CaCO₃@SiO₂ core–shell nanocomposites: advanced synthesis and multifunctional applications in CO₂ methanation, photocatalytic degradation, and molecular docking

This study presents the synthesis, characterization, and multifunctional applications of Calcium carbonate–silica (CaCO₃@SiO₂) core–shell nanocomposite (NCs) aimed at addressing environmental challenges. The NCs were synthesized using a co-precipitation and sol-gel method, resulting in core-shell structures that were thoroughly characterized through various techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and UV-Visible spectroscopy. The catalytic performance of the nanocomposites was evaluated for CO₂ methanation, achieving an impressive conversion rate of 87.84% at 360°C, demonstrating their potential for sustainable carbon utilization. Additionally, the photocatalytic activity was assessed through the degradation of Evans Blue dye and Fenitrothion pesticide under solar irradiation, with removal efficiencies of 99.4% and 99.92%, respectively, within 140 minutes. In-silico molecular docking studies indicated strong binding affinities with key bacterial and viral protein targets, suggesting potential antibacterial and antiviral applications. The results highlight the multifunctional capabilities of CaCO₃@SiO₂ NCs as promising materials for carbon capture, water purification, and biomedical applications, paving the way for innovative solutions in environmental and energy sectors. Graphical Abstract