Preparation of Cobalt tungstate nanomaterials and study on sonocatalytic degradation of Safranin t

Abstract

Cobalt tungstate (CoWO4) nanoparticles were prepared by method of hydrothermal synthesis and regulated via adding different doses of surfactant sodium dodecyl sulfate (SDS). Then, degradation of dye Safranin T (ST) under the ultrasound irradiation utilizing CoWO4 nanoparticles as sonocatalysts was investigated. Through a series of experiments such as ultrasonic degradation methods, the following results were got: Firstly, CoWO4 nanoparticles with different dosage of SDS had good sonocatalytic performance in decomposition of ST. And the degradation rate of ST reached the optimum value of 85.9% under the conditions of CoWO4 with dosage of 0.5 g SDS (CoWO4-0.5), 1.0 g/L CoWO4-0.5, 15 mg/L initial dye concentration and 160 W ultrasonic power in 120 min, followed by the TOC removal rate of 74.57%. Secondly, there was a significant synergistic effect between COWO4-0.5 and ultrasonic (synergy index value was 3.75 for US + COWO4-0.5). Thirdly, the degradation of ST is mainly attributed to the generating of hydroxyl radicals and other reactive oxygen species. And the catalyst decomposes nitrogen atom in the ST molecule to produce NO3– ion. Lastly, CoWO4-0.5 exhibited good stability and reusability in the process of sonocatalytic decomposition after four cycles. With these results, a new research reference might be provided for degradation of organic pollutants.