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Updated: Oct 25, 2026

A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions
Published on: August 17, 2016
Dual-Optimized Medium-Entropy Alloy Heterojunction: Synergistically Enhancing Surface Kinetics and Interfacial Mass
Minghui Hao1, Chunlei Chang1, Chunhu Li1
1Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao266100, China.
Abstract:
To address the prominent "bubble shielding" effect at high current densities during hydrazine oxidation reaction (HzOR) as a replacement for the traditional oxygen evolution reaction (OER), this study successfully designed a medium-entropy heterojunction electrocatalyst (Co0.226Fe0.277Ni0.209Mo0.288/MoS2/CC) featuring discontinuous three-phase contact lines through a topological transformation strategy. The catalyst exhibits unique superwetting properties (superhydrophilic/superaerophobic), significantly enhancing bubble detachment efficiency during gas evolution. In situ microscopic observations reveal that the bubble sizes released from the surface are markedly smaller than those form Pt/C/CC under current densities of 10 and 100 mA cm-2. In addition, the Co0.226Fe0.277Ni0.209Mo0.288/MoS2/CC achieves dual optimization of reaction kinetics and interfacial mass transfer through the synergistic effect of enhanced N2H4 adsorption capacity and reduced H* desorption energy barrier, achieves outstanding bifunctional performance in hydrazine-assisted water electrolysis system, requiring overpotential of only 28 mV for HER and work-potential of -6 mV for HzOR to reach a current density of 10 mA cm-2. Furthermore, a membrane-free overall hydrazine splitting (OHzS) system with Co0.226Fe0.277Ni0.209Mo0.288/MoS2/CC as an electrode requires only 0.247 V to deliver 100 mA cm-2. This work provides novel insights for designing efficient and stable gas-evolving electrocatalysts, contributing significantly to advancing sustainable energy conversion technologies.
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