Photocatalytic properties of Ag–AgBr nanostructures in ion-exchanged layers of bromide sodium-zinc-aluminosilicate glass matrix

Abstract

The photocatalytic properties of Ag–AgBr nanostructures formed by low-temperature ion exchange method and followed heat-treatment in bromide sodium-zinc-aluminosilicate glass have been investigated. Glasses based on Na2O–ZnO–Al2O3–SiO2 system and doped with Sb2O3, Ce2О3 and Br were synthesized. Layers containing silver ions were formed on the surface of sodium-zinc-aluminosilicate glass by the ion exchange method. The glass samples were immersed in a bath containing a melt of nitrate mixture 5AgNO3/95NaNO3 (mol%) at 320 °C for 2 hours. Subsequent heat treatment at 500 °C resulted in a formation of Ag–AgBr nanostructures in the surface layer. The photocatalytic properties of the Ag–AgBr nanostructures on the glass surface were measured by the decomposition of the methyl orange dye. A comprehensive study of the spectral and photocatalytic properties of Ag–AgBr nanostructures has been carried out. It was shown that, after ion exchange and heat treatment, the AgBr crystal shells with a size of 6 nm were formed around silver nanoparticles. It has been established that the presence of a photocatalyst with Ag–AgBr nanostructures in the surface layer of glass under ultraviolet irradiation leads to degradation of the methyl orange dye by 77 %. Reducing the thickness of the ion-exchange layer to 5 μm by chemical etching decreased the degradation efficiency of the methyl orange dye to 15 %. The results of the work can be applied in devices for the photocatalytic decomposition of water to produce hydrogen.

Keywords

• ion exchange
• bromide sodium-zinc-aluminosilicate glass
• silver nanoparticles
• agbr nanocrystals
• photocatalysis
• methyl orange dye