Innovative Ti_1–<i>x</i>Nb_<i>x</i>N–Ag Films Inducing Bacterial Disinfection by Visible Light/Thermal Treatment

This study presents innovative Ti_1–<i>x</i>Nb_<i>x</i>N–Ag films obtained by a suitable combination of low-energy and high-energy sputtering leading to bacterial inactivation. The bacterial inactivation kinetics by the TiNbN layers was drastically enhanced by the addition of 6–7% Ag and proceeded to completion within 3 h after the film autoclaving. By X-ray photoelectron spectroscopy (XPS), the samples after autoclaving presented in their upper layers TiO₂, Nb₂O₅ and Ag₂O with a surface composition of Ti_0.81Nb_0.19N_0.99Ag_0.068. Surface potential/pH changes in the Ti_1–<i>x</i>Nb_<i>x</i>N–Ag films were monitored during bacterial inactivation. Surface redox processes during the bacterial inactivation were detected by XPS. The diffusion of Ag in the Ti_1–<i>x</i>Nb_<i>x</i>N–Ag films was followed at 50 and 70 °C pointing. The beneficial thermal treatment points out to the bifunctional bacterial inactivation properties of these films and their potential application in healthcare facilities. Interfacial charge transfer (IFCT) under light irradiation between Ag₂O, Nb₂O₅ and TiO₂ is suggested consistent with the data found during the course of this study. The TiO₂/Nb₂O₅ lattice mechanism is discussed in the framework of the Verwey’s controlled valence model. The surface properties of the Ti_1–<i>x</i>Nb_<i>x</i>N–Ag films were investigated by X-ray diffraction, atomic force microscopy, and scanning electron microscopy

Visible light responsive AgBiS₂ nanomaterials for photocatalytic applications in removal of antimicrobial compounds and bacterial pathogens: Possible electrochemical pathways

Potential synthesis of ternary chalcogenide nanocomposite to showcase a practical electronic pathway to improve photocatalytic efficiency was carried out. In the present study, AgBiS2 nanorod-shaped with remarkably visible-light absorption was prepared using solvothermal techniques. This material was employed in photocatalytic degradation of amoxicillin (AMX) under visible light irradiation. The results indicated more than 90% degradation of AMX under 60 min having a corresponding bandgap of ∼2.19 eV. In the verge of understanding the photogenerated separation of electron-hole pair, VB and CB potentials were calculated to be 2.06 eV and − 0.76 eV, proposing a possible pathway for the degradation study. The photogenerated intermediates were identified using LC-MS analysis and the mineralization was followed using TOC analysis. A scavenging experiment showed a potential reactive oxygen species involved in the oxidation of organics that proved effective in three consecutive trials.In addition, antibacterial and antibiofilm activity showcased fair efficiency of the material, especially the presence of Ag+ in AgBiS2 improves antimicrobial activity. In case of antibiofim activity, 4 × 107 CFU/mL were seen to be most effective for the biomass formation of the biofilms.</p