Synergetic effects of nitrogen doping and Au loading on enhancing the visible-light photocatalytic activity of nano-TiO2

Nitrogen-doped together with gold-loaded TiO2 (Au/N–TiO2) nanoparticles were prepared by a simple wet-chemical method. The samples were characterized by XRD, TEM, XPS, UV–vis diffuse reflectance spectroscopy, and photoluminescence (PL) spectroscopy. It reveals that Au was loaded on the surface of TiO2 in the form of metallic Au, and nitrogen is introduced into TiO2 matrix in the form of substitutional nitrogen and interstitial nitrogen. Au/N–TiO2 exhibits much higher visible-light photocatalytic activity when compared with single N-doped or Au-loaded TiO2. A synergetic effect was proposed to explain the effects of nitrogen doping and Au loading on enhancing the visible-light photocatalytic activity of TiO2.