Plasmon‐Enhanced Electrocatalytic Oxygen Evolution Reaction by Au Nanoparticles‐Supported Borophene Nanosheets

Abstract Designing efficient and stable electrocatalysts for the oxygen evolution reaction (OER) is essential for sustainable water splitting to produce hydrogen, and their activity can be further enhanced by applying an external field, such as light. Recently, borophene‐based nanostructures have shown great potential in catalyzing OER due to their distinct set of exciting physical and chemical characteristics. In this study, a heterostructure was constructed by decorating Au nanoparticles on borophene (Au@B), and the electrocatalytic performance was examined. Borophene suppressed the agglomeration of Au nanoparticles, whereas electronic regulation between them stabilized the electron deficiency of borophene. Also, this electron transfer from Au to borophene generated abundant OER‐active Au δ+ sites, and the conductive borophene enabled efficient electron delocalization. Au@B required overpotentials of 270 and 299 mV to attain 10 and 50 mA cm −2 , respectively. These results were accompanied by faster kinetics, low charge transfer resistance, a large OER active surface area, and excellent stability. Moreover, Au@B exhibited plasmonic properties under visible light, and borophene facilitated effective separation of hot charge carriers, enhancing the built‐in polarization and further boosting the OER activity. This work will encourage designing and investigating borophene‐based heterostructures with plasmon‐assisted catalytic activity for various electrochemical reactions.