Selective-Epitaxial Hybrid of Tripartite Semiconducting Sulfides for Enhanced Solar-to-Hydrogen Conversion.

The design and synthesis of advanced semiconductors is crucial for the full utilization of solar energy. Herein, colloidal selective-epitaxial hybrid of tripartite semiconducting sulfides CuInS 2 Cd(In)SMoS 2 heteronanostructures (HNs) via lateral- and vertical-epitaxial growths, followed by cation exchange reactions, are reported. The lateral-epitaxial CuInS 2 and Cd(In)S enable effective visible to near-infrared (NIR) solar spectrum absorption, and the vertical-epitaxial ultrathin MoS 2 offer sufficient edge sulfur sites for the hydrogen evolution reaction (HER). Furthermore, the integrated structures exhibit unique epitaxial-staggered type II band alignments for continuous charge separation. They achieve the H 2 evolution rate up to 8 mmol h -1 g -1 , which is ≈35 times higher than bare CdS and show no deactivation after long-term cycling, representing one of the most efficient and robust noble-metal-free photocatalysts. This design principle and transformation protocol open a new way for creating all-in-one multifunctional catalysts in a predictable manner.