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.