Efficient benzaldehyde photosynthesis coupling photocatalytic hydrogen evolution

Photosynthesis of organic compounds in coupling with promoted hydrogen evolution under mild condi-tions of light irradiation is considered as one of the most efficient and promising approach to obtain high purity hydrogen and value-added chemicals concurrently by utilizing green solar energy. Here, we report the synthesis of NiS nanoparticle-modified CdS nanorod composites (NiS/CdS) as an efficient bifunctional catalyst for the highly selective photocatalytic synthesis of high-value-added product benzaldehyde (BAD) from aqueous solution of benzyl alcohol (BA) under oxygen-free conditions, in accompanying with the efficient hydrogen evolution. The synergetic catalytic effect between NiS and CdS is proposed to play an important role in elevating the photo-redox performance. The composition-optimized 30% NiS/CdS catalyst affords an extraordinarily high H2 generation rate of 207.8 lmol h-1 and a simultaneous BAD generation rate of 163.8 lmol h-1 under visible light irradiation, which are respectively 139 and 950 times higher than those of CdS without NiS modification. To our knowledge, these are the highest pho-tocatalytic production rates of both H2 and aldehyde ever reported on the concurrent photocatalytic of aldehyde synthesis and hydrogen evolution in green aqueous solution. This work provides a highly effi-cient photosynthesis strategy for the concurrent productions of high-value-added fine chemicals and hydrogen. (c) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.