Enhanced Spin‐Polarized Electric Field Modulating p‐Band Center on Ni‐Doped CdS for Boosting Photocatalytic Hydrogen Evolution

Abstract

It is a challenge to regulate charge separation dynamics and redox reaction kinetics at the atomic level to synergistically boost photocatalytic hydrogen (H2) evolution. Herein, a robust Ni‐doped CdS (Ni‐CdS) photocatalyst is synthesized by incorporating highly dispersed Ni atoms into the CdS lattice in substitution for Cd atoms. Combined characterizations with theoretical analysis indicate that local lattice distortion and S‐vacancy of Ni‐CdS induced by Ni incorporation lead to an increased dipole moment and enhanced spin‐polarized electric field, which promotes the separation and transfer of photoinduced carriers. In this contribution, charge redistribution caused by enhanced internal electric field results in the downshift of the S p‐band center, which is conducive to the desorption of intermediate H* for boosting the H2 evolution reaction. Accordingly, the Ni‐CdS photocatalyst shows a remarkably improved photocatalytic performance with an H2 evolution rate of 20.28 mmol g−1 h−1 under visible‐light irradiation, which is 5.58 times higher than that of pristine CdS. This work supplied an insightful understanding that the enhanced polarization electric field governs the p‐band center for efficient photocatalytic H2 evolution activity.