Photocatalytic action of Ag/TiO2 nanoparticles to emerging pollutants degradation: A comprehensive review

Abstract

Silver (Ag) doped titanium dioxide (TiO2) nanoparticles are promising photocatalysts for the degradation of emerging pollutants. These nanocomposites enhance the photocatalytic activity of TiO2 in visible light, suppress the e-/h+ rearrangement, and enhance their bactericidal properties. This review proposes a bibliometric analysis that elucidates research trends, and important topics on contaminant degradation, analyzes the advantages and limitations of different synthesis techniques (solvothermal, photochemical reduction, sol-gel, and others), their properties to produce Ag/TiO2, and their potential for pollutant degradation. Thus, depending on the technique chosen, Ag doping of TiO2 can offer high stability, recyclability for more than 3 cycles, customized morphologies and sizes, among others. Applications of Ag/TiO2 include wastewater treatment, antibacterial surfaces, food packaging, implants, and others. Advances in the synthesis of Ag/TiO2 photocatalysts offer excellent photocatalytic degradation, between 80 % and 100 %, for organic dyes, hormones, pharmaceuticals, pesticides and other emerging pollutants. Ag/TiO2 photocatalysts show superior degradation rates compared to pure TiO2, with some achieving up to 99 % pollutant removal. The bibliometric analysis performed by Methodi Ordinatio, classifying 267 articles, reveals a foundation of relevant articles, around 35 % of articles published on these topics were published between 2019 and 2021. A complete cost analysis of Ag/TiO2 is considered to determine the feasibility for pilot and large-scale experimentation. These nanocomposites offer a promising solution to address the growing concern about emerging pollutants, disinfection of water, and in the inactivation of pathogenic microorganisms.

Keywords

• Bibliometric analysis
• Nanotechnology
• Visible light
• Photocatalysis
• Water treatment