Effect of heating rate on structure, morphology and photocatalytic properties of TiO2 particles: thermal kinetic and thermodynamic studies

In this study, TiO 2 powders were produced via sol–gel route at 500 °C for 2 h with distinct heating rates. TGA-DTA, XRD, SEM, Raman spectroscopy, XPS, UV–vis spectroscopy and photoluminescence characterization techniques were carried out for TiO 2 powders. Photocatalytic efficiency of TiO 2 powders on degradation of methylene blue (MB) solution was examined in terms of different heating rates. Thermodynamic and non-isothermal kinetic study of TiO 2 powders were estimated. TiO 2 powders showed anatase phase based on XRD results. Surface morphology of TiO 2 powders did not change with different heating rates. It can be concluded that heating rate played important role on band gap and photocatalytic activity. The band gap of the TiO 2 particles decreased from 3.25 to 2.95 with increasing heating rate. The photocatalytic activity results exhibit that T1 powders have the highest photocatalytic performances. The kinetic constant and photocatalytic degradation rate were 0.00678 min −1 and 83.48%, respectively. This could be attributed to high crystalline structure and low bulk vacancies or defects. Furthermore, TiO 2 powders showed good stability. This study exhibited a new way to enhance the photocatalytic performances of pure TiO 2 powders. Highlights TiO 2 powders were fabricated by sol–gel process at various heating rate regime. Effect of the heating rate on structure, morphology and photocatalytic properties was investigated. Non-isothermal and thermodynamic parameters of TiO 2 powders were studied. T1 sample exhibited the excellent photocatalytic efficiency.