Type-II CoMoO4/Graphdiyne heterojunction promotes visible-light-driven photocatalytic hydrogen production activity

Abstract

Photocatalytic hydrogen production technology has great challenges in designing and synthesizing stable photocatalyst and inhibiting high recombination rate of carriers. In this paper, CoMoO4/GDY type-II heterojunctions were successfully constructed by coupling a new two-dimensional layered carbon material graphdiyne (GDY) with molybdate (CoMoO4), and the positive effect of GDY on photocatalytic hydrogen production system was studied. The introduction of GDY provides a large number of reaction sites for the reaction. Moreover, due to the strong light absorption and excellent electrical conductivity of GDY, the photoelectrochemical properties of molybdate (CoMoO4) are enhanced. The construction of type-II heterojunctions effectively promotes the spatial separation of photogenerated electrons and holes. The electron transfer mechanism of the photocatalyst was verified based on DFT and in-situ irradiation X-ray photoelectron spectroscopy. The experimental results show that the photocatalytic performance of CoMoO4/GDY photocatalyst is the best (121 μmol), which is 2 times and 45 times that of CoMoO4 and GDY, respectively. This study provides a unique idea for the application of GDY in the field of photocatalysis.