Influence of ZnO Ions on Micro-structural and Luminescence Properties of Host-lattice (CuO−ZrO₂) Nano Hybrid

Hydrothermal synthesis of un-doped and Zn-doped CuO−ZrO 2 nanohybrid powders was carried out at ambient temperature. Comprehensive characterization techniques such as XRD, SEM-EDAX, UV–vis DRS, FT-IR, and PL spectroscopy were employed to investigate structural, morphological, and optical properties. XRD analysis confirmed the presence of tetragonal and monoclinic ZrO 2 phases without ZnO-related secondary peaks. Zn doping led to peak shifts and intensity variations, indicating the stabilization of the tetragonal phase. Crystallite sizes were estimated to be around 26 nm using Debye–Scherrer and W-H methods, with a slight decrease upon Zn doping. UV–vis DRS revealed energy band gaps of 3.08 eV for the un-doped sample and 3.20 eV for the 0.3% ZnO-doped sample, showing a decrease in band gap with increasing ZnO content. SEM images displayed uniform flake-like layers interconnected by narrow wires, with Zn doping enhancing the bonding length between wires. PL spectra exhibited broad visible emission for un-doped samples, while Zn doping resulted in two peaks in the UV-visible region. CIE colour coordinates and correlated colour temperature (CCT) values indicated the samples’ potential for warm light applications. The results suggest that ZnO doping enhances both structural and optical properties of CuO−ZrO 2 nanohybrids. The ZnO doped CuO−ZrO 2 has shown excellent selectivity and response towards Benzene gas at room temperature.