Heterogeneous sonocatalytic degradation of anazolene sodium by synthesized dysprosium doped CdSe nanostructures

•Hydrothermally synthesis of undoped and Dy-doped CdSe nanoparticles.•Investigating the performance of Dy-doped CdSe in sonocatalytic process for the decolorization of anazolene sodium.•High degradation efficiency of sonocatalytic process (91.32%) in comparison with sonolysis.•Development of a novel empirical kinetic model by nonlinear regression analysis.

Undoped and Dy-doped CdSe nanoparticles are synthesized and then characterized by the SEM, XRD, FT-IR, XPS and BET methods, which verify successful preparation of the doped catalyst. The sonocatalytic degradation of anazolene sodium as a model azo dye is higher than sonolysis process and the 2% Dy-doped CdSe with band gap of 1.42 eV exhibits the greatest sonocatalytic performance. The decolorization efficiency (DE%) of sonocatalysis with 2% Dy-doped CdSe, undoped CdSe and sonolysis after 90 min of the process is 91.32%, 56.13% and 39.14%, respectively. In addition, the sonocatalytic degradation of anazolene sodium increases with enhancement of the dopant, catalyst dosage, ultrasonic power, dissolved gasses and decreasing of initial anazolene sodium concentration. Furthermore, with addition of chloroform, sulfate, chloride and ethanol as the radical scavengers, the DE% decreases indicating the controlling mechanism of free radicals for the dye degradation. Besides, the results reveal the appropriate reusability of the catalyst and various degradation by-products are identified using the GC-MS technique. Eventually, the empirical kinetic model is expanded by nonlinear regression analysis for prediction of pseudo first-order constants in various operational conditions.

Graphical abstractSynthesis of Dy-doped CdSe by hydrothermal method and its application in the sonocatalytic process.Download high-res image (65KB)Download full-size image