The ex vivo application of enzymes in various processes, especially via enzyme immobilization techniques, has been extensively studied in recent years in order to enhance the recyclability of enzymes, to minimize enzyme contamination in the product, and to explore novel horizons for enzymes in biomedical applications. Possessing remarkable amenability in structural design of the frameworks as well as almost unparalelled surface tunability, Metal-Organic Frameworks (MOFs) have been gaining popularity as candidates for enzyme immobilization platforms. Many MOF-enzyme composites have achieved unprecedented results, far outperforming free enzymes in many aspects. This review summarizes recent developments of MOF-enzyme composites with special emphasis on preparative techniques and the synergistic effects of enzymes and MOFs. The applications of MOF-enzyme composites, primarily in transferation, catalysis and sensing, are presented as well. The enhancement of enzymatic activity of the composites over free enzymes in biologically incompatible conditions is emphasized in many cases.

Aqueous zinc-ion batteries (ZIBs) have been intensively investigated as potential energy storage devices on account of their low cost, environmental benignity, and intrinsically safe merits. With the exploitation of highperformance cathode materials, electrolyte systems, and in-depth mechanism investigation, the electrochemical performances of ZIBs have been greatly enhanced. However, there are still some challenges that need to be overcome before its commercialization. Among them, the obstinate dendrites, corrosion, and hydrogen evolution reaction (HER) on Zn anodes are critical issues that severely limit the practical applications of ZIBs. To address these issues, various strategies have been proposed, and tremendous progress has been achieved in the past few years. In this article, we analyze the origins and effects of the dendrites, corrosion, and HER on Zn anodes in neutral and mildly acid aqueous solutions at first. And then, a scientific understanding of the fundamental design principles and strategies to suppress these problems are emphasized. Apart from these, this article also puts forward some requirements for the practical applications of Zn anodes as well as several cost-effectivemodifying strategies. Finally, perspectives on the future development of Zn anodes in aqueous solutions are also briefly anticipated. This article provides pertinent insights into the challenges on anodes for the development of highperformance ZIBs, which will greatly contribute to their practical applications. K E Y W O R D S corrosion, hydrogen evolution reaction, Zn anode, Zn dendrites 1 | INTRODUCTION As a result of the ongoing crisis in the depletion of conventional fossil fuels, renewable clean energy sources, such as solar energy, wind energy, hydropower, geothermal, and nuclear energy, are rapidly developing. 1,2 Nevertheless, it remains an extreme challenge to efficiently store the energy generated by those renewable

Mixtures of copper and iron oxides are used as industrial catalysts for the water-gas shift (WGS, CO + H 2 O f H 2 + CO 2 ). In-situ time-resolved X-ray diffraction, X-ray absorption fine structure, and atomic pair distribution function analysis were used to study the reduction of CuFe 2 O 4 with CO and the behavior of CuFe 2 O 4 and Cu/Fe 2 O 3 catalysts under WGS reaction conditions. MetalToxygenTmetal interactions enhance the stability of Cu 2+ and Fe 3+ in the CuFe 2 O 4 lattice, and the mixed-metal oxide is much more difficult to reduce than CuO or Fe 2 O 3 . Furthermore, after heating mixtures of CuFe 2 O 4 /CuO in the presence of CO or CO/H 2 O, the cations of CuO migrate into octahedral sites of the CuFe 2 O 4 lattice at temperatures (200-250 °C) in which CuO is not stable. Above 250 °C, copper leaves the oxide, the occupancy of the octahedral sites in CuFe 2 O 4 decreases, and diffraction lines for metallic Cu appear. From 350 to 450 °C, there is a massive reduction of CuFe 2 O 4 with the formation of metallic Cu and Fe 3 O 4 . At this point, the sample becomes catalytically active for the production of H 2 from the reaction of H 2 O with CO. Neutral Cu 0 (i.e., no Cu 1+ or Cu 2+ cations) is the active species in the catalysts, but interactions with the oxide support cannot be neglected. These studies illustrate the importance of in situ characterization when dealing with mixed-metal oxide WGS catalysts.

