ZnO rod/reduced graphene oxide sensitized by α-Fe2O3 nanoparticles for effective visible-light photoreduction of CO2.

ZnO as a potential semiconductor photocatalyst is applied in photoelectrochemistry, photodegradation and photocatalytic hydrogen evolution. However, the lack of visible light absorption and unsatisfactory photocatalytic activity restrict the potential applications of ZnO. In the study, a novel in-situ electrochemical growth strategy was developed to construct α-Fe2O3-ZnO rod/reduced graphene oxide (rGO) heterostructure for extending visible-light absorption ability and improving the photoexcited carrier transport process. The electrochemical growth strategy can also be used to design other heterostructure photocatalytic materials. The α-Fe2O3-ZnO/rGO heterostructure can not only exhibit enhanced photoelectrochemical performance but can also effectively capture CO2 and reduce CO2 to CH3OH under visible light. The interface coordination effect between ZnO and α-Fe2O3 are considerably enhanced via a heterojunction constructed at the interface region. The heterostructure might be applied in the photoelectrochemical water splitting and artificial photosynthesis. The electrochemical growth strategy can be also used to design other heterostructure photocatalytic materials.