Photocatalytic degradation of heavy metal in dairy milk by N-doped ZnO thin film using spray coating technique

Abstract

Zinc Oxide (ZnO) is a photocatalytic material. N-doped ZnO thin film can reduce heavy metals in milk. In the process, N-doped ZnO thin film photocatalyst is deposited on the glass by spray coating technique. N-doped ZnO thin film was characterized using UV-Vis (Ultraviolet/Visible Spectroscopy), X-Ray Diffraction (XRD) and FTIR (Fourier Transform Infrared). This study aims to investigate the reduction of heavy metals in milk due to N-doped ZnO thin film. In this study, dairy milk was obtained from farms in Central Java. Characterization results show that the band gap of N-doped ZnO thin film is 3.2 eV that N- doped ZnO thin film can function under visible light. Photocatalytic activity of prepared N-doped ZnO thin film was evaluated by the degradation of heavy metals in dairy milk. Duration of N-doped ZnO thin film degradation was found to vary from 0, 60, and 120 to 180 minutes. Heavy metal content in dairy milk is 0.5775 ppm. Addition of N-doped ZnO thin film to dairy milk reduced heavy metal content to 0.0053 ppm. In can then be inferred that heavy metal degradation using N-doped ZnO thin film is by as much as 89-99 %.