. The inequivalent lattice-doping of Co for Zn leads to the generation of surface sulfur vacancies (SVs), which modulates the surface of the catalyst to form an electronic nonequilibrium surface. Astonishingly, the plasticizer micropollutants can be completely degraded within only tens of seconds in the Co-ZnS QDs/PMS system due to this type of surface modulation. The interfacial reaction mechanism is revealed that pollutants tend to be adsorbed on the cobalt metal sites as the electron donors, where the internal electrons of pollutants are captured by the metal species and transferred to the surface SVs. Meanwhile, PMS adsorbed on the SVs is reduced to radicals by capturing electrons, achieving effective electron recovery. Dissolved oxygen (DO) molecules are also easily attracted to catalyst defects and are reduced to O2•−, further promoting the degradation of pollutants.
Hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) have been considered as two critical processes in the field of electrocatalytic water-splitting for hydrogen production and fuel cells. However, the sluggish reaction kinetics of HER and ORR required efficient electrocatalyst such as Pt to promote such process. Transition metal phosphides (TMPs) exhibit great potential to replace noble metal electrocatalysts to accelerate HER and ORR due to their high activity and easy availability. Herein, a highly-efficient bifunctional CoP electrocatalyst for HER and ORR, featuring a unique core-shell structure decorated on nitrogen-doped carbon matrix was designed and constructed via etching a cobalt-based zeolitic imidazolate framework (ZIF-67) with phytic acid (PA) followed by pyrolysis treatment (PA-ZIF-67–900). Experimental results revealed that the pure-phase single-crystalline CoP exhibited outstanding electrocatalytic performance in HER and ORR, superior to Co(PO3)2 in PA-ZIF-67–700, hybrid phase of Co(PO3)2 and CoP in PA-ZIF-67–800 and Co2P-doped CoP in PA-ZIF-67–1000. To reach the current density of 10 mA/cm2 the as-synthesized CoP required an overpotential of 120 mV for HER in 1 mol/L KOH and half-wave potential of 0.85 V in O2-saturated 0.1 mol/L KOH. This work present new clue for construction of efficient and bifunctional electrocatalyst in the field of energy conversion and storage
Green hydrogen production and CO2 fixation have been identified as the fundamental techniques for sustainable economy. The open challenge is to develop high performance catalysts for hydrogen evolution reaction (HER) and CO2 electroreduction (CO2ER) to valuable chemicals. Under such context, this work reported computational efforts to design promising electrocatalyst for HER and CO2ER based on the swarm-intelligence algorithm. Among the family of transition-metal phosphides (TMPs), Pt2P3 monolayer has been identified as excellent bifunctional catalysts due to high stability, excellent conductivity and superior catalytic performance. Different from typical d-block catalysts, p-band center presented by P atoms within Pt2P3 monolayer plays the essential role for its reactivity towards HER and CO2ER, underlining the key value of p-electrons in advanced catalyst design and thus providing a promising strategy to further develop novel catalysts made of p-block elements for various energy applications.
The unveiling of MOF growth mechanism is hampered by the lack of fundamental knowledge about the very early stage of nucleation, especially the form and ratio of molecular species in the solution for crystal growth. Herein, we report the detection of growth species for a series of MOFs with mono-linker, Cu-MOF-2-BDC and Cu-MOF-2-NDC, and two linkers, MTV-MOF-2-(C4H4), by high resolution ESI-MS, where a large variety of Cu-containing species are identified unambiguously. The solvent molecules such as H2O, methanol and DMF participate in the formation of these species, other than ethanol. Furthermore, in the growth solution of MTV-MOF-2-(C4H4), growth species containing two different organic linkers are observed. The feeding ratio is not the only factor controlling the distribution of growth species for MTV-MOFs, but also the solvent involves in coordination, an aspect usually overlooked previously.
As a member of the curcuminoid compound family, curcumin (Cur) has many interesting therapeutic properties. However, its low aqueous solubility and stability have resulted in poor bioavailability and restricted clinical efficacy. Based on size matching, β-cyclodextrin polymer (β-CDP), with its hydrophilic polymer chains and hydrophobic cavities, can form an inclusion complex with Cur. To improve the water solubility and stability of Cur, a simple and eco-friendly grinding method was designed to form β-CDP inclusion complexes. According to the Boltzmann–Hamel's method and Job's method, the molar ratio of the β-CD unit in β-CDP to Cur was determined to be 1 : 1. The diffusion coefficient and diffusion activation energy of Cur-β-CDP were calculated in an electrochemical study. This supramolecular complex worked well in vitro to inhibit the proliferation of hepatoma carcinoma cells HepG2. Remarkably, this method visibly reduced the undesirable side effects on normal cells, without weakening the anti-cancer activity of the drugs. We expect that the obtained host–guest complex will provide a new approach for delivering natural drug molecules, having low water solubility.
Quasi-two-dimensional (q2D) conducting polymer thin film synergizes the advantageous features of long-range molecular ordering and high intrinsic conductivity, which are promising for flexible thin film-based micro-supercapacitors (MSCs). Herein, we present the high-performance flexible MSCs based on highly ordered quasi-two-dimensional polyaniline (q2D-PANI) thin film using surfactant monolayer assisted interfacial synthesis (SMAIS). Owing to high electrical conductivity, rich redox chemistry, and thin-film morphology, the q2D-PANI MSCs show high volumetric specific capacitance (ca. 360 F/cm3) and energy density (17.9 mWh/cm3), which outperform the state-of-art PANI thin-film based MSCs and promise for future flexible electronics.
Lithium–sulfur (Li–S) battery is labeled as a promising high-energy-density battery system, but some inherent drawbacks of sulfur cathode materials using relatively complicated techniques impair the practical applications. Herein, an integrated approach is proposed to fabricate the high-performance rGO/VS4/S cathode composites through a simple one-step solvothermal method, where nano sulfur and VS4 particles are uniformly distributed on the conductive rGO matrix. rGO and sulfiphilic VS4 provide electron transfer skeleton and physical/chemical anchor for soluble lithium polysulfides (LiPS). Meanwhile, VS4 could also act as an electrochemical mediator to efficiently enhance the utilization and reversible conversion of LiPS. Correspondingly, the rGO/VS4/S composites maintain a high reversible capacity of 969 mAh/g at 0.2 C after 100 cycles, with a capacity retention rate of 82.3%. The capacity fade rate could lower to 0.0374% per cycle at 1 C. Moreover, capacity still sustains 795 mAh/g after 100 cycles in the relatively high-sulfur-loading battery (6.5 mg/cm2). Thus, the suggested method in configuring the sulfur-based composites is demonstrated a simple and efficient strategy to construct the high-performance Li–S batteries.