Silver chlorobromide nanoparticles with highly pure phases: Synthesis and characterization

Ternary silver chlorobromide (AgClBr) 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 AgClBr 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 AgClBr 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 AgClBr nanoparticles are better in the photocatalytic decomposition of methylene blue molecules with visible light in comparison with the counterpart binary AgCl and AgBr nanoparticles. © 2013 The Royal Society of Chemistry.