Study on Effect of the Solvothermal Temperature on Synthesis of 3D Hierarchical TiO2 Nanoflower and Its Application as Photocatalyst in Degradation of Organic Pollutants in Wastewater

3D TiO2 hierarchical nanoflower was synthesized by template-free solvothermal alcoholysis of TiCl3 with the variation of reaction temperatures (130-200 degrees C). XRD, SEM, BET surface analysis, UV-VIS DR spectroscopy, FTIR analysis were performed to characterize the prepared TiO2 samples. Photocatalytic degradation of model organic pollutant such as methylene blue (MB) dye was investigated using all prepared samples under UV light illumination. Results show that reaction temperature directly affects the anatase phase content of TiO2 samples, crystal structures, crystalline size, particle size, surface area, pore structure, UV absorption capacity, and band gap of the synthesized samples. The sample prepared at reaction temperature 150 degrees C seems to be most efficient photocatalyst for degradation of MB with rate constant 0.0287 min(-1) [similar to 20.5 times higher than the sample prepared at 130 degrees C (0.0014 min(-1)) and 6.83 times higher than the sample prepared at 200 degrees C, (0.0042 min(-1))]. Optimization of reaction temperature at 150 degrees C was performed by testing different properties of the synthesized TiO2 nanoflower such as its surface area, organized morphology, bimodal pore-size distribution, and porosity which were synthesized at different solvothermal temperatures (130-200 degrees C).