Synthesis and characterization of ZnO nanorods via hydrothermal route for wastewater recycling

In this work, highly efficient ZnO nanorods (NRs) were prepared using an easy and costeffective hydrothermal process. The Synthesized ZnO NR have been analyzed for their structure, morphology, and optical characteristics using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier Transform Infrared (FTIR), and ultraviolet-visible (UV-visible) spectroscopy, respectively. Additionally, a test is conducted on the ZnO nanorod's photocatalytic efficiency towards the degradation of certain dyes, Methylene Blue (MB) and Methyl Orange (MO). The FESEM investigation revealed that the ZnO nanostructures show nanorods with varying diameters (needle-like shape) with an estimated size of (10 to 20) µm. According to the XRD examination, the NRs had a hexagonal-shaped wurtzite pattern, exhibiting an average crystallite diameter of about 50 nm. FTIR spectra confirmed that functional groups from the substance being extracted were present in the ZnO NRs. The band-gap value of 3.37 eV was determined through the TAUC plot model from the ultraviolet-visible spectrum data. In the presence of as-synthesized ZnO NRs, the MO dye degraded by 100 percent in 46 minutes, but the MB dye significantly degraded by approximately 100 % in 20 minutes with high degradation rate constants kMO = 0.086 min-1 and kMB = 0.180 min-1, respectively.