Enhanced efficiency of zinc oxide hydroxyapatite nanocomposite in photodegradation of methylene blue, ciprofloxacin, and in wastewater treatment
K. Manikandan, Naresh Kumar, R. Velmurugan, M. Gokulnath, S. Parvathy, Manikandan Ayyar, M. Swaminathan, P. Prabhu, Abdullah M. S. Alhuthali, Magda H. Abdellattif, Rajesh Haldhar, M. Khalid Hossain
Abstract
In this study, we report the improved photocatalytic performance of Hydroxyapatite-incorporated Zinc Oxide Nanocomposite (ZnO@HAp), synthesized using a simple precipitation method. The catalyst was characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopic analysis (FT-IR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-DRS), Scanning Electron Microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The formation of ZnO@HAp was confirmed by XRD, FT-IR, EDAX, and XPS. SEM images of the ZnO@HAp reveal that the particles were agglomerated, and spherical-shaped ZnO particles were present on the surface of HAp.The presence of particles in various forms, such as spherical and hexagonal structures, is visible on the surface of pure HAp in the TEM images of the material. The XPS analysis confirmed the presence and chemical states of essential elements (Zn, O, Ca, and P) in the ZnO@HAp composite. The photocatalytic efficiency of the synthesized composite was evaluated by the degradation of organic pollutants, including methylene blue and ciprofloxacin, as well as in domestic sludge water treatment. The removal efficiencies of 96.6% for methylene blue (30 min), 62% for ciprofloxacin (150 min), and 88% COD reduction in domestic sludge were observed. This composite gives remarkable degradation performance due to its stability and good photocatalytic properties. The results obtained from the prepared ZnO@HAp composite, compared to ZnO and pure HAp, showed higher photocatalytic efficiency with long-term stability, without any changes in the ZnO@HAp characteristics after five consecutive runs. The enhanced properties of the ZnO@HAp composite make it a promising candidate for environmental remediation applications, offering an effective solution for pollutant degradation in wastewater treatment.