Silver chlorobromidenanoparticles with highly pure phases: synthesis and characterization

Abstract

Ternary silver chlorobromide (AgCl_xBr_1−x) nanoparticles with finely tuned compositions have been successfully synthesized through a co-precipitation approach in which silver nitrate reacts with hexadecyltrimethylammonium chloride (CTAC) and hexadecyltrimethylammonium bromide (CTAB) in aqueous solutions at room temperature. The synthesized AgCl_xBr_1−x nanoparticles exhibit highly pure crystalline phases with face-centred cubic symmetries and compositional purity without contamination of optically active silver clusters and silver nanodomains. Such high purity enables the determination of indirect bandgap energies of the AgCl_xBr_1−x nanoparticles for the first time. Tuning the composition from chloride- to bromide-rich leads to a decrease in size and the indirect bandgap of the nanoparticles. In addition, preliminary evaluations indicate that the ternary AgCl_xBr_1−x nanoparticles are better in the photocatalytic decomposition of methylene blue molecules with visible light in comparison with the counterpart binary AgCl and AgBr nanoparticles.