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A long-wavelength photoabsorption of organic molecules has been noticed because of the potential as materials. In addition to the extension of π conjugation, molecular aggregation has been utilized to realize the elongation of absorption wavelength. We report strong near-infrared absorptions of trioxotriangulene neutral radicals in the crystalline state and large-scale theoretical calculations of the radical assemblies interpreting the mechanism of optical properties. Polarized absorption spectra and X-ray diffraction of the crystals clarified that an unusual π-stacking column consisting of π-dimers is key for this absorption. Quantum chemical calculations based on time-dependent density functional theory revealed that the π-dimer shows an electronic transition between frontier orbitals generated by strong coupling of the delocalized singly occupied orbitals of monomers. The interdimer interaction of transition dipole moments, which are parallel to the column, elucidated the increase of absorption wavelength. The divide-andconquer Green function method enabled the large-scale time-dependent density functional theory calculation up to a 60mer, where the maximum number of atoms is 4380, reproducing the near-infrared absorptions of trioxotriangulene crystals. The present method to investigate the mechanism of the long-wavelength photoabsorption is useful for developing organic materials consisting of stable neutral radicals.

The performance of low-temperature solid-oxide fuel cells (LT-SOFCs) is heavily dependent on the electrocatalytic activity of the cathode toward the oxygen reduction reaction (ORR).

Although tremendous efforts have been devoted to the exploration of cost-effective, active, and stable electrochemical catalysts, only few significant breakthroughs have been achieved up to now. Therefore, exploring new catalysts and improving catalyst activity and stability are still major tasks at present. Controllable synthesis of Pt-based alloy nanocrystals with a uniform high-index surface and unique architecture has been regarded as an effective strategy to optimize their catalytic efficiency toward electrochemical reactions. Accordingly, here we present a one-pot facile solvothermal process to synthesize novel unique Cu@CuPt core-shell concave octahedron nanocrystals that exhibit both outstanding activity and long durability. By regulating temperatures during the synthesis process, we were able to control the reduction rate of Cu and Pt ions, which could subsequently lead to the sequential stacking of Cu and Pt atoms. Owing to the concave structure, the as-prepared core-shell nanoparticles hold a high-index surface of {312} and {413}. Such surfaces can provide a high density of atomic steps and terraces, which is suggested to be favorable for electrochemical catalysts. Specifically, the Cu@CuPt core-shell concave octahedron presents 8.6/13.1 times enhanced specific/mass activities toward the methanol oxidation reaction in comparison to those of a commercial Pt/C catalyst, respectively. Meanwhile, the as-prepared catalyst exhibits superior durability and antiaggregation properties under harsh electrochemical conditions. The facile method used here proposes a novel idea to the fabrication of nanocrystals with desired compositional distribution, and the as-prepared product offers exciting opportunities to be applied in direct methanol fuel cells.

Increasing evidence has shown that plasticizer pollution and waste fatty acid contamination are serious environmental issues in our daily lives. Herein, an environmental friendly plasticizer (waste momomer fatty acid-based methyl tetraglycol ester, WMA-MTE) was designed and prepared via the direct esterification of waste momomer fatty acid derived from dimer acid manufacturing and methyl tetraglycol. The resulting WMA-MTE was used as a potential alternative for toxic petro-based dioctyl phthalate (DOP) in plasticizing poly­(vinyl chloride) (PVC). The properties of plasticized PVC including low temperature capability, tensile properties, thermal stability, and migration resistance were dependent on the content of WMA-MTE. Among them, the overall performances of PVC plasticized with 100% WMA-MTE (PVC/WMA-MTE) were better than others, which could be attributed to the excellent abilities of oxethyl units in WMA-MTE in both improving the compatibility and flexibility. Importantly, WMA-MTE could be biodegraded only by being buried in soil. All the above results suggest that WMA-MTE is an attractive alternative to DOP in the PVC industry.