Pulsed laser-assisted synthesis of nano nickel(ii) oxide-anchored graphitic carbon nitride: Characterizations and their potential antibacterial/anti-biofilm applications

Nickel(ii) oxide-graphitic carbon nitride (n-NiO@g-C3N4) nanocomposite, in which nickel oxide nanoparticles (n-NiO) are anchored on the polymeric surface of graphitic carbon nitride (g-C3N4), was synthesized using the pulsed laser post processing (PLPP) in liquid medium. In the PLPP method, the precursors (NiO and g-C3N4) were simultaneously subjected to pulsed laser-induced fragmentation, and pulsed laser-induced defect engineering (anchoring of NiO on g-C3N4). To optimize the functionality of the material, n-NiO@g-C3N4 with four different mass contents of n-NiO was synthesized. The synthesized n-NiO@g-C3N4 nanocomposite and its composite partners (n-NiO and g-C3N4) were structurally, morphologically, elementally characterized by X-ray diffraction, filed emission scanning electron microscope, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analyses. As a first anti-microbial application, n-NiO@g-C3N4 was used to evaluate the minimal inhibitory concentration and minimal bactericidal concentration against the gram-positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa bacteria. As a second anti-microbial application, the efficacy of n-NiO@g-C3N4 nanocomposite to retard S. aureus and P. aeruginosa biofilms' growth was evaluated. It was found that for both applications, n-NiO@g-C3N4 nanocomposite exhibited an excellent anti-bacterial activity compared to pure g-C3N4.