Sono-coprecipitation synthesis and physicochemical characterization of CdO-ZnO nanophotocatalyst for removal of acid orange 7 from wastewater

In this research, CdO-ZnO nano-photocatalysts were synthesized in various compositions by ultrasound assisted co-precipitation method. The samples were investigated via analyses of XRD, FESEM, BET, DRS, FTIR and EDX dot mapping to determine the physical, chemical and optical properties of the nanocomposites. Successful synthesis of CdO-ZnO photocatalyst in crystalline form was confirmed by XRD analysis resulting lower crystallite sizes for ZnO compared to CdO in the composites. The FESEM analysis demonstrated a nanostructured catalyst with a distinct decrease in particle size by addition of CdO to ZnO photocatalyst. The particle size distribution analysis determined an average particle size of 67.9 for the CdO25ZnO75-SCP sample. According to EDX dot mapping results, the Cd dispersion has been enhanced for the case of sonicated samples. Consequently, these cases have represented higher BET surface area results. Degradation of azo dye from synthetic wastewater was performed in order to evaluate the photocatalytic activity of the samples. The characterization analyses along with the performance tests concluded better properties in the case of ultrasound assisted co-precipitation. The investigation of various compositions resulted the best performance for CdO50ZnO50-SCP nanophotocatalyst reporting 69% of contaminant degradation during 140 min of the experiment.