Wurtzite phase Co-doped ZnO nanorods: Morphological, structural, optical, magnetic, and enhanced photocatalytic characteristics

Abstract

The design and development of one-dimensional nanostructures have been gaining considerable interest owing to the exceptional optoelectronic and catalytic properties of these structures. Thus, herein, wurtzite phase polycrystalline one-dimensional nanostructures of pristine and Co-substituted ZnO nanorods were fabricated using the hydrothermal method. Co ion substitution into the ZnO lattice was confirmed by structural analysis. Furthermore, an X-ray photoelectron spectroscopic survey suggested that Co ion inclusion in the host Zn2+ site occurred with a Co2+ oxidization state. The quenching of band gap with the Co inclusion into ZnO host sites was determined through optical studies. Room temperature hysteresis curves demonstrated the superparamagnetic nature of the synthesized ZnO and Co-doped ZnO nanorods. The photocatalytic activity of the synthesized nanorods was estimated by the exclusion of Rhodamine-B degradation under artificial solar light illumination. Distinctly, 66.5% photocatalytic degradation efficiency was achieved in Co-doped ZnO nanorods over 100 min; however, only 64.13% efficiency was observed for bare ZnO nanorods over 120 min. The enhanced photocatalytic activity in the Co-doped ZnO sample could be due to the creation of huge trapping sites, massive surface area, and generation and consequent separation of electron and hole pairs.