Dye Degradation, Antimicrobial Activity, and Molecular Docking Analysis of Samarium-Grafted Carbon Nitride Doped-Bismuth Oxobromide Quantum Dots

Abstract

Various concentrations of samarium-grafted-carbon nitride (Sm-g-C₃N₄) doped-bismuth oxobromide (BiOBr) quantum dots (QDs) are prepared by the co-precipitation method. Elemental evaluation, morphological, optical, and functional group assessment are studied employing characterization techniques. Based on the XRD pattern analysis, it is determined that BiOBr exhibits a tetragonal crystal structure. The electronic spectroscopy revealed an absorption peak for BiOBr at 315 nm and the bandgap energy (E_g) decreasing from 3.9 to 3.8 eV with the insertion of Sm-g-C₃N₄. The presence of vibrational modes related to BiOBr at 550 cm⁻¹ is confirmed through FTIR spectra. TEM revealed that pure BiOBr possessed non-uniform QDS, and agglomeration increased with the addition of Sm-g-C₃N₄. The catalytic performance of Sm-g-C₃N₄ into BiOBr (6 mL) in a neutral medium toward rhodamine B exhibited excellent results (99.66%). The bactericidal activity is evaluated against multi-drug resistance (MDR) Escherichia coli once the surface area is increased by dopant and the measured inhibition zone is assessed to be 3.65 mm. Molecular docking results supported the in vitro bactericidal potential of Sm-g-C₃N₄ and Sm-g-C₃N₄ doped-BiOBr as DNA gyrase_{E. coli} inhibitors. This study shows that the novel Sm-g-C₃N₄ doped-BiOBr is a better catalyst that increases specific semiconductor's catalytic activity (CA).