Comparison of photocatalytic reaction of commercial P25 and synthetic TiO2-AgCl nanoparticles

Abstract

Titanium dioxide in powder form is largely used as a catalyst in the field of detoxification of aqueous effluents by photocatalysis. One of the most efficient commercial photocatalysts is TiO2/P25 manufactured by flame hydrolysis. In this work, we compared the photocatalytic efficiency between this commercial P25 and a synthetic TiO2-AgCl prepared in our laboratory by sol-gel method. The photocatalytic activities of P25 and TiO2-AgCl were tested using methylene blue (MB) solution under UV and visible light irradiation. The P25 and TiO2-AgCl photocatalyts were characterized by XRD, FT-IR, and SEM. Synthesized temperature had an effect on phase transformation of TiO2leading to a photoactivity. The results of the photodegradation experiments explain this difference between the P25 and TiO2-AgCl. For the TiO2-AgCl system, MB was significantly more degraded under UV exposure than when it was exposed to the visible light. The significant enhancement in the TiO2-AgCl photoactivity under UV irradiation can be ascribed to simultaneous effects of AgCl deposits both by acting as electron traps and enhancing the MB adsorption on the TiO2-AgCl surface. It is noted that TiO2-AgCl nanoparticles calcined at 400°C show high composition of anatase phase with the smallest crystallite size, factor responsible for the enhancement of photocatalytic activity. It was also apparent that photocatalytic activity of TiO2-AgCl nanoparticles is higher than a commercial P25 due to a higher concentration of OH radicals on TiO2 surface and a smaller crystallite size. Furthermore, the photocatalytic kinetic were also observed.