Exfoliation of Metal-Organic Frameworks to Give 2D MOF Nanosheets for the Electrocatalytic Oxygen Evolution Reaction.

The structure and properties of materials are determined by a diverse range of chemical bond formation and breaking mechanisms, which greatly motivates the development of selectively controlling the chemical bonds in order to achieve materials with specific characteristics. Here, an orientational intervening bond-breaking strategy is demonstrated for synthesizing ultrathin metal-organic framework (MOF) nanosheets through balancing the process of thermal decomposition and liquid nitrogen exfoliation. In such approach, proper thermal treatment can weaken the interlayer bond while maintaining the stability of the intralayer bond in the layered MOFs. And the following liquid nitrogen treatment results in significant deformation and stress in the layered MOFs' structure due to the instant temperature drop and drastic expansion of liquid N2, leading to the curling, detachment, and separation of the MOF layers. The produced MOF nanosheets with five cycles of treatment are primarily composed of nanosheets that are less than 10 nm in thickness. The MOF nanosheets exhibit enhanced catalytic performance in oxygen evolution reactions owing to the ultrathin thickness without capping agents which provide improved charge transfer efficiency and dense exposed active sites. This strategy underscores the significance of orientational intervention in chemical bonds to engineer innovative materials.

Prussian blue analogue derived from leather waste as a bifunctional catalyst in zinc-air batteries.

A Prussian blue analogue was synthesized using biomass leather waste as a precursor by doping with Co2+ ions. This material, demonstrates good performance in both the oxygen reduction reaction and oxygen evolution reaction, and exhibits excellent charge-discharge performance and stability in zinc-air batteries.

Achieving High Ionic Conductivity and Mechanical Strength by a Leather Gel Electrolyte for Flexible Zinc-Ion Batteries.

The continuous advancement in the field of flexible and wearable electronics has led to increased research interest in safe, low-cost, and flexible zinc-ion batteries, particularly with a focus on flexible electrolytes. In this study, we present a leather gel electrolyte (LGE) that offers robust mechanical properties and an excellent electrochemical performance. LGE exhibits an ionic conductivity of 1.36 × 10-2 S cm-1 and achieves a capacity of 303.7 mAh g-1 in flexible zinc-manganese dioxide batteries. Even after 1000 cycles, the capacity retention remains above 90%, demonstrating outstanding performance in protecting the zinc anode. Furthermore, such a flexible battery shows good resistance to damage due to the strong mechanical strength originating from leather. Notably, LGE utilizes green and sustainable leather as a raw material, making it a promising option for sustainable flexible devices.

Recent Progress in Surface and Interface Engineering for Electrocatalytic CO2 Reduction.

The conversion of CO2 through CO2 reduction reaction (CO2 RR) into valuable products has potential to lessen the greenhouse effect caused by uncontrolled CO2 emissions. Challenges of CO2 RR reaction lie in the stabilization of the reaction intermediate and the activation of the inert chemical bond of CO2 , but the application of CO2 RR at large scale is limited by the high cost and structural instability of traditional catalysts. By applying CO2 RR catalyst with delicate structure of stable CO2 intermediate to industrial production, the problems such as high cost of CO2 conversion, low catalytic selectivity and poor catalytic efficiency can be effectively solved, showing better application value and significance than traditional catalysts. This review focuses on the defects, and metal-support interaction (MSI) effect to modify the catalyst and other strategies to enhance the effectiveness of CO2 reduction. The challenges and prospects from the three perspectives are also discussed to provide suggestions for the designing of efficient CO2 RR catalysts in the future. This review offers new insights and research perspectives of reducing CO2 emission through recycling CO2 , and neutralizing the carbon cycle.

Synthesis of High-Loading Pt/C Electrocatalysts Using a Surfactant-Assisted Microwave Discharge Method for Oxygen Reduction Reactions.

High-loading Pt/C catalysts play an important role in the practical application of metal-air batteries and fuel cells because of their superior activity, high conductivity, and commercial availability. It is well known that high loadings always lead to the agglomeration of Pt nanoparticles, resulting in a loss of catalytic activity and stability; thus, it still remains a challenge to prepare high-loading Pt/C catalysts with high dispersion and small particle sizes. Here, we introduce a surfactant-assisted microwave discharge method to prepare high-loading (>40 wt %) Pt/C electrocatalysts with ultrafine particle sizes (∼3.19 nm) and good dispersion. Benefitting from the high-temperature property and reducibility of carbon-induced-arc, the surfactant and Pt precursors undergo rapid decomposition, reduction, and carbonization, generating the structure of Pt@C on carbon black. The carbon derived from the surfactant can not only inhibit the agglomeration of Pt nanoparticles but also prevent the Pt core from toxication, ensuring high activity and stability of the high-loading Pt/C catalyst. When evaluated in the oxygen reduction reaction, the as-prepared Pt/C catalyst demonstrates a comparable activity and better methanol resistance to commercial Pt/C.

Chemo-Biocascade Reactions Enabled by Metal-Organic Framework Micro-Nanoreactor.

The one-pot combination of biocatalytic and chemocatalytic reactions represents an economically and ecologically attractive concept in the emerging cascade processes for manufacturing. The mutual incompatibility of biocatalysis and chemocatalysis, however, usually causes the deactivation of catalysts, the mismatching of reaction dynamic, and further challenges their integration into concurrent chemo-biocascades. Herein, we have developed a convenient strategy to construct versatile functional metal-organic framework micro-nanoreactors (MOF-MNRs), which can realize not only the encapsulation and protection of biocatalysts but also the controllable transmission of substances and the mutual communication of the incompatible chemo-biosystems. Importantly, the MOFs serving as the shell of MNRs have the capability of enriching the chemocatalysts on the surface and improving the activity of the chemocatalysts to sufficiently match the optimum aqueous reaction system of biocatalysts, which greatly increase the efficiency in the combined concurrent chemo-biocatalysis. Such strategy of constructing MOF-MNRs provides a unique platform for connecting the "two worlds" of chemocatalysis and biocatalysis.