Phase-dependant photochemistry of TiO2 nanoparticles in the degradation of organic dye methylene blue under solar light irradiation

This paper describes the photochemistry of nanoparticles of TiO2 in anatase, anatase/rutile, and rutile phases for the degradation of methylene blue (MB) under solar light irradiation. For this process, TiO2 nanoparticles were synthesized by a sol-gel method, and different phases were achieved by annealing the prepared particles at various temperatures. Further, the annealed products were subjected to structural, optical, and morphological characterizations. The photocatalytic measurements show that TiO2 in the anatase phase possesses superior activity towards the degradation of MB due to its smaller crystallite size, enhanced BET surface area, higher pore size, and low charge transfer resistance.