Preparation of visible light responsive N doped TiO2 via a reduction–nitridation procedure by nonthermal plasma treatment

Abstract A visible light responsive N-doped TiO 2 was prepared via a reduction–nitridation procedure by nonthermal plasma treatment. X-ray diffraction, N 2 adsorption, UV–vis spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy were used to characterize the prepared TiO 2 samples. The plasma treatment did not change the phase composition and particle sizes of TiO 2 samples, but extended its absorption edges to the visible light region. The photocatalytic activities were tested in the degradation of an aqueous solution of a reactive dyestuff, methylene blue, under visible light. The photocatalytic activities of TiO 2 prepared by reduction–nitridation procedure were much higher than that of samples prepared by simple nitridation treatment. The enhanced activity was ascribed to the substitutional N-doping and appropriate concentration of oxygen vacancies. TOHN10 prepared by reduction–nitridation procedure exhibited excellent photocatalytic stability. A possible mechanism for the photocatalysis was proposed.