The Effect of Structure and Form of TiO۲ Photocatalyst on the Methylene Blue Degradation from the Wastewater

Semiconductor photocatalyst reduction has been a new considerable technology for theremoval of various toxic pollutants such as dissolved heavy metals and organic materials. Titaniumdioxide with different forms is well-known as an excellent photocatalyst among the photocatalystsemiconductors for the wastewater treatment. In this work, firstly, TiO۲ was prepared in anatase and rutileforms by sol-gel methods. Then, the photocatalytic properties of anastase nanoparticles was evaluatedusing XRD, FT-IR, FESEM-EDX, and BET methods. The most important variables including methyleneblue dye concentration, TiO۲ nanoparticle dosage and pH under UVA light irradiation in ۹۰ min wereexamined to obtain the optimum conditions for the photocatalytic process. Also, the photocatalyticefficiency of anatase, rutile, and commercial TiO۲ was compared together for photodegradation ofmethylene blue. The absorbance peaks of FT-IR determined Ti-O-Ti bond and located in the type IVrelated to mesopor structure corresponding to IUPAC classification. The result of FESEM indicated thealmost spherical shape and existence of Ti and O in the particles which are pure. The maximumphotocatalytic efficiency of the as-prepared nanoparticle in methylene blue removal was about ۷۰% underthe optimized parameters including photocatalyst dose of ۰.۳ g/L, pH ≈۱۱, temperature ≈۳۰ °C and dyeconcentration of ۱۰ mg/L after ۹۰ minutes UVA irradation. The compression among anatase, rutile, andcommercial TiO۲ showed removal amount of anatase is more than rutile for reducing the mesoporousstructure in high activation temperature. Therefore, the experimental data showed that the as- synthesizedphotocatalst is able for industrial wastewater treatment.

کلیدواژه ها:

photodegradation ، anatas ، rutile ، mesopour