Ag2O/TiO2 nanorods heterojunctions as a strong visible-light photocatalyst for phenol treatment

Ag2O/TiO2 nanorods heterojunctions were synthesized by an environmentally benign approach, including hydrothermal treating TiCl4 aqueous solution for the formation of rutile TiO2 nanorods and precipitating Ag2O quantum dots on the surface of rutile TiO2 nanorods. The as-obtained Ag2O quantum dots were highly uniformly deposited on the surface of rutile TiO2 rods for the formation Ag2O/TiO2 heterojunctions photocatalyst. Such photocatalyst was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N-2 adsorption desorption, UV-Vis diffuse reflectance spectroscopy. The photocatalytic activities of the samples were evaluated by phenol under visible-light irradiation. It was found that the optimal Ag:Ti molar ratio (4:10) contributed the highest photocatalytic performance for removing phenol (10 mg/L) with a degradation rate of 66 %, about 11 and 5 times of that of the pure rutile TiO2 nanorods and N-doped TiO2, respectively, after 40 min of reaction under visible light irradiation (lambda > 420 nm). Such greatly enhanced photocatalytic performance of the as-prepared photocatalysts was attributed to the strong Ag2O/TiO2 heterojunctions, 1D rutile TiO2 architecture, and high visible light absorption capability.