Cu-loaded C₃N₄-MgO nanorods for promising antibacterial and dye degradation

Photocatalytic and magnetic stability of two-dimensional nanomaterials is enhanced by metal doping, which is an environmentally friendly technique used in various industries. There is an urgent need to discover new antimicrobial compounds or extracts to address the crucial problem of increasing microbial resistance against current antibiotics. Similarliy, the whole world is facing water crisis and a possible cost-effective solution is photocatalysis. In this study, an economical and convenient co-precipitation method was adopted to synthesize copper (Cu) loaded graphitic carbon nitride (g-C₃N₄) and magnesium oxide (MgO) composites. Various concentrations (2.5, 5, 7.5, and 10%) of Cu were doped into a fixed amount of g-C₃N₄/MgO nanostructures for efficient photocatalytic and antimicrobial activities. Results showed that 2.5% Cu loaded samples exhibited best possible results for the photocatalytic activity and 10% loaded Cu nanocomposites displayed enhanced antimicrobial performance. Improved crystallinity and increase in crystal size upon doping were confirmed with X-ray differaction (XRD) analysis, which was corroborated with Selected Area Electron Diffraction (SAED) results. Fourier-transform infrared spectroscopy (FTIR) revealed that MgO spectra consisted of stretching vibrations of Mg-O bond and other functional groups with minor changes in the vibrational modes upon doping. An high resolution transmission electron microscope (HRTEM) fitted with Gatan ® digital software indicated hexagonal phase formation in as-prepared samples and nanorods upon doping, with confirmed d-spacing values. The UV–visible spectroscopy (UV–Vis) analysis exhibited a slight redshift in absorption intensity leading to decreased bandgap (Eg) for Cu-loaded g-C₃N₄/MgO. Photoluminescence (PL) spectra were acquired to investigate the recombination of electron–hole pairs. X-ray photoelectron spectroscopy (XPS) was employed to evaluate the elemental and surface composition with binding energy alterations of Cu-loaded g-C₃N₄/MgO nanorods. The thermal stability and behavior of synthesized samples were investigated by differential scanning calorimetry thermoanalytical (DSC) analysis. Photocatalytic activity (PCA) of as-prepared samples were evaluated against methylene blue and ciprofloxacin (MB&CF) dye in acidic, neutral and basic medium. Furthermore, the efficient antimicrobial potential was evaluated against Escherichia Coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria.