Construction of an efficient synergistic catalytic system using DBD plasma and Fe-TiO₂-rGO/HCP catalytic coating for...

An efficient synergistic catalytic system was constructed by combining a Fe-rGO-TiO₂ coating on honeycomb ceramic plates (HCP) with dielectric barrier discharge (DBD) plasma. The catalyst coating was comprehensively characterized, and its structural and morphological characteristics, chemical bond state, optical properties, and catalytic activity were systematically analyzed. The results show that by doping TiO₂ with Fe and graphene, the catalytic performance of TiO₂ can be enhanced by refining its grains and increasing the specific surface area. Ofloxacin (OFLX) was the target pollutant to evaluate the catalytic activity. The effects of initial pH, electrolyte concentration, and current density on OFLX degradation were analyzed. Compared with the single DBD plasma system, the catalytic ability of the constructed synergistic catalytic system was significantly improved. Under the optimal initial conditions, the Fe-rGO-TiO₂-DBD synergistic system achieved a 99.98 % OFLX degradation rate and enhanced energy output after 60 min of reaction. The measurements of liquid H₂O₂ and O₃ in the system and free-radical scavenging experiments proved that the synergistic method can increase the production of active substances. LC-MS analysis and theoretical calculations were used to propose possible OFLX degradation pathways and identify intermediates. Comprehensive toxicity analysis showed that intermediate products exhibited progressively lower toxicity. Finally, the comprehensive mechanism of DBD synergistic Fe-rGO-TiO₂ catalytic degradation of OFLX was summarized.