Synthesis and the effect of calcination temperature on the physical–chemical properties and photocatalytic activities of Ni,La codoped SrTiO 3

Abstract

A series of highly vis-light active Ni,La-codoped SrTiO 3 photocatalysts were successfully synthesized with sol–gel process. The characterization results show that the calcination temperature has a strong influence on the physical–chemical properties of as-synthesized photocatalysts. The surface area and porosity, even the initial adsorption rate for malachite green (MG), decreased with increasing calcination temperature. To evaluate the photocatalytic activities, the photodegradation of a water contaminant (MG) was carried out under visible light irradiation. The as-synthesized photocatalysts exhibited a high vis-light activity, and a 100% degradation of MG was observed for the Ni,La-SrTiO 3- x catalysts calcined at low temperature under visible light irradiation for 1 h, during which only 7% and 15% of MG was degraded for self-degrade and commercially available photocatalyst Degussa P25, respectively. The high vis-light activity is a result of the best combination of many properties, such as the intensive visible light response, the large surface area and pore volume and the high initial adsorption rate for substrate.