In2S3/Cd0.9Zn0.1S Heterojunction for Efficient Photocatalytic Formic Acid Decomposition to Syngas (H2 + CO) under Visible Light

Photocatalytic decomposition of formic acid (FA) to syngas (H2 + CO) is a valuable sustainable energy conversion strategy. In this study, we combine In2S3 nanoparticles with Cd0.9Zn0.1S nanorods (In2S3/CZS) to construct heterojunctions for directly converting formic acid to syngas under visible light (λ > 420 nm) irradiation. The In2S3/CZS composite was facilely synthesized by a hydrothermal reaction. In2S3/CZS showed excellent photocatalytic activity for FA decomposition. The optimal generation rates of H2 and CO can reach 200 and 204 μmol·h–1, respectively, which is one of the best performances in the photocatalytic decomposition of formic acid for synthesizing syngas. Under irradiation with 420 nm monochromatic light, H2 and CO exhibit apparent quantum yields of 9.7% and 10.6%, respectively. The test date confirms the formation of a type II heterojunction between Cd0.9Zn0.1S nanorods and In2S3 nanoparticles. It can effectively promote the transport and separation of the interfacial charges. This work also provides insight into the development of an efficient photocatalytic system for syngas production.