ZnO nanowire arrays decorated 3D N-doped reduced graphene oxide nanotube framework for enhanced photocatalytic CO2 reduction performance

Photocatalytic CO2 reduction is considered as a potential route to solve the increasing energy crisis and greenhouse effect. However, CO2 activation is still a big challenge because of the formidable electron transfer to CO2. Herein, an effective strategy was developed to facilitate CO2 activation and reduction by in situ growth of ZnO nanowire arrays (ZnO NWAs) on the electronic-rich surface of three-dimensional (3D) N-doped reduced graphene oxide (N-rGO). Thanks to the positive effects of 3D N-rGO, ZnO/N-rGO exhibits a significantly enhanced photocatalytic CO2 reduction to CH3OH performance (CH3OH-production rate of 1.51 mu mol h(-1) g(-1)), which was ca. 2.3 and 4.7 times higher than that of the pristine ZnO and commercial ZnO, respectively. It is found that 3D N-rGO can work as a trifunctional co-catalyst to support the uniform growth of ZnO NWAs, effectively improve the separation of electron-hole pairs and act as CO2 adsorption and reduction active sites. This work exhibits a facile method to prepare 3D N-rGO-based composite materials, and also demonstrates that N-rGO is a promising multifunctional co-catalyst for photoreduction of CO2.

Automated summary

The study developed an effective strategy to facilitate CO2 activation and reduction by in situ growth of ZnO nanowire arrays on the electronic-rich surface of N-doped reduced graphene oxide. The composite material showed significantly enhanced photocatalytic CO2 reduction to CH3OH performance, with 3D N-rGO acting as a trifunctional co-catalyst supporting the growth of ZnO NWAs, improving electron-hole pair separation, and serving as CO2 adsorption and reduction active sites. This work demonstrates a promising multifunctional co-catalyst for the photoreduction of CO2.