Modified hydrothermal synthesis and characterization of reduced graphene oxide-silver selenide nanocomposites with enhanced reactive oxygen species generation

A visible-light photocatalyst containing Ag2Se and reduced graphene oxide (RGO) was synthesized by a facile sonochemical-assisted hydrothermal method. X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analysis, and ultraviolet-visible diffuse reflectance spectroscopy results indicated that the RGO-Ag2Se nanocomposite contained small crystalline Ag2Se nanoparticles dispersed over graphene nanosheets and absorbed visible light. The high crystallinity of the nanoparticles increased photocatalytic activity by facilitating charge transport. N2 adsorption-desorption measurements revealed that the RGO-Ag2Se nanocomposite contained numerous pores with an average diameter of 9 nm, which should allow reactant molecules to readily access the Ag2Se nanoparticles. The RGO-Ag2Se nanocomposite exhibited higher photocatalytic activity than bulk Ag2Se nanoparticles to degrade organic pollutant rhodamine B and industrial dye Texbrite BA-L under visible-light irradiation (γ > 420 nm). The generation of reactive oxygen species in RGO-Ag2Se was evaluated through its ability to oxidize 1,5-diphenylcarbazide to 1,5-diphenylcarbazone. The small size of the Ag2Se nanoparticles in RGO-Ag2Se was related to the use of ultrasonication during their formation, revealing that this approach is attractive to form porous RGO-Ag2Se materials with high photocatalytic activity under visible light.

Graphical AbstractA visible-light photocatalyst composed of reduced graphene oxide and Ag2Se nanoparticles is prepared via a facile sonochemical-assisted hydrothermal method. The ability of this photocatalyst to degrade organic dye rhodamine B and industrial dye Texbrite BA-L and generate reactive oxygen species under visible-light irradiation is evaluated.Figure optionsDownload full-size imageDownload as PowerPoint slide