Revealing DeNOx and DeVOC Reactions via the Study of the Surface and Bandstructure of ZnSn(OH)6 Photocatalysts

Abstract Photocatalytic materials present a robust approach in tackling pollutants in the air. However, the involving reactions and their associated toxicity, those are important for practical implications, have not been sufficiently reported. Here, we synthesize ZnSn(OH)6 and control its morphology by changing NaOH's dosage in a one-step hydrothermal growth. Combining results from density functional theory and experimentation, we initiatively show the roles of exposed facets, oxygen defects, metal terminated surface, and bandstructure of ZnSn(OH)6. By carefully characterizing reactions during DeNOx and DeVOC processes, this work enables a comprehensive understanding of photocatalytic activity against pollution of nitric oxide and VOCs. Also, a new systematic calculation of the apparent DeNOx index is introduced for evaluating the total toxicity. The trapping experiments reveal a balance in the involvement of e–, h+, •OH radicals in the photocatalytic DeNOx and DeVOC. Thus, our findings would enable an important understanding of addressing air pollution using high-performance photocatalysts and proper evaluation of total toxicity.