Synthesis and Characterization of Cadmium Doped Zinc Oxide Nanoparticles for Visible Light Driven Catalytic Removal of MB and RhB Dye: Experimental and Computational Analysis

The quest for fetching an excellent visible light driven photocatalyst is rapidly growing. In this research work, a simple, facile and cost-effective sol–gel method has been described to fabricate (1, 2, 3 and 4 At%) cadmium (Cd)-doped ZnO nanoparticles. Effect of various concentration of Cd on structural, optical and morphological properties of ZnO has been intensively investigated using characterization techniques such as SEM, XRD, EDX, PL, BET and UV–VIS. Photocatalytic activity of prepared nanomaterials has been evaluated for the degradation of methylene blue (MB) and rhodamine-B (RhB) dye in the presence of visible light. Quite interestingly, the best degradation efficiency of 91% for MB and 89% for RhB was exhibited by 3% Cd-doped ZnO sample which attributes to the lowering of bandgap energy due to incorporation of dopant element. Increasing the doping concentration beyond this level has detrimental effects in dye degradation owing to the Burstein-Moss effect. Additionally, optimization of various parameters such as pH, dye concentration and catalyst loading were thoroughly investigated. RF module of COMSOL Multiphysics 5.3a has been used to corelate the theoretical results with experimental findings.