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High-efficiency hydrogen production using nonprecious electrocatalysts is considered a feasible solution for solving energy and environmental crises. Herein, we first develop a novel, simple, rapid, and environmentally friendly plasma-induced transformation approach to in situ engineer MOF-derived heterointerface catalyst. The plasma engineered MOF-derived Co4N–Co3O4–C has a well-defined interface structure and exhibits remarkable electrocatalytic performance for alkaline hydrogen evolution with a very low overpotential of 46 mV at 10 mA cm−2. Theory calculation verifies that the formation of heterointerface induces electron redistribution mainly in the interface region, particularly to the side of Co4N, triggering interface Co as active sites, in which there is stronger water capture capability, decreasing the energetic barrier of water dissociation, and optimal hydrogen absorption. This work presents a feasible and ingenious strategy to design and synthesize diverse electrocatalysts with MOF-derived heterointerface. [ABSTRACT FROM AUTHOR]

The electrocatalytic nitrogen reduction reaction (e-NRR), an eco-friendly and economical approach to convert nitrogen to ammonia under mild conditions, has received widespread attention in recent years. Defect engineering has been illustrated to be an effective strategy to improve the catalytic activity and selectivity of electrocatalysts via changing the electronic states as well as creating additional active sites for reduction reactions. Thus far, various approaches have been adopted to tune the physical and chemical properties of catalyst materials by means of inducing defects of different types and varying their concentrations or locations in host materials. In this review, the mechanisms and design principles of defective electrocatalysts for the NRR are introduced, and the refined synthesis and characterization techniques of defect engineering are systematically summarized. Based on the recent advances in defect engineering of electrocatalysts for the NRR, the roles of various defect states, such as vacancies and the amorphous phase, in the catalytic enhancement mechanism are comprehensively discussed. Finally, perspectives on the challenges and opportunities in developing new cost-effective and high-efficiency NRR catalysts for practical applications are outlined. [ABSTRACT FROM AUTHOR]