TY - JOUR
T1 - Substrate-Mediated Boosting of the Co3+/Co2+Pair for Highly Active and Durable Oxygen Evolution Electrocatalysis
AU - Xu, Jing
AU - Zheng, Jinou
AU - Yang, Tao
AU - Wu, Zhonghuai
AU - Li, Sai
AU - Xiao, Chen
AU - Wang, Xin
AU - Wang, Yang
AU - Xie, Shouyi
AU - Tan, Hao
AU - Zhou, Zheng
N1 - Publisher Copyright:
© 2026 American Chemical Society
PY - 2026/2/25
Y1 - 2026/2/25
N2 - Boosting the trivalent/divalent metal (M3+/M2+) redox pair in 3d metal compounds (TMCs) can facilitate the surface reconstruction during the oxygen evolution reaction (OER), transforming TMCs into trivalent metal oxyhydroxide (MOOH) species, which has been demonstrated to be the essential phase of the active substance. Herein, we examined an indirect strategy by the proof-of-concept of cobalt phosphide (CoP), that is, leveraging the strong substrate effect of Ti3C2Tx MXene to boost the Co3+/Co2+ pair, validated by X-ray absorption near-edge spectroscopy (XANES). The resulting CoP@Ti3C2Tx electrocatalyst achieves an ultralow overpotential of 218 mV at 10 mA cm–2 and a small Tafel slope of 52 mV dec–1 on the glassy carbon electrode and can operate stably over 500 h in a water electrolyzer, outperforming most non-noble metal electrocatalysts. Operando attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), operando Raman spectra, and theoretical calculations reveal an adsorbate evolution mechanism (AEM) for CoP@Ti3C2Tx, suggesting the high activity typically associated with lattice oxygen-mediated mechanism (LOM) catalysts while inheriting the excellent stability of AEM-driven systems. This work highlights substrate engineering as an effective indirect strategy to boost the M3+/M2+ pair, providing a paradigm for designing OER electrocatalysts with both high activity and long-term stability.
AB - Boosting the trivalent/divalent metal (M3+/M2+) redox pair in 3d metal compounds (TMCs) can facilitate the surface reconstruction during the oxygen evolution reaction (OER), transforming TMCs into trivalent metal oxyhydroxide (MOOH) species, which has been demonstrated to be the essential phase of the active substance. Herein, we examined an indirect strategy by the proof-of-concept of cobalt phosphide (CoP), that is, leveraging the strong substrate effect of Ti3C2Tx MXene to boost the Co3+/Co2+ pair, validated by X-ray absorption near-edge spectroscopy (XANES). The resulting CoP@Ti3C2Tx electrocatalyst achieves an ultralow overpotential of 218 mV at 10 mA cm–2 and a small Tafel slope of 52 mV dec–1 on the glassy carbon electrode and can operate stably over 500 h in a water electrolyzer, outperforming most non-noble metal electrocatalysts. Operando attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), operando Raman spectra, and theoretical calculations reveal an adsorbate evolution mechanism (AEM) for CoP@Ti3C2Tx, suggesting the high activity typically associated with lattice oxygen-mediated mechanism (LOM) catalysts while inheriting the excellent stability of AEM-driven systems. This work highlights substrate engineering as an effective indirect strategy to boost the M3+/M2+ pair, providing a paradigm for designing OER electrocatalysts with both high activity and long-term stability.
KW - Co/Cometal pair
KW - indirect modulation strategy
KW - oxygen evolution reaction
KW - substrate engineering
KW - water electrolyzer
UR - https://www.scopus.com/pages/publications/105030922961
U2 - 10.1021/acsami.5c24395
DO - 10.1021/acsami.5c24395
M3 - Article
AN - SCOPUS:105030922961
SN - 1944-8244
VL - 18
SP - 11457
EP - 11466
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 7
ER -