Fluorine lattice-doped ZnS with accompanying sulfur vacancies for high activity and selectivity of CO2 conversion to CO

Photocatalysis CO2 conversion to valuable hydrocarbons driven by solar energy holds great potential in alleviating the greenhouse effect and energy shortage. However, the photocatalytic CO2 reduction activity is hindered by the high charge recombination rate and low CO2 affinity of semiconductor photocatalyst. Herein, a series of fluorine lattice-doped ZnS catalysts with accompanying sulfur vacancies (VS) are prepared via a facile hydrothermal method. Fluorine doped ZnS catalysts exhibit remarkedly enhanced photocatalytic performance for selective CO2 reduction to CO compared to the bulk counterpart, and it is the ZnS0.95F0.05 achieves the highest photoactivity among the as-obtained catalysts. Without cocatalysts or sacrificial reagents, ZnS0.95F0.05 enables CO2 photoreduction to CO with an outstanding yield of 16.04 μmol g−1 h−1 and high selectivity of 84%, about 6 times higher than that of ZnS (2.68 μmol g−1 h−1), surpassing most of the previously reported photocatalysts. The improved activity for fluorine doped ZnS can be due to the promoted carrier separation and CO2 adsorption, owing to the synergistic effect of fluorine doping and concomitant Vs, based on the experimental verification and theoretical calculation. This study offers an effective approach to design photocatalysts for high performance CO2 reduction.