Chemical synthesis of silver/titanium dioxide nanoheteroparticles for eradicating pathogenic bacteria and photocatalytically degrading organic dyes in wastewater

Abstract

Titanium dioxide photocatalysis is a promising technology for the treatment of pollutants in wastewater. However, it remains challenging to overcome its inherent drawbacks, such as a high recombination rate of photogenerated charges and low solar-energy utilization. Herein, Ag/TiO 2 nanoheteroparticles (ATNs) were synthesized using a modified deposition method, and their physical, chemical, antibacterial, and photocatalytic properties were subsequently analyzed. The ATNs with 8 wt% Ag deposition exhibited an excellent antibacterial activity. For Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans, the minimum inhibitory concentrations of ATNs were 250.00, 62.50, 125.00, 250.00, and 62.50 mg/L, whereas the minimum bactericidal concentrations were 250.00, 1000.00, 125.00, 250.00, and 1000.00 mg/L, respectively. The antibacterial activity of the ATNs could be correlated to the amount of Ag deposition. Furthermore, the ATNs with 3 wt% Ag deposition showed 90.1% rhodamine B degradation under simulated sunlight conditions in 90 min. The optimum Ag deposition of 8 wt% effectively promoted the efficient separation of optical charges and improved the photocatalytic properties of the catalyst. Therefore, the ATN composite materials can eliminate pathogenic bacteria and degrade organic pollutants in wastewater. The synthesized ATNs exhibit significant application potential in the field of wastewater treatment.