Optimization of Parameters for the Preparation of Au/TiO2 with Photodegradation of NPE-10 in Aqueous Solution

The degradation in aqueous solution of nonionic surfactant, nonylphenyl poly(oxyethylene)ethers (NPE-10), which was photocatalyzed by Au/TiO2 nanoparticles has been studied. The particles were obtained using modified deposition-precipitation with Urea (DP Urea). The Taguchi method was implemented successfully to optimize the photoactivity for Au/TiO2 photocatalyst. The optimized catalyst was characterized by XRD, BET, TEM, XPS and UV-visible absorption spectra techniques. It was found that Au3+/Ti4+ molar ratio was the main parameter having significant effect on photocatalytic activity. Under optimal conditions, the observed Au nano-particle size and distributions indicate, that smaller gold nanoparticles (similar to 1.8 nm diameter) were obtained, and the existing of Au particles promote the photoadsorption of oxygen on the surface of photocatalysts. Both are responsible for the significantly enhanced catalytic activity of commercial TiO2 (pure P-25) toward the photodegradation of NPE-10-probably by increasing the rate of production of separated electrons and holes.