Statistical Optimization for Photocatalytic Degradation of Methylene Blue by Ag-TiO2 Nanoparticles

The objective of the research work was to optimize the operational parameters like, catalytic dosage, pH and concentration of dye, for degrading methylene blue (MB) by silver (Ag) deposited titanium dioxide (Ag-TiO2) nanoparticles by photocatalysis using Taguchi L9 orthogonal array technique. The Ag-TiO2 were prepared by photodeposition technique and characterised for particle size, shape and crystallinity using particle size analyser, SEM and XRD respectively. Morphological results shows both TiO2 and Ag-TiO2 are spherical in shape, size of 63 nm and 92 nm respectively and are in anatase phase with traces of rutile phase. Taguchi results show that the optimum parameters are 0.3947 g/l of Ag- TiO2 catalyst, pH of dye 11 and irradiation time as 80 min for maximum catalytic degradation. From ANOVA results, irradiation time was found to be the most influencing factor (72.12%) followed by pH (19.73%) and catalyst amount (6.65%). Ag-TiO2 catalysis has superior degradation in contrast to undeposited TiO2 by 33.12%.