A facile method to decompose CO₂ using a g-C₃N₄-assisted DBD plasma reactor

The present study accomplishes the partial reduction of CO₂ to carbon monoxide in a dielectric barrier discharge (DBD) reactor packed with g-C₃N₄ and TiO₂ or ZnO mixed with g-C₃N₄. Typical results indicate that the ZnO + g-C₃N₄ packed reactor provides ~12% CO₂ conversion at SIE of 4.8 J/mL, whereas DBD yields only ~7.5% conversion under the same experimental conditions. The best performance of the ZnO integrated system is due to the presence of more basic sites than those of the TiO₂ packed system, which enables effective adsorption of acidic CO₂ on its surface. The highest energy efficiency of 1.106 mmol/kJ is achieved with 5% ZnO + g-C₃N₄ at SIE of 4.8 J/mL, whereas DBD exhibits only 0.746 mmol/kJ under the same conditions. Notably, catalyst packing also enables the highest carbon balance of ~97%.