Towards effective dye degradation and antimicrobial behavior of chitosan and C₃N₄-doped CdS nanoparticles

In this study, co-precipitation has been employed to develop carbon nitride (C₃N₄) and chitosan (CS)-doped CdS nanoparticles (NPs) to investigate the doping effect of CS and C₃N₄ on CdS to degrade MB dye and assess their antibacterial activity. Comparatively, the maximum dye degradation achieved by the previously reported binary blend of CdS-C₃N₄ was 85%, whereas the maximum degradation achieved by the currently prepared ternary nano-catalyst was 99.75%. Furthermore, CdS NPs were doped with a fixed amount of CS at various concentrations (2 and 4 wt%) of C₃N₄. Numerous techniques have been utilized to characterize doped NPs. The hexagonal phase of CdS was confirmed by XRD results, and doping caused a decrease in crystallite size, as calculated by the Debye Scherrer formula. Functional group existence was determined by FTIR; CdS was confirmed at 662 and 758 cm⁻¹, and doped CdS exhibited bond stretching and absorption at 1061, 1388, 1627, and 3434 cm⁻¹. The UV-Vis absorption spectra with blueshift after doping resulted in increased bandgap energy, which could be attributed to a reduction in crystallite size. PL spectra were utilized to observe the charge carrier transfer and trap sites of doped NPs. The presence of CdS formation and doping was observed using EDS. The morphology of the product was examined using HRTEM, which revealed spherical NPs agglomeration. C₃N₄-doped NPs demonstrated significant methylene blue (MB) dye degradation, while doped CdS samples exhibited considerable antimicrobial activity against Staphylococcus aureus and Escherichia coli bacteria.