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Wood‐derived carbons demonstrate great potential as self‐standing electrodes in energy storage/conversion applications, including supercapacitors and water‐splitting devices. However, the key challenge remains the rational customization of surface functionalities for optimized performance. This study introduces an innovative approach to self‐standing wood‐derived carbons with tailored nitrogen and metal functionalities. In contrast to traditional impregnation techniques, which offer limited precision in surface modification, this approach entails the intentional attachment of amidoxime groups to the wood substrates. These groups serve as nitrogen sources, and create abundant surface anchoring sites for metal ions due to the chelation between the amidoxime groups and metals. The resulting carbons feature uniform and high dispersion of nitrogen and metal functionalities, along with a distinctive hierarchical porosity combining interconnected open channels with abundant mesopores. As a proof‐of‐concept, different metals are incorporated (i.e., Mn, Co, Ni) into the amidoximated‐wood precursors, and the resulting self‐standing carbons showcase excellent performance in both supercapacitors and water‐splitting applications. Leveraging the specific chelating ability of amidoxime groups toward metal ions, this strategy holds great potential as a generic approach to systematically tailoring the surface functionalities of carbon‐based materials for various electrochemical energy storage/conversion processes. [ABSTRACT FROM AUTHOR]

The oxygen reduction reaction (ORR) represents a cornerstone for many clean energy conversion technologies such as fuel cells and metal‐air batteries. Nevertheless, the commercialization of these technologies is largely impeded by the slow kinetics of ORR, for which active, durable and cost‐effective ORR catalysts are needed. In recent years, zeolitic imidazolate framework (ZIF) derived carbon materials emerge as a new class of non‐precious metal catalysts (NPMCs) toward ORR, largely benefiting from their high surface area, abundant porosity, tunable chemical/electronic structure, and superior ORR activity which is comparable or even surpasses those state‐of‐the‐art Pt‐based ORR catalysts. This review offers a comprehensive overview of the recent advances in ZIF‐derived carbons for ORR. The synthesis strategies and the key factors affecting the ORR performance of ZIF‐derived carbon materials are discussed. Future research directions and perspectives on exploring ZIF derived carbons as efficient ORR catalysts are highlighted, with a focus on the principles of rationally engineering the coordination structures of active sites. [ABSTRACT FROM AUTHOR]

Efficient electron transfer from photosensitizer to catalytic sites is crucial for effective artificial photosynthesis, yet it remains a significant challenge. Herein, it is reported that simple fluorination of the organic linkers in the MIL‐101(Fe) photocatalyst results in a remarkable threefold increase in the photocatalytic CO2‐to‐CO conversion rate (688 µmol g−1 h−1) compared to the pristine counterpart (230 µmol g−1 h−1). It is unveiled that, instead of directly modifying the electron structure of MIL‐101(Fe), the fluorinated linkers enhance the interaction between the discrete photocatalyst and photosensitizer ([Ru(bpy)3]2+, bpy = 2,2'‐bipyridine) via hydrogen bonding, thereby facilitating their intermolecular electron transfer. Most importantly, it is also demonstrated that this performance boosting strategy can be applied to other Fe‐based metal–organic frameworks (MOFs) photocatalysts such as MIL‐53(Fe) and MIL‐88(Fe). The present work not only underscores the fluorination of organic linkers as a generic promising approach to enhance the photocatalytic performance of MOF‐based catalysts, but also holds significant implications for photosynthesis and catalytic processes reliant on intermolecular electron transfer as an important step. [ABSTRACT FROM AUTHOR]

Paper‐based microfluidics emerges as an innovative platform for constructing miniaturized electrochemical devices, which mainly benefit from the spontaneous capillary action of paper. Nevertheless, the capillary‐driven flow dynamics on paper are determined exclusively by the intrinsic properties of paper and fluidics, thus lacking the controllability that conventional pump‐based microfluidics can provide. Herein, an approach to regulating the capillary flow on paper is introduced by conjugating the outlets of microfluidic channels with a photothermal module for water evaporation. The capillary flow rate on paper can be handily regulated from 4 to 37 µL min−1 under controllable illumination conditions. As a proof‐of‐concept, prototypical paper‐based microfluidic fuel cells integrated with the photothermal module are constructed. Their peak power density can be boosted from 0.3 up to 2.1 mW cm−2 under the simulated sunlight irradiation. The influence of capillary flow rate on the fuel cell performance is further validated using multiphysics simulations. The present work not only provides a practically feasible method to boost the performance of paper‐based microfluidic fuel cells using solar energy, but also opens a new avenue for modulating the performance of paper‐based microfluidics, which has long been a challenge in this field. [ABSTRACT FROM AUTHOR]

The key to fully leveraging the potential of the electrochemical CO2 reduction reaction (CO2RR) to achieve a sustainable solar‐power‐based economy is the development of high‐performance electrocatalysts. The development process relies heavily on trial and error methods due to poor mechanistic understanding of the reaction. Demonstrated here is that ionic liquids (ILs) can be employed as a chemical trapping agent to probe CO2RR mechanistic pathways. This method is implemented by introducing a small amount of an IL ([BMIm][NTf2]) to a copper foam catalyst, on which a wide range of CO2RR products, including formate, CO, alcohols, and hydrocarbons, can be produced. The IL can selectively suppress the formation of ethylene, ethanol and n‐propanol while having little impact on others. Thus, reaction networks leading to various products can be disentangled. The results shed new light on the mechanistic understanding of the CO2RR, and provide guidelines for modulating the CO2RR properties. Chemical trapping using an IL adds to the toolbox to deduce the mechanistic understanding of electrocatalysis and could be applied to other reactions as well. [ABSTRACT FROM AUTHOR]