Efficient Photocatalytic Dye Degradation and Bacterial Inactivation by Graphitic Carbon Nitride and Starch-Doped Magnesium Hydroxide Nanostructures

Abstract

The removal of hazardous pollutants from water is becoming an increasingly interesting topic of research considering their impact on the environment and the ecosystem. This work was carried out to synthesize graphitic carbon nitride (g-C3N4) and starch-doped magnesium hydroxide (g-C3N4/St-Mg(OH)2) nanostructures via a facile co-precipitation process. The focus of this study is to treat polluted water and bactericidal behavior with a ternary system (doping-dependent Mg(OH)2). Different concentrations (2 and 4 wt %) of g-C3N4were doped in a fixed amount of starch and Mg(OH)2to degrade methylene blue dye from an aqueous solution with bactericidal potential against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) pathogens. The textural structures, morphological evolutions, and optical characteristics of the as-prepared samples were analyzed using advanced characterization techniques. X-ray diffraction confirmed the hexagonal phase of Mg(OH)2with improved crystallinity upon doping. Fourier transform infrared spectroscopy revealed Mg(OH)2stretching vibrations and other functional groups. UV-visible spectroscopy exhibited a red shift (bathochromic effect) in absorption spectra representing the decrease in energy band gap (Eg). Photoluminescence patterns were recorded to study recombination of charge carriers (e-and h+). A significant enhancement in photodegradation efficiency (97.62%) and efficient bactericidal actions against E. coli (14.10 mm inhibition zone) and S. aureus (7.45 mm inhibition zone) were observed for higher doped specimen 4% g-C3N4/St-Mg(OH)2.