Immobilization of visible light-sensitive (N, Cu) co-doped TiO2 onto rectorite for photocatalytic degradation of p-chlorophenol in aqueous solution

To further enhance the photocatalytic properties of doped-TiO2, a series of (N, Cu) co-doped TiO2/rectorite composites with different amount of N doping were prepared for adsorption and catalytic oxidation of p-chlorophenol (p-CP) under visible light. The physicochemical properties of the obtained composites were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), etc. The results showed that the (N, Cu) co-doped TiO2 catalyst was immobilized well onto rectorite, and the doping of N and Cu could affect the crystal structure of TiO2. The optimal N doping amount was determined by the photocatalytic degradation of p-CP in a stirred quartz reactor under visible light (>420 nm) irradiation. It was found that the doping of N can improve significantly the degradation of p-CP and the optimum N doping amount is 1.0%. The adsorption of p-CP by the composites could accelerate the degradation rate of p-CP in situ. The photocatalytic activity of the (N, Cu) co-doped TiO2/rectorite composites remained stable after five cycles of photoreaction. A possible mechanism for the photocatalytic degradation of p-CP is proposed. Our work implied that rectorite has great potential to be applied in the field of photocatalysis. (C) 2016 Elsevier B.V. All rights reserved.