Constructing Direct Z-Scheme Heterostructure by Enwrapping ZnIn2S4 on CdS Hollow Cube for Efficient Photocatalytic H2 Generation

Rational design hybrid nanostructure photocatalysts with efficient charge separation and transfer, and good solar light harvesting ability have critical significance for achieving high solar-to-chemical conversion efficiency. Here a highly active and stable composite photocatalyst is reported by integrating ultrathin ZnIn2S4 nanosheets on surface of hollow CdS cube to form the cube-in-cube structure. Experimental results combined with density functional theory calculations confirm that the Z-scheme ZnIn2S4/CdS heterojunction is formed, which highly boosts the charge separation and transfer under the local-electric-field at semiconductor/semiconductor interface, and thus prolongs their lifetimes. Moreover, such a structure affords the highly enhanced light-harvesting property. The optimized ZnIn2S4/CdS nanohybrids exhibit superior H-2 generation rate under visible-light irradiation (lambda >= 420 nm) with excellent photochemical stability during 20 h continuous operation.