Sol–Gel Synthesis and Antibacterial Effects of a Nano-Enhanced Cd Doped ZnO Nanorod Conjugate

Abstract

In this work, ZnO and Cd doped ZnO nanorods (NRs) were synthesized using a hydrazine-assisted sol–gel method, followed by two annealing at temperatures (300 and 500°C). X-ray diffraction (XRD) analysis confirmed that the samples possess a hexagonal wurtzite crystalline structure. Transmission electron microscopy (TEM) revealed that the Cd doped ZnO nanoparticles are rod-shaped. X-ray photoelectron spectroscopy (XPS) indicated that Cd²⁺ ions successfully substituted into the Zn lattice. Photoluminescence (PL) analysis showed intense UV-region luminescence at 500°C due to Zn and oxygen vacancies and defects. These results suggest that Cd doped ZnO NRs annealed at 500°C could be promising candidates for next generation UV detectors. Furthermore, the antibacterial tests demonstrated that Cd²⁺ incorporation significantly enhanced that antibacterial effects of ZnO NRs, particularly against S. aureus (15 ± 0.85 mm) and E. coil (14 ± 0.71 mm) under light exposure. Thus, Cd-doped ZnO NRs offer great potential as an alternative antibacterial materials, especially in biomedical applications.