Reinforced photogenerated electron convergence on graphdiyne(g-CnH2n-2) “as an active site and substrate” for enhance photocatalytic hydrogen production

Abstract

Graphdiyne(GDY), as a carbon-based catalyst with tunable electronic structure, has a significant impact on the advancement of sustainable photocatalytic technology. Its tunable electronic structure can effectively regulate the activity and selectivity of photocatalytic reaction. In this paper, GDY was prepared by a new method of ball milling HEB-TMS, and CoWO4 nanoparticles were uniformly loaded on the surface of GDY to construct a Type-II heterojunction. GDY provides a dispersed and effective substrate for CoWO4, forming a closer contact interface. Based on GDY's unique electronic structure and the formation of Type-II heterojunction, GDY/CoWO4 enhances the separation of photoexcited electrons and holes, thus increasing the electron cloud density on GDY. As an electron acceptor and active site for hydrogen production, GDY promotes the proton reduction reaction. In addition, the charge transfer process of GDY/CW-15 was demonstrated by in-situ XPS and UPS, and the corresponding hydrogen production mechanism was proposed. This study provides a facile and efficient method for preparing GDY and a new idea for heterojunction photocatalyst based on GDY substrate.