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.