Efficient interfacial charge transfer: establishing a B–Co electron bridge and heterojunction synergistic enhancement of hydrogen evolution activity between borophene and Co9S8

Abstract

The application of borophene in the field of photocatalytic hydrogen production is a novel attempt. Based on van der Waals interactions, a type II heterojunction is constructed. An electron-directed transfer path B–Co electron bridge is established based on the overlap of the conjugated planes, shortening the transmission path, enhancing the efficiency of the photocarrier separation, accelerating electron transfer at the contact interface, and enhancing hydrogen evolution reaction. The best hydrogen evolution performance of Co₉S₈/borophene is 4271.40 μmol g⁻¹ h⁻¹, which was 63.75 times that of borophene and 5.77 times that of Co₉S₈. The in situ characterization has demonstrated that Co₉S₈/borophene effectively inhibits charge recombination, verifying the direction of electron transfer, and further demonstrating the successful construction of the heterojunction. This paper successfully confirmed the applicability and prospect of layered borophene in the field of photocatalytic hydrogen production. The application of interface engineering has laid the foundation for producing more efficient and scalable photocatalysts.