S–Cu–FC/CuS modified GO carboxymethyl cellulose hydrogel for enhanced photocatalytic sterilization through homo-heterojunction interface accelerated charge transfer

Charge transfer and separation play a critical role in the photocatalytic efficiency of photoresponsive materials and their subsequent applications. Herein, for the first time, we constructed a homo-heterostructured S–Cu–FC/CuS modified carboxymethyl cellulose (CMC) hydrogel doped with graphene oxide (GO) (S–Cu–FC/CuS/GO@CMC) through an in situ ionic complexation reaction, which exhibited enhanced photocatalytic performance under 808 nm near-infrared (NIR) light irradiation. On the one hand, photo-excited charges can rapidly transfer across the homo-heterojunction interface with copper atoms in S–Cu–FC/CuS as both donors and acceptors. On the other hand, the interface between GO and S–Cu–FC/CuS also favors the fast transfer of photogenerated charges. Hence, with the assistance of a photothermal effect, the enhanced photocatalytic performance of S–Cu–FC/CuS/GO endowed the hydrogel with robust sterilization ability for killing 99.5% S. aureus and 100.0% E. coli under 10 min NIR light irradiation. An in vivo test disclosed that this hydrogel could also accelerate the healing of bacteria-infected wounds.