Decolarization of methylene blue and methyl orange with Ag doped TiO2 under UV-A and UV-Visible conditions: process optimization by response surface method and toxicity evaluation

Abstract

MB decolarization with pure TiO2 and Ag doped TiO2 based photocatalytic system were investigated under UV-A and UV-Visible conditions. Different ratios of Ag were used as metal dopant. 1% Ag-TiO2 increased the decolorization efficiencies of MB and MO dyes, also the kapp constant enhanced under UV-A and UVVisible conditions. A central composite analysis showed the effect of initial dye concentration, pH, Ag-TiO2 concentration and the reaction time of photocatalytic process under UV-A irridation in both dyes. The photocatalytic degradation pathways of both dyes by Ag doped TiO2 catalyst were obtained in this study. According to these results, the application of Ag-TiO2 catalyst are proved to be more effective than pure TiO2 catalyst for both MB and MO removal. The toxicity test of Daphnia Magna shows that non toxic wastewater discharge to the receiving environment could be possible with photocatalytic degration by Ag-TiO2 catalyst.

Synthesis and characterization of magnesium doped titania for photocatalytic degradation of methyl red

“…AVASARALA et al in the same way found fine crystals aggregated to form irregular shaped particles of magnesium doped titania catalyst with average size of 1.04 µm range [31]. CIFCI observed silver doped titania particles having different shapes of grains with irregular boundaries and many smaller crystals combined to form aggregates [66]. Similarly, Aware and co-workers obtained spherical shaped zinc doped titania nanoparticles with a slight agglomeration [67].…”

“…Similarly, SHIVARAJU and co-workers compared Mg-doped titania polyscales with pure titania and found it to be more efficient photocatalyst for the degradation of industrial dyes like methyl violet, methyl red, methyl orange, brilliant green and brilliant blue with 100%, 80%, 79%, 73% and 64% dye degradation respectively [35]. In a study Cifci observed that maximum degradation for methylene blue and methyl orange was achieved with titania nanoparticles doped with 1% silver ions that decreased with further increase in dopant concentration [66].…”