Constructing CoP/Ni2P Heterostructure Confined Ru Sub‐Nanoclusters for Enhanced Water Splitting in Wide pH Conditions

• Published in: Advanced science Vol. 11; no. 35; pp. e2401398 - n/a
• Main Authors: Zhang, Huimin, Liu, Wenhao, Li, Zhenhao, Qiao, Liang, Chi, Kebin, Guo, Xiaoyan, Cao, Dong, Cheng, Daojian
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.09.2024; John Wiley and Sons Inc; Wiley
• Subjects: Adsorption; alkaline water electrolyzer; Carbon; Cobalt; Electrons; heterojunction; interface confinement; Interfaces; Metals; Microscopy; Morphology; Nickel; Oxidation; Ru‐CoP/Ni2P; water splitting
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202401398

Developing efficient electrocatalysts for water splitting is of great significance for realizing sustainable energy conversion. In this work, Ru sub‐nanoclusters anchored on cobalt‐nickel bimetallic phosphides (Ru‐CoP/Ni2P) are constructed by an interfacial confinement strategy. Remarkably, Ru‐CoP/Ni2P with low noble metal loading (33.1 µg cm−2) shows superior activity for hydrogen evolution reaction (HER) in all pH values, whose turnover frequency (TOF) is 8.7, 15.3, and 124.7 times higher than that of Pt/C in acidic, alkaline, and neutral conditions, respectively. Meanwhile, it only requires the overpotential of 171 mV@10 mA cm−2 for oxygen evolution reaction (OER) and corresponding TOF is 20.3 times higher than that of RuO2. More importantly, the Ru‐CoP/Ni2P||Ru‐CoP/Ni2P displays superior mass activity of 4017 mA mgnoble metal−1 at 2.0 V in flowing alkaline water electrolyzer, which is 105.1 times higher than that of Pt/C||IrO2. In situ Raman spectroscopy demonstrates that the Ru sites in Ru‐CoP/Ni2P play a key role for water splitting and follow the adsorption evolution mechanism toward OER. Further mechanism studies disclose the confined Ru atom contributes to the desorption of H2 during HER and the formation of O‐O bond during OER, leading to fast reaction kinetics. This study emphasizes the importance of interface confinement for enhancing electrocatalytic activity. The Ru sub‐nanoclusters confined on the CoP/Ni2P herterogenous structure show superior electrocatalytic performance for pH‐universal HER and alkaline OER. In situ Raman and DFT calculations reveal that the confinement effect endows superior intrinsic activity to Ru‐CoP/Ni2P, and the active Ru sites contributes to the desorption of H2 for HER and promoting the transformation of O* to OOH* for OER.