Photocatalysis Performance of Nb-doped TiO2 Film in Situ Growth Prepared by a Micro Plasma Method

Abstract Thin TiO 2 films in-situ grown on titanium alloy substrate were prepared in 0.05 mol/L H 2 SO 4 electrolyte using the micro plasma oxidation method. The photocatalytic properties of the prepared thin TiO 2 films were investigated using Rhodamine B solution as a target pollutant. In order to improve the photocatalytic properties of the obtained TiO 2 films, different contents of Nb(NO 3 ) 3 were added into the H 2 SO 4 electrolyte and the Nb-doped TiO 2 films in situ growth were obtained. The influences of the doping ions on the surface morphologies, the crystal phase compositions and microstructures of the TiO 2 films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results show that doping of Nb ions can refine the mesoporous TiO 2 grain and increase the specific surface area. But doping of Nb ions has little influence on the crystal phase composition and the lattice parameters. Otherwise, doping of Nb ions can improve the photocatalytic activity of TiO 2 thin films, when the Nb(NO 3 ) 3 is 1.2 g/L, the degradation rate of Rhodamine B solution in 90 min reaches 85%, showing the strongest light degradation ability.