Constructing Direct Z-Scheme Heterostructure by Enwrapping ZnIn2 S4 on CdS Hollow Cube for Efficient Photocatalytic H2 Generation

Adv Sci (Weinh). 2022 Aug;9(24):e2201773. doi: 10.1002/advs.202201773. Epub 2022 Jun 24.

Abstract

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 ZnIn2 S4 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 ZnIn2 S4 /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 ZnIn2 S4 /CdS nanohybrids exhibit superior H2 generation rate under visible-light irradiation (λ ≥ 420 nm) with excellent photochemical stability during 20 h continuous operation.

Keywords: ZnIn2S4/CdS heterostructure; density functional theory; direct Z-scheme junction; hollow CdS cube; photocatalytic H2 generation.