Hollow AgI:Ag Nanoframes as Solar Photocatalysts for Hydrogen Generation from Water Reduction

A facile strategy based on the principle of the Kirkendall effect has been developed to synthesize hollow nanoframes and nanoshells of AgI:Ag composites through the controlled anion-exchange reaction between I- ions and solid AgBr:Ag (or AgCl:Ag) nanoparticles that serve as templates. Regardless of the morphologies of the template nanoparticles, they can be chemically transformed to hollow AgI: Ag structures with morphologies similar to those of the templates. The synthesized hollow AgI: Ag nanostructures can be used as efficient photocatalysts for H-2 generation from water reduction and the decomposition of organic pollutants owing to the enhanced absorption of visible light by the Ag components in the hybrid nanostructures. The hollow nanostructures exhibit a higher photocatalytic performance than the corresponding solid nanoparticles possibly because of the large surface area and unique AgI/Ag interfaces associated with the hollow nanostructures.