Efficient reduction of CO2 to C2 hydrocarbons by tandem nonthermal plasma and photocatalysis

CO2 photoreduction to hydrocarbons is a carbon-neutral technology for renewable energy. However, this strategy is challenged by the thermodynamic stability of CO2 and the low efficiency of multi-photoelectron utilization. In this paper, tandem nonthermal plasma and photocatalysis were used to effectively improve the efficiency of CO2 reduction to C-2. We first activated CO2 by nonthermal plasma technology (NTP) and then converted the activated CO2 into C-2 products by Cd0.8Zn0.2S/In2O3 photocatalyst with a special nanostructure. Without the addition of any sacrificial agent, the C-2 yield of the catalyst reached 0.382 mu mol h(-1), which is one of the highest performances to date. In situ experimental and computational studies show that CO2+ activated by NTP has higher pi orbital and HUMO levels of lone pair electrons and promotes the reduction of CO2+ by injecting electrons into the vacant orbital of the active site of Zn. At the same time, the unique structure of Cd0.8Zn0.2S/In2O3 photocatalyst can extend the life of charge through the optical field enhancement effect, and then react with the CO2+ intermediates generated by NTP technology to promote the coupling of C-C bonds, and finally promote the photocatalytic multi-electron reaction to produce C-2 hydrocarbons.