Synthesis and Characterization of Zinc Oxide Nanoparticles Co Doped with Sulfur and Copper for Photo catalytic Activities and Extending Shelf-Life of Orange Fruit

Abstract

Nowadays, environmental pollution is induced by the release of persistent dyes from industries. Orange fruits have a relatively short shelf-life of only 3-5 days at room temperature, and conventional packaging methods, such as paper or plastic, can only extend their shelf-life to 7-10 days. To overcome the limitations of previous approaches, it is necessary to explore new solutions that prevent secondary pollution and reduce the spoilage of fruits. Researchers have tried to use various advantages of metal oxide nanoparticles (MONPs) to overcome these problems. We have been attempting to overcome problems associated with the ZnO-NPs via the preparation of its NP materials with other metal oxide and doping with appropriate types of nonmetals. This study was to prepare ZnO NPs with low energy band gaps like Cu and dope them with S to further enhance their photocatalytic properties and extend the shelf-life of orange fruit. The synthesis of Cu & S-ZnO NPs has been carried out sol-gel method. The synthesized NPs were characterized by UV-Vis, XRD, SEM, and FT-IR. The energy band gap information from UV-Vis characterization shows that the successive decrement values, 3.07 eV, 2.94 eV, 2.80 eV, and 2.59 eV are for ZnO NPs, Cu-ZnO NPs, S-ZnO NPs, and Cu & S-ZnO NPs respectively. The XRD characterization shows that the synthesized samples were highly crystallized. The SEM image of ZnO NPs shows that the shape of the nanoparticle is rod-shaped whereas a spherical shape was observed for Cu-ZnO NPs, S-ZnO NPs, and Cu & S-ZnO NPs. The photocatalytic performance of the nanomaterials was evaluated by their ability to degrade methylene blue dye. The photocatalytic efficiency of 0.06 g/L of catalytic dose per 10 mg/L dye solution at pH=11 was 99 %, 96.7% 92.6%, and 89.7% for, Cu &S-ZnO NPs, S-ZnO NPs Cu-ZnO NPs, and ZnO NPs, respectively. Furthermore, the shelf-life of Orange fruits was significantly extended when treated with the Cu &S-ZnO NPs, demonstrating their potential for use in orange fruit preservation.