The Study of the Photocatalytic Degradation of Methyl Orange in the Presence of Zinc Oxide (ZnO) Suspension

Abstract

Photodegradation of methyl orange spectrum in aqueous ZnO suspension by UV irradiation has shown time-dependent UV photodegradation. Methyl orange shows absorption peaks at 463 nm in the visible region. The rate of decolourization was recorded with respect to the change in the intensity of absorption peaks at 463 nm. The absorbance decreased with time and finally disappeared as the irradiation was scattered with time. It is seen that about 40% of dye was degraded after 30 minutes whereas about 60% of dye degraded after hours. The effect of photo-catalyst concentration on the photo-degradation rate of the methyl orange dye was investigated by employing different concentrations of ZnO from 0.2 to 2.0 g/100 mL with dye concentration 2 mg/100 mL at normal pH of methyl orange solution. The highest decrease in the concentration of methyl orange solution was observed for the ZnO of 1.4 g/mL during 60 minutes of irradiation. After optimizing the catalyst concentration of ZnO suspension (1.4g/100mL), the photocatalytic degradation methyl orange solution was carried out by varying the initial concentration of dye from 6mg/100mL to 10mg/100mL in order to assess the appropriate concentration of the dye required for maximum degradation. The percentage of degradation of methyl orange is scattered with an increase in dye concentration. In the case of 7mg/100mL of MO solution about 68% of degradation was found after 60 minutes. The highest degradation of methyl orange is 64.458 which were obtained at pH 7.