Tailoring and optimization of hybrid ZnO:TiO2:CdO nanomaterials for advance oxidation process under visible light

The hybrid ZnO:TiO2:CdO (ZTC) nanomaterials were synthesized through a simple route sol-gel precipitation method for advance oxidation process (AOP). The morphology of ZnO:TiO2 to ZnO:TiO2:CdO has been changed from nanorods to nanoflakes and then to cauliflower by increasing the volume fraction of CdO in sample ZnO:TiO2.The particle sizes were found 34 nm and 51 nm for ZnO:TiO2 and [(0.4)ZnO:(0.6)TiO2]:CdO (1:1) samples, respectively and confirmed by HRTEM. The composite phase was observed in the XRD pattern and obtained different phases of hybrid ZnO:TiO2:CdO nanomaterials which is attributed to the synergistic effects in AOP. The optical bandgap were decreased from 3.24 eV to 2.16 eV by adding the CdO in [(0.4)ZnO:(0.6)TiO2]. The advance oxidation process was investigated via the degradation of methyle orange (MO) and methyle blue (MB) for all hybrid nanomaterials in visible light. The catalysts dose 7 gm/L of sample ZTC4 shows the highest degradation efficiency 98% and 96% in both organic dyes MO and MB with decreases rate of recombination and boosted photo induced charge carriers in the catalyst. The estimation of mineralization factors of dyes were examined through BOD and COD tests followed by AOP. © 2020 Elsevier B.V.