Bacteriostatic effect of CoO-TiO2 on Listeria monocytogenes by the presence of the co-catalytic CoO nanoparticles

Antimicrobial Efficacy and Spectrum of Phosphorous-Fluorine Co-Doped TiO2 Nanoparticles on the Foodborne Pathogenic Bacteria Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus

“…Concerning the photocatalytic activity of TiO 2 P25, our results match with the previous results of Long et al [42] as after 30 min incubation a 2 log magnitude decrease in the bacterial count of L. monocytogenes was detected, however this decrease in the living bacterial cell numbers could be further enhanced if the PF-TiO 2 NPs, especially PF-TiO 2 /3 h and PF-TiO 2 /6 h (Figure 2f), were applied in the photocatalytic reaction. In a previous study, doping of TiO 2 with CoO resulted in a <100 log decrease of the L. monocytogenes cells in 24 h when a 4 mg/mL NP suspension was applied at a 10 6 CFU/mL final bacterium concentration [50]. Even though this antimicrobial effect of CoO was revealed both under dark and light conditions, it was undetectable after 6 h exposure.…”

“…These studies focused on the photocatalytic-based antibacterial activity of standard nano-TiO 2 (P25) [42,47,48], or its combination with Ag, an antibacterial metal [43]. Even though the enhanced antibacterial efficacies of TiO 2 NPs doped with other metals and metal oxides, including Cr, Cu, CoO and ZnO, were demonstrated under laboratory conditions [19,[50][51][52][53], their application raises some toxicity issues. Several metals are not only toxic for the bacterial cell, but also for humans and eukaryotic organisms [53][54][55][56][57][58].…”

“…These studies focused on the photocatalytic-based antibacterial activity of standard nano-TiO 2 (P25)[42,47,48], or its combination with Ag, an antibacterial metal[43]. Even though the enhanced antibacterial efficacies of TiO 2 NPs doped with other metals and metal oxides, including Cr, Cu, CoO and ZnO, were demonstrated under laboratory conditions[19,[50][51][52][53], their application raises some toxicity issues. Several metals are not only toxic for the bacterial cell, but also for humans and eukaryotic organisms[53][54][55][56][57][58].In the present study, the most sensitive bacterium species to PF-co-doped TiO 2 NP was the Gram-negative C. jejuni, that was unable to survive at any of the tested NP concentrations (500 µg/mL, 100 µg/mL, 20 µg/mL) during UVA exposure (Figure2a, Supplementary FigureS1a/1-3).…”

A Direct Z-Scheme for the Photocatalytic Hydrogen Production from a Water Ethanol Mixture on CoTiO3/TiO2 Heterostructures

“…The obtained dried mixture was subsequently calcined at 550 °C for 3 h in air to produce CoTiO 3 /TiO 2 composites . In terms of applications, CoTiO 3 /TiO 2 composites have been used for photoelectrochemical water splitting, photocatalytic dye degradation, oxidative dehydrogenation of cyclohexane, dry reforming of methane, peroxymonosulfate activation and metronidazole degradation, resistive humidity sensing, electrochemical sensing of dopamine, and an anode in lithium ion batteries, but surprisingly, CoTiO 3 /TiO 2 composites have not been thoroughly tested as photocatalysts for H 2 production from bioethanol dehydrogenation.…”

Electron Microscopy of TiO2-CoTiO3 based Materials for Photocatalysis

“…CoTiO3-TiO2 materials are not only sunlight active, but also effective to work in Near Infrared (NIR) excitation (1064 nm, equivalent to 1.17 eV or less) taking advantage of most of the sunlight spectrum, from NIR to UV and beyond. The synthesis of these materials is made by chemical methods described elsewhere [2]. Two types of samples are here presented, the as synthesized condition and that after a heat treatment at 500ºC.…”