题目： | Dimensional Regulation of Monoclinic Phase Iridium Dioxide Switches the Mechanism for Acid Water Oxidation |
作者： | Sihui Pan1, Hanzhuo Luo1,2, Penghao Li1, Chenchen Li2, Long Chen2, Wei-Hsiang Huang3, Chih-Wen Pao3, Youyong Li1, Zhiwei Hu4, Yujin Ji, 1* Mingwang Shao, 1* and Qi Shao2 |
单位： | 1Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, China 2College of Chemistry , Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123, China 3National Synchrotron Radiation Research Centre, 101 Hsin-Ann Road, Hsinchu 30076, Taiwan 4Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Street 40 01187, Dresden, Germany |
摘要： | Electrochemical water splitting represents a promising strategy for hydrogen production, with oxygen evolution reaction (OER) being a critical half-reaction. Iridium dioxide (IrO2) is an advanced OER catalyst owing to excellent stability. However, regulating key intermediates and decreasing reaction barriers remain great challenges. Here, 2D metastable-phase IrO2 nanosheet (M-IrO2 NS) by a mixed molten salt method is reported. M-IrO2 NS exhibits a 3% compressive strain along the a-axis (a = 4.30 & Aring; vs 4.43 & Aring;) compared to 1D metastable-phase IrO2 nanoribbon (M-IrO2 NR). In 0.5 M H2SO4, M-IrO2 NS exhibits a low overpotential of 186 mV at 10 mA cm-2 and a high mass activity of 2071.8 mA mgIr -1 at 1.5 V versus reversible hydrogen electrode (RHE). When integrated into a proton exchange membrane water electrolysis (PEMWE), M-IrO2 NS maintains a current density of 2.83 A cm-2 at 1.8 V for 1600 h without degradation. Mechanistic investigations reveal a transition from adsorbate evolution mechanism (AEM) in M-IrO2 NR to oxide pathway mechanism (OPM) in M-IrO2 NS, confirmed by the Fourier transform infrared measurements, density-functional-theory calculations and mass spectrometry measurements. This study demonstrates the impact of dimensional regulation on optimizing the OER and provides a new platform for electrocatalyst development. |
影响因子： | 18.5 |
分区情况： | 一区 |
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责任编辑：郭佳