Abstract:The N-TiO2 intermediate was prepared by sol-gel method using butyl titanate and urea as titanium source and nitrogen source, respectively. The N-TiO2 intermediate were treated by N2 atmospheric calcination, “N2 plasma treatment + N2 atmospheric calcination” and “N2 atmospheric calcination + N2 plasma treatment”, which were noted as N-TiO2(C)、N-TiO2(LTP+C) and N-TiO2(C+LTP), respectively. The samples were evaluated under visible light irradiation for photocatalytic degradation of methyl orange (MO). To elucidate the plasma effect, XRD, TEM, EDS, UV-vis DRS and XPS techniques were used for catalyst characterization. Compared to N-TiO2(C), N-TiO2 treated by N2 plasma had smaller particle size, more responsive to visible light, and higher N content. Within 240 min of visible light irradiation, the photodegradation performance of N-TiO2 to MO was decreased in the sequence of N-TiO2(LTP+C)>N-TiO2(C+LTP)>N-TiO2(C), and the maximum degradation rate of N-TiO2(LTP+C) was 90%. The photodegradation performaces of three kinds of N-TiO2 on MO were consistent with the pseudo first-order kinetic equation.And the apparent rate constants of N-TiO2(LTP+C) and N-TiO2(C+LTP) were 4.5 times and 1.9 times that of N-TiO2, respectively. It was indicatded that the introduction of N2 plasma treatment in the preparation of N-TiO2 was beneficial to improve the surface dispersibility of N element, increase the incorporation of N element, and enhance the visible light photocatalytic activity of N-TiO2.“N2 plasma treatment + N2 atmospheric calcination” was the best method to prepare N-TiO2 visible photocatalysts.
