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.

在不含贵金属的光催化剂上进行水分解生产氢气仍然是一个巨大的挑战。在此，我们提出了在第一时间的2维/二维（2D / 2D）Z-方案的光催化剂在原位上的α-Fe生长的CdS纳米片由形成₂ Ó ₃纳米片。前者还用金属β-NiS助催化剂进行了改性，后者形成了基于欧姆的异质结，并具有氢释放位点的作用。将得到的β-NiS的装饰的CdS /的α-Fe ₂ ö ₃超薄2D / 2D异质结显示出45毫摩尔h的显着的产氢速率^-1 克^-1在420 nm处的量子效率高达46.9％。优良的光催化性能归因于：CdS和（1）之间的亲密和大接口的α-Fe ₂ ö _3个纳米片为易化电荷转移，（2）促进了Z-方案异质结的电荷分离，以及（3）大量的β-NiS金属助催化剂上的欧姆结氢演化位点。总的来说，这项工作表明了通过合理设计和集成二维半导体纳米片上多个内置电场来提高电荷动力学和制氢效率的有前途的策略。