The effect of sintering temperature on mesoporous structure of WO3 doped TiO2 powders

Abstract

In this study, WO3 doped TiO2 powders were synthesized via sol-gel method combined with a hydrothermal process. The effect of sintering temperature on mesoporous structure and catalytic activities of these powders were investigated. The physical analysis via X-ray diffraction indicates that prepared samples are a mixture of anatase and rutile TiO2 phases. X-ray peak analysis is used to evaluate the crystallite size and lattice strain by the Williamson-Hall analysis. Considering all the reflections of the anatase phase the lattice strain ranging from c = 9.505 to c = 9.548 is calculated, suggesting that microstrain decreases when calcination temperature increases. N2 adsorption-desorption analysis shows that the surface area and pore volume decrease with increasing temperature and that WOx-TiO2 powders primarily consist of mesopores. Sintering temperature induced a change in textural properties causing a systematic shift towards larger mesopores. Simultaneously, photoactivity in decolorization of methyl orange increases with increasing calcination temperature up to 700°C, followed by significant decrease with its further increase. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172022, Grant no. 172026, Grant no. 172015, Grant no. 172018, Grant no. 172001 and Grant no. III 45001]

Keywords

• WOx-TiO2 powders
• sintering
• mesoporous structure
• photocatalytic degradation
• Azo dye