Concaving AgI sub-microparticles for enhanced photocatalysis

•Concave AgI nanoparticles have been synthesized for the first time.•Concave AgI nanoparticles exhibit a much higher efficiency in photocatalysis.•Concaving particles benefit adsorption capacity and interfacial electron transfer.•The surfaces in concave AgI nanoparticles are different from those in spherical AgI nanoparticles.

Concave particles represent a new class of structures with their surfaces curving in or hollowed inward and thus presence of regions with negative curvatures. Owing to the potential high-index facets and negative curvatures, crystalline particles with concave surfaces are expected to show unexplored or substantially enhanced performance in comparison with the counterpart particles with convex surfaces. In this report, we highlight a facile approach for the first-time synthesis of concave AgI nanoparticles through a controlled etching of spherical AgI particles in a solution containing ethylenediamine, absolute alcohol, and polyvinylpyrrolidone. Physical parameters including morphology and size of the resulting concave AgI particles can be tuned by carefully controlling the reaction conditions such as the amount of precursors and the injection rate of precursor solutions. Most importantly, the concave AgI particles exhibit a much higher efficiency towards photocatalytic degradation of organic molecules than the corresponding spherical AgI particles. The as-synthesized concave AgI particles are expected to be useful not only for the fundamental investigation on shape- and composition-dependent properties but also for potential applications in photocatalysis, electrocatalysis, photonics, etc.

Graphical abstractConcave AgI nanoparticles have been synthesized through controlled etching of spherical AgI particles. The concave particles exhibit a much higher photocatalytic activity than the spherical ones towards degradation of organic pollutant.Figure optionsDownload full-size imageDownload as PowerPoint slide