Impact of Mg doping on optical, dielectric and antibacterial properties with invitro analysis of CuAlO2 spherical-flower nanostructures: modeling and experimental results

Nanoparticles (NPs) of Mg doped CuAlO₂ of the composition CuAl_1−xMg_xO₂ (x = 0.0, 0.05) have been successfully synthesized through auto combustion method. XRD and FESEM techniques were applied for the characterization of their microstructures. Such characterization confirmed the successful doping of CuAlO₂ NPs with Mg without any appearance of parasitic peaks, thus maintaining their single phase as well. The application of the Hall-Williamson relation to XRD results facilitated the extraction of sample particle size, which was found to increase after the introduction of the Mg dopant. With the introduction of Mg dopant, a decrement in the optical band gap was observed through a red shift in the absorbance spectrum. Doping also generated enhancement of the dielectric permittivity as well as conductivity, as observed through the temperature-dependent LCR spectroscopy. An application of Mg doped-CuAlO₂ was proved as an anti-bacterial agent disk diffusion assay method against Escherichia coli (E. coli.) as Gram Negative and Streptococcus bovis (S. bovis) as Gram Positive bacteria, respectively. This study investigates the “Impact of Mg doping on optical, dielectric and antibacterial properties for CuAlO₂ spherical-flower nanostructures”. The synthesized pure and Mg-doped CuAlO₂ nanoparticles present a substantial prospect for both theoretical research and the development of CuAlO₂-derived biomedical applications. The dielectric characteristics, such as permittivity, loss tangent, and AC conductivity, were found to increase with Mg doping. Additionally, Mg-doped CuAlO₂ nanoparticles exhibited more potent antibacterial activity than pure CuAlO₂. The incorporation of Mg induced a red shift in the absorption peak, signifying a decrease in the band gap energy from 3.02 eV to 2.98 eV. The modulation in the energy band structure due to Mg doping in CuAlO₂ crystal have also been calculated and analyzed in the work using the DFT based First Principle calculations. For DFT analysis the authors have utilized HSE06 hybrid functional paired with double-ζ polarized basis set for accurate energetic calculations. The modulation in the energy band structure due to Mg doping in CuAlO₂ crystal has also been calculated and analyzed in the work using the First Principle calculations.