Tuning the catalytic performance of CaSnO3 by developing an S-scheme p-n heterojunction through Ag6Si2O7 doping

Perovskites, especially alkaline earth stannates, have drawn enormous interest from the research community owing to their low chemical toxicity, environmental friendliness, excellent optical properties, and good thermal and chemical stabilities. However, poor conductivity, intense carrier recombination, and low absorption in the visible range prevent them from being practical. Herein, we took calcium tin oxide (CaSnO3) as the target material and improved its photocatalytic performance by introducing different ratios of silver silicate (Ag6Si2O7). The constitution of the heterostructure in CaSnO3/Ag6Si2O7 not only improved the separation of carriers but also promoted the absorption in the visible region owing to a reduction in the optical bandgap. The presence of Ag6Si2O7 in the composite catalyst improved the conductivity and thereby helped carriers carry most of the energy to the surface of the catalyst. When the Ag6Si2O7/CaSnO3-H catalyst was tested against RhB degradation, it achieved a degradation efficiency of 95.24% in 60 minutes whilst showing a degradation rate constant of 0.04971 min(-1) which is 24.48 times greater than its counterparts. The quenching experiments showed that holes and OH radicals play a crucial role during the degradation process. The employed catalyst retained excellent recycling ability up to four cycles suggesting its excellent practicality in the field of catalysts. The facile and environmentally sustainable approach used for synthesizing Ag6Si2O7/CaSnO3 hybrids could be of great importance in the field of visible-light-driven catalysts and their subsequent applications.

Automated summary

Perovskites, particularly alkaline earth stannates, have attracted significant interest due to their favorable properties. In this study, the researchers enhanced the photocatalytic performance of calcium tin oxide by incorporating silver silicate. The resulting heterostructure exhibited improved carrier separation and enhanced absorption in the visible light range. The Ag6Si2O7/CaSnO3 catalyst demonstrated high efficiency and recyclability in the degradation of RhB, making it a promising candidate for visible-light-driven catalysts.