S-scheme SnO/TiO2 heterojunction with high hole mobility for boosting photocatalytic degradation of gaseous benzene

Enhancing the efficiency of carrier migration and separation plays a pivotal role in promoting photocatalytic performance. Constructing S-scheme heterojunction is a promising strategy to achieve this desired objective. Here, we rationally designed and preciously synthesized SnO{0 0 1}/TiO2{0 0 1} S-scheme heterojunction with exceptionally high hole mobility (1122 cm2/(V·s)), which ranks among the best of reported works. SnO{0 0 1}/TiO2{0 0 1} heterojunctions exhibited outstanding performance of gaseous benzene degrading. The degradation rate constant of SnO/TiO2 heterojunction is 2.4675 h−1, and is boosted by 5.3 times compared with TiO2 (0.4595 h−1). Through the combination of theoretical calculation and experiment, S-scheme mode of carrier transferring was verified. The promoted hole mobility in SnO/TiO2 heterojunction enhances the production of ·OH, further boosting photocatalytic performance. By analyzing the detected intermediates, we proposed degradation pathways for benzene, which provide a profound and elucidating view of complex processes in benzene photocatalytic degradation.