Synthesis and the effect of calcination temperature on the physical-chemical properties and photocatalytic activities of Ni,La codoped SrTiO3

A series of highly vis-light active Ni,La-codoped SrTiO3 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-SrTiO3-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. (C) 2010 Elsevier B.V. All rights reserved.