Bandgap Modification of ZnO Nanorods for Enhanced Photocatalytic Application

In this paper, we report the bandgap modification of ZnO-based nanorods (ZnO NRs) through carbon-based nanocomposite (ZnO/rGO) and metal doping using Cu, Ni, Bi, Co, and Mg ions as the dopants. The hydrothermal method was used to grow the nanorod's structure by incorporating a metal doping solution during the growing process and rGO coating. The analysis of the synthesized materials shows that metal doping affects the bandgap of the ZnO NRs. The band gaps of pristine ZnO NRs, ZnO NRs/rGO, Cu, Ni, Bi, Co, and Mg-doped ZnO NRs are 3.25, 3.17, 3.07, 3.15, 3.11, 3.18, and 3.14 eV, respectively. Cu-doped ZnO NRs have the most significant reduction in bandgap energy compared to other metal-doped ZnO NRs. Meanwhile, the rGO coating causes bandgap reduction of ZnO NRs from 3.25 to 3.17 eV.