Effect of photocatalytic reduction of carbon dioxide by N–Zr co-doped nano TiO2. Issue 21 (2nd November 2017)

• Record Type: Journal Article
• Authors: Zhang, Ru; Wang, Li; Kang, Zhuo; Li, Qiang; Pan, Huixian
• Is Part Of: Environmental technology. Volume 38:Issue 21(2017)
• Page Start: 2677
• Page End: 2683
• Publication Date: 2017-11-02
• Subjects: TiO2 -- N/Zr–TiO2 composite catalyst -- CO2 -- photo-catalysis -- methane; Environmental engineering -- Periodicals; Environmental protection -- Periodicals; 628.05
• DOI: 10.1080/09593330.2016.1272642
• Languages: English
• ISSNs: 0959-3330

Abstract

ABSTRACT: Modified sol-gel method was adopted to prepare TiO2, Zr–TiO2 and N/Zr–TiO2 composite catalyst. The as-synthesized photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunner− Emmet− Teller measurement and UV-Vis diffuse reflectance spectroscopy. And the photocatalytic performance toward CO2 reduction was evaluated under ultraviolet light. The catalyst particles were demonstrated in the nanometer level size. When N and Zr are co-doped, on the one hand, Ti 4+ can be replaced by Zr4 +, which leads to lattice distortion and inhibits electron-hole recombination. On the other hand, N enters into TiO2 lattice gap to form O–Ti–N bond structure, and partial Ti 4+ are reduced to Ti 3+ . Compared with pristine TiO2, the specific surface area and the band gap of N/Zr–TiO2 were improved and reduced, respectively. The N and Zr synergistically contribute to the obviously strengthened absorption intensity in visible region, as well as significantly improved photocatalytic activity. In the gas phase reactor, when the calcination temperature was 550°C, 0.125N/0.25Zr–TiO2 composite performed the highest photocatalytic activity UV irradiation for 8 h, and the corresponding CH4 yield was 11.837 µmol/g, which was 87.8% higher than that of pristine TiO2 . For the visible light, the CH4 yield was 9.003 µmol/g after 8 h irradiation, which was 83.9% higher than that of pristine TiO2 .