H2S Involved Photocatalytic System: A Novel Syngas Production Strategy by Boosting the Photoreduction of CO2 While Recovering Hydrogen from the Environmental Toxicant

Abstract

AbstractSimultaneous treatment of CO2 and H2S by photocatalytic technology is of great significance in mitigating the greenhouse effect and environmental hazards, while producing valuable solar fuels at the same time. In this study, well‐defined CdS/TiO2:Cu hollow spheres with highly dispersed heterointerfaces are successfully constructed for photoreduction of CO2 in presence of in situ generated H2S. Benefiting from the consumption of photo‐generated holes (h+) and large production of protons by H2S decomposition, the generation rates of CO (781.3 µmol·g−1∙h−1, accounting for 94.9 v/v% of CO2 reduction products) and H2 (5875.1 µmol·g−1∙h−1) increased significantly, which are 1.4 and 68.9 times higher than that of the system without H2S, respectively. Moreover, the remediation of photocorroded CdS by H2S prolonged the service life of the heterojunction, and maintained a CO generation rate of 96.8% after 4 cycles with or without H2S. Notably, as a potential syngas production strategy, by adjusting the initial concentration of Na2S, the ratio of CO and H2 is controlled from 1.07 to 7.21 to fulfill the demands of different chemical synthesis. This strategy opens up a new horizon for the combination of energy photocatalysis and environmental photocatalysis, which has great research and application prospects.