Preparation and structural characterization of binary catalyst for dye wastewater

Abstract

Synthetic dyes used in most industries have persistence chemical compounds which cannot be degraded by conventional method. To overcome this problem, researchers utilize photocatalytic oxidation and TiO2 has become favourite photocatalyst. However, TiO2 has wide band gap and needs modification. One of the modifications is binary catalyst which found to be more effective as it commonly binds another photocatalyst that is readily exist in visible region to TiO2. Over the past 5 years Ag2O has been a chosen catalyst due to its low band gap. However, Ag2O often experiences self-aggregation. Thus, the optimum doping ratio of TiO2/Ag2O was determine by physical blend of TiO2 and Ag2O into 2 ratios, which were 1% Ag2O and 5% Ag2O. TiO2 was synthesized using sol gel method and Ag2O was synthesized using co-percipitation method. Both catalysts were blended physically and characterized using FESEM-EDX and XRD analysis. EDX mapping analysis showed TiO2/ Ag2O -5% exhibit better distribution of Ag2O. In addition, XRD analysis shows TiO2/ Ag2O -5% has more intense Ag2O peaks compare to TiO2/ Ag2O -1%. Based on the characterization results, TiO2/ Ag2O-5% showed promising ratio loading for dye wastewater photocatalytic degradation.