Integrating 2D/2D CdS/α-Fe2O3 ultrathin bilayer Z-scheme heterojunction with metallic β-NiS nanosheet-based ohmic-junction for efficient photocatalytic H2 evolution

By Rongchen Shen, Liping Zhang, Xingzhu Chen, M. Jaroniec, Neng Li, Xin Li. 2020

218 citations recorded by the source corpus.

Abstract Water splitting for hydrogen production on noble metal-free photocatalysts remains a big challenge. Herein, we present for the first time a 2-dimensional/2-dimensional (2D/2D) Z-scheme photocatalyst formed by in situ growing CdS nanosheets on α-Fe2O3 nanosheets. The former was additionally modified with metallic β-NiS cocatalyst, which creates a Ohmic-based heterojunction and functions as hydrogen-evolution sites. The resultant β-NiS-decorated CdS/α-Fe2O3 ultrathin 2D/2D heterojunction showed a remarkable hydrogen production rate of 45 mmol h−1 g−1 and a high quantum efficiency of 46.9 % at 420 nm. The excellent photocatalytic performance is attributed to: (1) intimate and large interfaces between CdS and α-Fe2O3 nanosheets for facilitated charge transfer, (2) promoted charge separation in the Z-scheme heterojunction, and (3) large quantity of Ohmic-junction hydrogen-evolution sites over metallic β-NiS cocatalyst. Overall, this work demonstrates a promising strategy for improving charge dynamics and hydrogen-production efficiency, through rational design and integration of multiple built-in electric fields over 2D semiconductor nanosheets.

Subfields: Materials Chemistry, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/e811488b2b98d1de9f1f7e2143999f20fd41c420