Lead Chalcohalides Nanocrystals Superlattices and Their Application as Electrocatalysts

Here we report the synthesis of colloidal lead chalcohalides (Pb4S3Br2​) nanocrystals, which represent a stable derivative of lead halide nanocrystals. The size of the Pb4S3Br2 nanocrystals can be precisely controlled within the range of 8 to 15 nm, achieving an accuracy of approximately 1 nm through the regulation of reaction temperature. These nanocrystals can further self‐assemble into well‐ordered superlattices, exhibiting a dense hexagonal stacking in x‐y direction, and a lamellar structure for each layer in z direction. The Pb4S3Br2​ nanocrystals superlattice films exhibit remarkable electrocatalytic activity in the oxygen evolution reaction (OER) and maintain their size and morphology well after multiple cycles as a catalyst in seawater.