Doping TiO2 with sludge-derived activated carbon by UV light irradiation method: Molecular dynamic simulation and experimental study

Abstract

Sludge-derived activated carbon (SDAC) is prepared from sewage sludge and can be used to treat pollutants. SDAC can also be used to dope catalytic materials to improve their pollutant degradation ability. However, there needs to be more research on doping TiO2 with SDAC. In this study, TiO2 was doped with SDAC by Ultraviolet light irradiation method under room temperature. The doping process saved a large amount of energy. The TiO2 doped with SDAC had the ability to degrade dyes under visible light. The results showed that the removal rates of SDAC-doped TiO2 for methyl orange (MO) and methylene blue (MB) were over 90% and 94% under visible light conditions. After five cycles, the removal rate of MO was 75%, while the removal rate of MB decreased to 45%. Molecular dynamics simulation results showed that the valence band and conduction band of SDAC-doped TiO2 shifted downward, and three apparent impurity levels appeared near the Fermi level after SDAC doping.