Photocatalytic activity of silica and silica-silver nanocolloids based on photo-induced formation of reactive oxygen species

Abstract Semiconductor nanomaterials are often proposed as photocatalysts for wastewater treatment; silica still largely unexploited because their photocatalytic performances need improvements, especially under visible light. The present study is a proof-of-concept that amorphous colloids once submitted to the proper surface modifications change into an efficient photocatalyst even low-energy illumination source. For this reason, silica-based colloidal nanomaterials, such bare (SiO 2 NPs), aminated (NH -SiO and Ag NPs-decorated (Ag-SiO NPs) silica, tested degradation of 9-anthracenecarboxylic acid (9ACA), taken model aromatic compound. Interestingly, upon irradiation at 313 nm, NH NPs induce 9ACA degradation, effect improved when Ag-SiO used. On other hand, 405 nm activates plasmon photocatalyst, providing faster more photodegradation. photodegradation experiments also performed white light illumination, employing low-intensity fluorescent lamp, confirming satisfying efficiencies. catalytic SiO -based nanoparticles thought originate from photo-excitable defects NP plasmons since takes place only adsorbed on surface. In addition, involvement reactive oxygen species was demonstrated through scavenger use, obtaining yield 17%. conclusion, work shows applicability defects, can act with monochromatic Graphic abstract Silica Ag-decorated photosensitize formation Reactive Oxygen Species 17% ROS able oxidase pollutants chemi-adsorbed colloids. Silica-silver nanocomposites activity useful degrade compounds.