Enhanced CO2 conversion via synergistic effect of dielectric barrier discharge plasma and halogen-modified g-C3N4.

Carbon dioxide (CO2) conversion is a key challenge in addressing global warming and the associated climate change. Non-thermal plasma activation of CO2 is a viable alternative to traditional thermal catalytic routes for converting CO2 into CO and O2. In this study, a dielectric barrier discharge (DBD) plasma reactor operated under ambient conditions was developed and demonstrated for CO2 conversion to CO. The integration of halogen-modified g-C3N4 markedly enhanced CO2 conversion relative to the unpacked condition. The addition of a photocatalyst to the plasma reactor improved plasma discharge parameters, and the synergy present between the catalyst and plasma reactor promoted the conversion. The maximum conversion of CO2 attained was approximately 11% with Br/g-C3N4 at an applied voltage of 22 kV. Additionally, halogen doping enhanced CO selectivity and energy efficiency. Furthermore, the integration of the photocatalyst with DBD avoids coke formation, which is one of the limiting steps in high temperature CO2 activation.