Dynamic Electron Spring Effect in Hollow Fe <sub>2</sub> O <sub>3</sub> /CoSe <sub>2</sub> Heterostructure Enhance Ethanol Electro‐Oxidation Activity and Stability
Shunlian Ning, Yongqi Jian, Guang‐Qiang Yu, Jinchang Xu, Ming‐Hsien Lee, Dawei Wang, Hongyan Chen, Mihail Bãrboiu, Xiaojun Liu, Dengke Zhao, Linjing Yang, Nan Wang
Abstract
Abstract Developing efficient non‐noble electrocatalysts with high activity and selectivity for ethanol oxidation reaction (EOR) across a wide potential range remains a significant challenge in hybrid energy systems. Herein, hollow Fe 2 O 3 /CoSe 2 heterostructures (H‐Fe 2 O 3 /CoSe 2 @C) via interface engineering are reported as highly effective EOR promising electrocatalysts. Characterizations reveal that Fe 2 O 3 functions as a dynamic electron spring to tune the electronic structure of Co sites, accelerating the formation of the Fe 2 O 3 /CoOOH heterostructure while suppressing Fe 2 O 3 /CoO 2 evolution. In situ Raman spectroscopy and theoretical calculation confirm that the Fe 2 O 3/ CoOOH heterostructure enhances EOR kinetics and lowers the energy barrier of the potential‐determining step. Quasi in situ X‐ray photoelectron spectroscopy further demonstrates that Fe 2 O 3 stabilizes Co 3+ against overoxidation, expanding the operational potential window. Consequently, H‐Fe 2 O 3 /CoSe 2 @C achieves outstanding EOR performance, exhibiting 10 mA cm −2 @1.30 V vs. RHE with a high faradaic efficiency of 99% at 1.30 V. Ethanol‐assisted Zn‐Air battery/water splitting devices based on H‐Fe 2 O 3 /CoSe 2 @C demonstrate enhanced energy conversion efficiency, with voltage reduced by 210 and 180 mV at 10 mA cm −2 , respectively. This work provides critical insights for designing heterostructure electrocatalysts and advancing the utilization of biomass energy.