Fine-tuning d-p hybridization in Ni-B<sub>x</sub> cocatalyst for enhanced photocatalytic H<sub>2</sub> production.

Long, Haoyu; Zhang, Xidong; Zhang, Zhenyi; Zhang, Jianjun; Yu, Jiaguo; Yu, Huogen · Nat Commun · 2025

basic_science · Level V

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Abstract

The H<sub>2</sub>-evolution kinetics play a pivotal role in governing the photocatalytic hydrogen-evolution process. However, achieving precise regulation of the H-adsorption and H-desorption equilibrium (H<sub>ads</sub>/H<sub>des</sub>) still remains a great challenge. Herein, we propose a fine-tuning d-p hybridization strategy to precisely optimize the H<sub>ads</sub>/H<sub>des</sub> kinetics in a Ni-B<sub>x</sub> modified CdS photocatalyst (Ni-B<sub>x</sub>/CdS). X-ray absorption fine-structure spectroscopy and theoretical calculations reveal that increasing B-atom amount in the Ni-B<sub>x</sub> cocatalyst gradually strengthens the d-p orbital interaction between Ni<sub>3d</sub> and B<sub>2p</sub>, resulting in a consecutive d-band broadening and controllable d-band center on Ni active sites. The above consecutive d-band optimization allows for precise modulation of the H<sub>ads</sub>/H<sub>des</sub> dynamics in the Ni-B<sub>x</sub>/CdS, ultimately demonstrating a remarkable H<sub>2</sub>-evolution activity of 13.4 mmol g<sup>-1</sup> h<sup>-1</sup> (AQE = 56.1 %). The femtosecond transient absorption spectroscopy further confirms the rapid electron-transfer dynamics in the Ni-B<sub>x</sub>/CdS photocatalyst. This work provides insights into the optimal design of prospective H<sub>2</sub>-evolution catalysts.