Using ZnO, NiO, and ZnO/NiO as Nano Photocatalyst for Removal of Acid Violet and Rhodamine B from Wastewater

Photocatalyst process as a green method can help significantly remove water pollutants. In his regard, various nanostructures can be applied as a photocatalyst for photodegradation of different dyes. In his work, zinc oxide nanoparticles (ZnO NPs), nickel oxide nanoparticles (NiO NPs), and zinc oxide/nickel oxide nanocomposites (ZnO/NiO nanocomposites) were synthesized through facile and simple co-precipitation route. The polyvinylpyrrolidone (PVP) was applied as a capping agent for controlling of particle size. The crystallinity and morphological properties of prepared products were studied via X-ray diffraction pattern (XRD) and scanning electron microscope (SEM) analysis. The optical band gaps of prepared ZnO NPs, NiO NPs, ZnO/NiO nanocomposites were calculated 3.16 eV, 3.43 eV, and 2.94 eV via UV-Vis-assisted plotting of the (αhν)² versus photon energy (hν). The obtained products applied as photocatalyst material for phodegradation of acid violet and rhodamine B (RhB). Also, catalyst dosage (0.03, 0.06, and 0.09 g) as an important parameter choose to investigate in the designed photocatalytic process. It is found that prepared ZnO NPs, NiO NPs, and ZnO/NiO nanocomposites shows excellent photocatalytic activity, although ZnO/NiO nanocomposites provided better removal (93.8%) compared to ZnO NPs (86.1%) and NiO NPs (81.5%) toward acid violet. The same trend was observed for rhodamine B. The results confirm that 0.06 g is the optimum dosage of catalyst.