Heterogeneous ZnS–zinc carbonate hydroxide micro-belts for Cr(vi) reduction under simulated sunlight

Abstract

Heterogeneous ZnS–zinc carbonate hydroxide (ZnS–ZCH) micro-belts were facilely synthesized and the composite belts displayed a dramatic enhancement in response to simulated sunlight as indicated by more than seventy- and four-fold increase in the Cr(VI) photo-reduction rate compared with those of ZCH and commercial titanium dioxide (Degusa P25), respectively. The structure, composition and optical properties were investigated by a series of methods and the results indicated an enhanced separation of holes and electrons as well as a decrease in the band gap due to the existence of ZnS. The promoted photo-activity could be ascribed to the high utilization of light due to the existence of ZnS with small particles, high dispersion in the composite and porous structure.