Effect of calcination on microstructure and photocatalytic activity of hierarchical titanium dioxide derived from titanate micro-spherulites

Photocatalyst, in particular titanium dioxide (TiO2), is a promising solution which degrades organic pollutant in water into non-harmful substances. Titanate microstructures have shown exceptional high surface area, important in the photocatalytic degradation process. The purpose of this study is to investigate the change in morphology and microstructure after various calcination parameters and their effects on the photocatalytic degradation of methyl orange under UV-visible light irradiation. Titanate micro-spherulite (TMS) was synthesized through electrochemical spark discharge spallation. The titanate was calcined at different maximum temperature (300°C, 400°C, 500°C, 600°C, 700°C) with constant heating rate, and different heating rate (0.5°C/min, 5°C/min, 10°C/min, 20°C/min) with constant maximum temperature. Titanate transformed into the anatase phase after calcination. As calcination temperature increases, the micro-spherulite surface turns from nanosheet into nanoparticles, in line with the increase in crystallite size and decrease in specific surface area. TMS calcined at 500°C and 0.5°C/min showed comparable photocatalytic activity to commercial anatase.Bachelor of Engineering (Materials Engineering