Constructing ZnSn(OH)6/SrSn(OH)6 perovskite-structured hydroxide heterojunction to enhance photocatalytic degradation of toluene

A ZnSn(OH)6/SrSn(OH)6 perovskite-structured hydroxide heterojunction was constructed by a simple one-pot hydrothermal method and applied to degrade toluene under UV light. The optimal sample 20% ZnSn(OH)6/SrSn(OH)6 heterojunction (named 20% ZSH/SSH) exhibits a toluene degradation rate of 86.55%, which is 26.34% and 20.13% higher than that of SrSn(OH)6 and ZnSn(OH)6 for 30 min, respectively. The ESR shows that ·OH and ·O2− generated in the SrSn(OH)6/ZnSn(OH)6 system acted as the main reactive radical to induce the degradation of toluene. Moreover, the degradation process of toluene was also investigated by In-situ DRIFTS, which demonstrates a pathway that ZnSn(OH)6/SrSn(OH)6 could promote the conversion of toluene to benzyl alcohol, benzaldehyde, benzoic acid, and then mineralized to H2O and CO2. This work offers a promising approach for building perovskite-structured hydroxide heterojunction by a simple one-pot hydrothermal method to improve photocatalytic performance for reducing indoor air contamination.