In-situ growth of Z-Scheme Ag/PPy/BiVO4 core–shell structure for efficient CO2 photoreduction into hydrocarbon fuels
Xin Guo, Xiaojie Sun, Zhiyuan Wang, Jiahui Zhang, Zhichang Liu, Yufeng Hu, Yan-Duo Liu
Abstract
Photocatalytic reduction of CO 2 to hydrocarbons (e.g., CH 4 ) or CO under mild conditions, providing a feasible and promising method for the environmental remediation and utilization of carbon resources. However, since CO 2 -to-CO is a two–electron process, and even CO 2 -to-CH 4 is an eight-electron reaction, it is a challenging task to achieve CO 2 activation with an extremely short effective charge lifetime. In this paper, a synergistic effect strategy is used to prepare Ag nanoparticles modified PPy/BiVO 4 Z-Scheme composites for synergizing the charge separation and surface catalytic processes in CO 2 reduction reaction. With the joint efforts of synergy, the optimal photocatalyst achieves an efficient CO 2 reduction yield (5.92 μmol·g −1 ·h −1 ) with an exceptionally high CO selectivity of 85.8% and the corresponding O 2 evolution. Based on the result analysis, it can be clearly proved that the excellent CO 2 reduction performance relies on the Z–Scheme charge transfer mechanism between PPy/BiVO 4 composites interface and the strong catalytic effect of Ag nanoparticles on CO 2 . Furthermore, the detailed processes of deoxygenation and proton acquisition during CO 2 reduction is revealed by in-situ DRIFTS and NAP-XPS. This paper demonstrates a strategy for designing efficient photocatalysts toward reduction of CO 2 to higher value-added chemicals, and highlights the importance of catalysis and charge separation to the synergy of key steps in catalytic reactions.