Ultrasonic spray pyrolysis synthesis and visible light activity of carbon-doped Ti 0.91Zr 0.09O 2 solid solution photocatalysts

Abstract

Visible light active carbon-doped Ti 0.91Zr 0.09O 2 solid solution photocatalysts were directly obtained by ultrasonic spray pyrolysis of an aqueous solution containing TiCl 4, ZrOCl 2·8H 2O and CH 3(CH 2) 17NH 2. The samples were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy and infrared spectroscopy. The characterizations revealed the spherical structures of the resulting samples and the substitution of Ti 4+ by Zr 4+ ions and carbon in the TiO 2 lattice. Meanwhile, partial carbon and zirconium existed in the form of carbonate and zirconia, respectively. Moreover, the pyrolysis temperature had significant effect on the amount of dopants substituted in the resulting samples. The carbon doping successfully extended the absorption edges of the solid solution to visible light region. We evaluated photocatalytic activities of the doped solid solution photocatalysts on degradation of rhodamine B in aqueous solutions under visible light irradiation ( λ ≥ 420 nm). It was found that the carbon-doped solid solution photocatalysts exhibited enhanced photocatalytic activity under visible light irradiation comparing to the undoped counterpart. On the basis of characterization results, we attributed the enhanced visible light activity to the carbonate species in solid solution photocatalysts. This study provides a way to synthesize visible light active solid solution photocatalysts on a large scale.