Augmenting reactive species over MgIn2S4-In2O3 hybrid nanofibers for efficient photocatalytic antibacterial activity

Narrow bandgap semiconductor MgIn 2 S 4 has been readily grown onto In 2 O 3 nanofibers by an in situ growing method. The so-formed MgIn 2 S 4 -In 2 O 3 hybrid nanofibers are characterized by strong visible light absorption and intimate MgIn 2 S 4 /In 2 O 3 heterointerfaces. Under visible light illumination ( λ ≥ 400 nm), the hybrid nanofibers demonstrate an exceptionally high photocatalytic activity for Escherichia coli ( E. coli ) disinfection, outcompeting pristine MgIn 2 S 4 , naked In 2 O 3 nanofibers, and many other photocatalytic systems reported. Specifically, the hybrid nanofibers achieve a 7 log reduction in viable cells for merely 20 min illumination while pristine MgIn 2 S 4 and naked In 2 O 3 nanofibers alone are almost inactive. Further analysis indicates that the hybrid nanofibers essentially form a type-II semiconductor heterojunctions which enable spatial separation of photocarriers. Owing to the intimate heterointerfaces, photocarriers can be promptly separated and accumulated respectively in In 2 O 3 and MgIn 2 S 4 thereby allowing continuous generation of copious reactive species for disinfection. This work signifies the usefulness of heterointerfaces in promoting photocarrier separation and provides a useful strategy to upgrade photocatalytic performance from otherwise almost inactive semiconductors.