Pt nanoparticles/TiO2 for photocatalytic degradation of phenols in wastewater.

Pt nanoparticles/TiO2 catalysts were prepared and evaluated for UV-photocatalytic degradation ofphenol and 2-chlorophenol (2-CP) in synthetic wastewater solutions. The catalysts were synthesized by immobilizing colloidal Pt nanoparticles onto titanium dioxide (rutile TiO2). Analytical techniques, such as standard Brunauer-Emmett-Teller isotherms, X-ray diffraction, transmission electron microscope, were utillized for investigating the specific surface area, structure, and particle size distribution of the catalysts and its components. The photocatalytic activities of both phenol and 2-CP solutions were studied in a 1L batch photoreactor independently, under 450 W UV irradiation. Samples were drawn at regular intervals and residual concentration of phenol and 2-CP in the samples was analysed using an UV-visible spectrophotometer. Parameters controlling the photocatalytic process, including catalyst concentration, solution pH, and initial phenol (2-CP) concentration, were investigated. The obtained results revealed that Pt/TiO2 showed higher photocatalytic degradation for both phenol and 2-CP pollutants in solution (as compared to the rutile TiO2). The degradation efficiencies of 87.7% and 100% were obtained for phenol and 2-CP, respectively, under optimized conditions (0.5 g/L catalyst with a pollutant concentration of 50 mg/L after irradiation time of 180 min).