Photoinduced Oxygen Species Construct Pt–O Active Sites: Enhancing Proton Transport Dynamics for Efficient Hydrogen Electrode Reactions

In the realm of water electrolysis catalysts, supported platinum‐based catalysts have consistently exhibit superior catalytic activity. However, the catalytic mechanisms of platinum species with varying oxidation states, particularly the higher oxidation states, remain elusive. Herein, an UV light induced reactive oxygen species (ROS) strategy is developed to construct uniformly dispersed PtOx nanoclusters on nitrogen‐doped hollow carbon spheres (PtOx/NHCS). The in‐situ Raman spectroscopy and density functional theory (DFT) calculations reveal that the nitrogen‐doped carbon matrix optimizes the proton transfer pathways through the adsorption of oxygen‐containing species. Additionally, the unique electronic structure of the Pt–O units in the PtOx clusters accelerated the transformation of proton adsorption and desorption capabilities at the active sites. Therefore, the engineered catalyst demonstrates exceptional bifunctionality for hydrogen electrode reactions, delivering HER current density of 10 mA cm −2 with ultralow overpotentials of 17 mV (alkaline) and18 mV (acidic) while simultaneously achieving superb HOR mass activity of 1345.56 mA mg −1 Pt at η = 50 mV. Meanwhile, the observed kinetic reciprocity between HER and HOR operations provides compelling evidence for the possibility of the proton transfer mechanism.