Abstract
The structural and phase analysis of Li@ZnO nanostructures (NSs) were tested by X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM exhibits the mixture of nanoflakes and nanoparticles at 1 wt% Li, and spherical shaped nanoparticles at 7 wt%, respectively. TEM images show the nanoflakes with thickness (12-37 nm) and diameter of nanoparticles (38-63 nm) at 1 wt%, and size of nanoparticles with 34-84 nm at 7 wt%, respectively. Raman spectra exhibit the two major modes at 107 and 446 cm(-1) were credited to longitudinal phonon modes. The optical bandgaps of 3.277-3.289 eV were evaluated from the optical spectra on basis of Kubelka-Munk function F(R) using Tauc's relation. Red shift in absorption coefficient with wavelength indicates the optical bandgap decreased with increasing Li contents above 3 wt%. The photocatalytic activity of pristine and Li@ZnO NSs were investigated in the photodegradation of organic dye methylene green (MG) solution under UV irradiation. The photocatalytic study showed significant activity improvement in the Li-doped ZnO. The sample with 7 wt% Li-doped ZnO exhibited 6.1 times higher activity compared to neat ZnO sample.