Synthesis Of F, N Co-doped TiO₂ Decorated Graphene And The Study Of Photocatalytic Activity

Firstly, the graphene oxide(GO) is prepared with graphite as raw materials by the modified Hummers method, then F and N co-doped P25 decorated graphene oxide composite catalyst(F-N-P25/rGO) was successfully prepared by a facile one-step hydrothermal method utilizing GO, P25, urea, NH4F and Vc as precursors. The process parameters shuc as the reaction time, the ratio of fluorine to Ti (mol), the dosage of GO and the surfactant had been optimized. The optimum prepared conditions were that the ratio of fluoride to titanium is 1:1, the dosage of graphene is 5%, hydrothermal temperature is 180℃ and time is 16 h. The degradation rate of MO was 100% under UV light irradiation for 80 min and 28.6% under visbile light irradiation for 4h. The degradation rate of MO under visbile light has increased 2 times compared with commercial P25.Similarly, the F and N co-doped TiO2 decorated graphene oxide composite catalyst (F-N-TiO2/rGO) was successfully prepared utilizing commercial TiO2, as precursor. The composition, morphology, spectral properties and structure of thecomposite photocatalyst were characterized by XRD, HRTEM, RAMAN, XPS, UV-Vis DRS. The results show that F and N co-doped TiO2 particles with anatase phase were well-dispersed on the surface of the reduced graphene oxide sheets. The absorption edge of F-N-TiO2/rGO shifts to the visible light range and the optical absorption shows enhancement in the visible light region from 400 nm to 800 nm. The degradation rate of methyl orange on F-N-TiO2/rGOcomposite is 1.17mg·h-1·g-1 under visible light, which has increased 2.8 times compared with commercial P25. It is attributed to the interaction between TiO2 and graphene via C-Ti covalent bonds, which promotes the efficient separation of photogenerated charges resulting from the improved electrical conductivity of the rGO sheets...