A comparative study on mesoporous and commercial TiO2 photocatalysts for photodegradation of organic pollutants

Abstract

The photocatalytic activity of the mesoporous TiO2 nanoparticles for the photooxidation of different pollutants molecules such as methylene blue dye (MB), methanol, imazapyr, and phenol were evaluated and compared to that of the commercial photocatalysts either Aeroxide TiO2 P-25 or Hombikat UV-100. The XRD and nitrogen isotherm results of mesoporous TiO2 confirmed that TiO2 nanocrystals with anatase phase were obtained and they possess large pore volume and high surface area of 0.29 cm3 g−1 and of 162 m2 g−1, respectively. The photocatalytic efficiency of mesoporous TiO2 is 100% for all employed pollutants molecules, however it reduced to 60–80% and 40–60% using Aeroxide TiO2 P-25 and Hombikat UV-100, respectively. The initial photodegradation rate of the pollutants molecules over mesoporous TiO2 is higher 2 and 3–6 times than that Aeroxide TiO2 P-25 and Hombikat UV-100, respectively. The enhancement of mesoporous TiO2 is explained by easy diffusion of pollutants molecules into TiO2 pores, minimize light scattering and excess •OH accumulated concentration into pores. The mesoporous TiO2 nanoparticles possesses the transport characteristics of pollutants molecules involved in the photocatalytic reaction and, thus, promote the comprehensive photocatalytic activity.