Revealing the Importance of Hole Transfer: Boosting Photocatalytic Hydrogen Evolution by Delicate Modulation of Photogenerated Holes

• DOI: 10.1021/acscatal.3c01210
• Publication Date: 2023-06-07T02:46:32Z
• Authors: Yi Li; Shan Yu; Jianglai Xiang; Fengying Zhang; Anqiang Jiang; Yuangang Duan; Chun Tang; Yuehan Cao; Heng Guo; Ying Zhou

Photocatalytic hydrogen evolution (PHE) has gained massive attention for the development of renewable resources. Currently, prominent and stable PHE is still restricted by limited utilization photocatalytic charge carriers, especially holes, which transfer rate approximately two to three orders magnitude slower than that electrons. Although it widely accepted surface holes can be consumed electron donors, rational design photocatalysts speed up hole understand ultrafast photodynamics as well exploration effect oxidation products highly urgent. Herein, cadmium sulfide (CdS), model photocatalyst, investigated based on modulation strategies. To accelerate reaction, H2S-saturated Na2S&Na2SO3 solution, outperforms traditional scavengers, selected remove accumulating photocatalyst surface, while oxidative cocatalyst palladium (PdS) simultaneously impregnated CdS optimize process. Evidenced femtosecond transient absorption spectroscopy (TAS) band structure analysis, process (1–5 ps) related with from PdS proved in CdS/PdS composite. More importantly, density functional theory (DFT) calculation suggests accumulation site also active where species (HS*) adsorbs on. Finally, product composition analyzed through Fourier transform infrared (FTIR) spectroscopy, indicates colorless value-added S2O32– protects light shielding effect. Contributed factors mentioned above, improved efficiency (∼145.9 mmol·g–1·h–1) achieved