Stabilize the oxygen vacancies in LaFeO3 via altering local electronic structure with CeO2 and WS2 QDs: A novel strategy for achieving durable visible light driven photoinactivation

Abstract

Developing economical and effective water disinfection methods is essential due to the significant health risks posed by microbial contamination, including Staphylococcus epidermidis. This study investigates the potential of CeO₂-LaFeO₃-WS₂ quantum dots (CLW-QDs) nanocomposites (NCs) for photocatalytic inactivation of S. epidermidis. An n-p-n heterostructure NCs was synthesized by a facile method to enhance the photoinactivation efficiency by constructing an interfacial electric field. Engineered oxygen vacancies in LaFeO₃ played a crucial role in trapping excited electrons and reducing charge recombination. The morphology, structural integrity, chemical states, N₂ adsorption properties, and optical characteristics of the fabricated NCs were assessed using SEM, HR-TEM, XRD, XPS, BET, and UV–vis DRS. The constructed interfacial electric field was elaborated by XPS analysis. The recycling ability of NCs was analyzed over six consecutive cycles, confirming structural stability and resistance to photo-corrosion. Reactive oxygen species generation was quantified using scavengers. The NCs' inactivation performance against S. epidermidis was evaluated across a pH range of 4–9. Release of proteins from bacterial cells and possible nucleic acids content were determined during photoinactivation. In addition, SEM analysis was used to validate the loss of cell integrity. Real-time samples of water from a sewage treatment plant were used in photoinactivation investigations and chemical oxygen demand was also evaluated during photoinactivation studies. This comprehensive evaluation highlights the potential of CLW-QDs NCs as an effective photocatalyst for water disinfection.