Improved synthesis of cobalt‐doped TiO₂ catalyst using ultrasound and subsequent application for Acid Violet 7 degradation

Abstract The current investigation deals with improving the synthesis of cobalt‐doped titanium dioxide (TiO 2 ) utilizing both ultrasound‐assisted and conventional impregnation methods with an objective to obtain better catalyst characteristics. The impacts of process parameters such as sonication power, irradiation time, duty cycle and precursor doping on the catalyst characteristics have been analysed to optimize the catalyst characteristics including its particle size. Different characterization methods, including XRD, BET, TEM and FTIR have been used to compare the catalysts produced using both approaches under optimal conditions. Catalyst synthesized at 1 mol% doping, 90 min as irradiation time, 80 W as sonication power and 50% as duty cycle showed a minimum particle size of 231 nm and surface area of 9.2 m 2 /g. The catalyst obtained utilizing the ultrasound‐assisted technique was obtained in significantly lesser time (90 min) compared to the catalyst obtained using the conventional approach (24 h). Photocatalytic oxidation tests carried out to determine the activity also showed that the Co‐doped TiO 2 catalyst obtained ultrasonically showed maximum activity for degradation of Acid Violet 7 in conjunction with H 2 O 2 at the optimal loading.