S-Scheme Bi 2 S 3 /CdS Nanorod Heterojunction Photocatalysts with Improved Carrier Separation and Redox Capacity for Pollutant Removal

Constructing step scheme (S-scheme) heterojunctions makes it possible for promoting the separation and transfer of photoinduced carriers, as well as maintaining strong photoredox capacities. Herein, S-scheme Bi 2 S 3 /CdS heterojunctions were designed and constructed by the in situ substitution of Bi 3+ on CdS nanorods. The S-scheme 10%-Bi 2 S 3 /CdS heterojunction with intense interfacial contacts shows not only an optimal photoreduction rate toward Cr(VI) (3.18 and 7 times that of pure CdS and Bi 2 S 3, respectively) but also a high photodegradation rate of ciprofloxacin (1.94 and 8.75 times that of pure CdS and Bi 2 S 3, respectively). Meanwhile, the S-scheme 10%-Bi 2 S 3 /CdS heterojunction could efficiently prevent itself from photoetching. It is confirmed that the S-scheme 10%-Bi 2 S 3 /CdS heterojunction is produced by a built-in electric field between CdS and Bi 2 S 3, which not only improves the charge transfer and separation efficiencies but also maintains strong redox capacities. The present study will provide distinguished insight into fabricating an S-scheme heterojunction with strong photoredox capabilities for the removal of pollutants.