Synthesis and characterization of N-doped TiO 2/ZrO 2 visible light photocatalysts

Abstract

Zirconia and nitrogen-doped TiO 2 powder was synthesized using a polymer complex solution method for the preparation of an enhanced visible light photocatalyst. The produced catalysts were characterized via the Brunauer, Emmett, and Teller method (BET), X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectra, and UV–Vis spectrophotometry analyses. The N-doped TiO 2/ZrO 2 photocatalyst showed a high specific surface area and small crystal sizes. The XPS spectra of the N-doped TiO 2/ZrO 2 sample indicated that nitrogen was doped into the TiO 2 lattice and enhanced the photocatalytic activity. The UV–Vis absorption spectra of the N-doped TiO 2/ZrO 2 sample noticeably shifted to the visible light region compared to that of the TiO 2. The photocatalytic activities of the prepared catalysts were evaluated for the decomposition of gaseous NO x under UV and visible light irradiations. The photocatalytic activities of N-doped TiO 2/ZrO 2 were much greater than those of commercial Degussa P25 in both the UV and visible light regions. The high photocatalytic activity can be attributed to stronger absorption in the visible light region, a greater specific surface area, smaller crystal sizes, more surface OH groups, and to the effect of N-doping, which resulted in a lower band gap energy.