Swift heavy ion induced effects on structural, optical and photo-catalytic properties of Ag irradiated vertically aligned ZnO nanorod arrays

Development of 1D array platforms for environmental remediation is of vitality in the current scenario where water bodies are overborne by organic pollutants. ZnO nanorod arrays (ZNRA) were synthesized using solution growth method and were irradiated by 120 MeV Ag ions at various ion fluences of 1E11, 5E11, 1E12 and 5E12 ions/cm(2). The structural, morphological and optical properties were studied using X-ray diffraction (XRD), Field Emission Scanning Microscopy (FESEM), UV and Photoluminescence spectroscopy respectively. While the FESEM analysis shows that the length of ZNR is in the range of similar to 4 mu m and with a diameter ranging from 100 rim to 350 nm, the XRD results confirmed the formation of wurtzite hexagonal structure (0 0 2) of ZnO. The XRD peak broadened with the increase of Ag ion fluences from 1E11 to 5E12 ions/cm(2). The UV absorption spectra show a red shift of the band edge absorption with increase in ion fluences and bandgap decreases from 3.24 eV to 2.94 eV. The photocatalytic activities of Ag irradiated ZNRA were evaluated through the degradation of methylene blue under the visible region of light irradiation. The degradation efficiencies for pristine and 5E12 ions/cm(2) Ag irradiated ZNRA were 54.24% and 87.98% respectively for methylene blue after 120 min. These photocatalytic results show that the degradation efficiency increases with the Ag ion irradiations. The possible mechanism behind this enhancement due to the Ag ion irradiation is also discussed.