Highly efficient photocatalytic formic acid decomposition to syngas under visible light using CdS nanorods integrated with crystalline W2N3 nanosheets

Abstract

Syngas (H₂/CO) production by photocatalytic formic acid decomposition is a promising method for solar energy conversion. Furthermore, syngas can be used as a fuel in internal combustion engines and can also be converted to other liquid fuels as well as high-value chemicals. In this study, an efficient photocatalytic system was constructed by combining crystalline W₂N₃ nanosheets and CdS nanorods for formic acid decomposition to syngas with an adjustable ratio. Under visible light illumination, the optimal rate of H₂ production is 262 μmol h⁻¹ with 207 μmol h⁻¹ for CO generation, which are among the highest values achieved from photocatalytic syngas production. Meanwhile, the apparent quantum yields of H₂ and CO evolution are 17.6% and 16.9%, respectively. Further experimental results demonstrate that the heterostructures formed between CdS and W₂N₃ can effectively facilitate interfacial charge transfer and separation. This work also provides insight into developing a novel and low-cost approach for renewable energy conversion.