Photocatalytic reaction and degradation of methylene blue on TiO2 nano-sized particles

Photocatalyst has been of considerable interest due to its new technology for environmental pollution. Among the photocatalyst semiconductors, titanium dioxide is known as a photocatalyst for the removal of environmental contaminants. In this research, we first designed a new self-made laboratory photocatalytic reactor and then photocatalytic properties of TiO2 nanoparticles are studied by using UV-A light and photodegradation of methylene blue as a water pollutant evaluated until the photocatalytic process optimizes with the process parameters. The parameters that were examined include: initial dye concentration, the mass of TiO2 nanoparticle, pH value, and TiO2 nano-sized particles. Absorbance spectra were measured using a spectrophotometer and the concentration of the test solution was calculated by using the Beer-Lambert Law. Our test results showed that the photocatalytic UV-A/TiO2 nanoparticle is a promising method for treating wastewater. The most important part is that with reduction of TiO2 particles from nano to micro scale, photodegradation time becomes very slowly and even did not reach to zero after 5 h. Also, photocatayst reaction efficency for 10 nm TiO2 nanoparticles improves to 90% within one hour and photodegradation completed after two hour, it means that the photocatalyst activity increases with increasing surface area.