This study synthesized Mg-doped ZnO nanoparticles using the co-precipitation method with doping concentrations ranging from 2 % to 8 %. The structural, morphological, and optical properties of the synthesized nanoparticles were systematically characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and UV-Visible spectroscopy. XRD analysis confirmed the successful incorporation of Mg2+ ions into the ZnO lattice, evidenced by lattice parameter shifts and a significant reduction in crystallite size from 30.91 nm (pure ZnO) to 18.10 nm (6 % Mg doping). SEM images showed uniform morphology with reduced particle agglomeration at optimal doping levels, while FTIR analysis identified characteristic Zn-O and Mg-O bonding vibrations, confirming structural integrity. UV-Vis spectroscopy revealed strong absorbance in the UV region, with the band gap energy decreasing from 3.68 eV (pure ZnO) to 3.16 eV (6 % Mg doping), indicating enhanced optical properties conducive to improved photocatalytic performance. The photocatalytic activity of Mg-doped ZnO nanoparticles was evaluated by degrading Basic Fuchsin (BF) dye under UV light irradiation. The Mg-doped ZnO nanoparticles exhibited significantly enhanced photocatalytic performance compared to undoped ZnO, achieving a maximum degradation efficiency of 99.38 % at 6 % Mg doping within 100 min. Optimal photocatalytic conditions were observed at pH 6, using 0.1 g of catalyst and an initial dye concentration of 10 ppm. These enhancements were attributed to improved electron-hole pair separation and increased generation of reactive oxygen species (ROS), facilitated by the strategic incorporation of Mg. To complement the experimental findings, Density Functional Theory (DFT) simulations were performed, integrating the Conductor-like Screening Model for Realistic Solvation (COSMO-RS), Reduced Density Gradient (RDG), and Quantum Theory of Atoms in Molecules (QTAIM). The DFT analysis revealed enhanced charge separation, optimized electron transfer dynamics, and stronger adsorption interactions at Mg-doped sites, which promoted efficient ROS generation. The calculated valence band (VB) and conduction band (CB) edge potentials supported the formation of a Z-scheme heterojunction mechanism, enhancing charge separation and minimizing recombination. These theoretical insights aligned with the experimental observations, confirming that Mg doping effectively enhances photocatalytic efficiency by optimizing electronic interactions and promoting reactive surface dynamics. This integrated experimental and theoretical investigation demonstrates that Mgdoped ZnO nanoparticles exhibit superior photocatalytic properties, making them highly effective for environmental remediation applications, particularly in degrading organic pollutants in wastewater treatment. The study highlights the potential of Mg-doped ZnO as a promising photocatalyst for sustainable environmental solutions.

Chitosan, a naturally occurring biopolymer derived from chitin, has emerged as a highly promising instrument for the production and application of metal nanoparticles. The present review delves into the several functions of chitosan in the development and operation of metal nanoparticles, emphasizing its aptitudes as a green reducing agent, shape-directing agent, size-controlling agent, and stabilizer. Chitosan's special qualities make it easier to manufacture metal nanoparticles and nanocomposites with desired characteristics. Furthermore, there is a lot of promise for chitosan-based nanocomposites in a number of fields, such as metal removal, water purification, and photoacoustic, photothermal, antibacterial, and photodynamic therapies. This thorough analysis highlights the potential application of chitosan in the advancement of nanotechnology and the development of medicinal and environmental solutions.