Efficient Electro-Oxidation of Water near Its Reversible Potential by a Mesoporous IrOx Nanoparticle Film
Efficient Electro-Oxidation of Water near Its Reversible Potential by a Mesoporous IrOx Nanoparticle Film
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DOI：
10.1021/jp9060076
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发表时间：
2009-07-30
影响因子：
3.7
通讯作者：
Murray, Royce W.
中科院分区：
文献类型：
--
作者：
Nakagawa, Takaaki;Beasley, Christopher A.;Murray, Royce W.
我们描述了形成稳定的，粘附性，介孔膜的2 nm直径（IrOx）-O-IV纳米粒子的玻碳电极上，由以前未报道的方法控制电位电絮凝从pH 13的纳米粒子溶液。这些膜引发从水氧化的O-2释放，然后实现100%的电流效率，在过电位仅类似于0.15和类似于0.25 V，分别高于可逆的H2O/O-2电位。在类似于0.5 mA/cm（2）的条件下测量的过电位与pH值无关，并且是电化学水氧化的最小值，这是电化学太阳能电池中可能使用的重要特性。薄膜似乎是介孔和微观访问，因为O-2的演变电流增加成比例的多层纳米粒子膜的覆盖率，但没有同时增加过电位。
We describe the formation of stable, adherent, mesoporous films of 2 nm diameter (IrOx)-O-IV nanoparticles on glassy carbon electrodes, by a previously unreported method of controlled potential electro-flocculation from pH 13 nanoparticle solutions. These films initiate O-2 evolution from water oxidation and then achieve 100% current efficiency, at overpotentials only similar to 0.15 and similar to 0.25 V higher, respectively, than the reversible H2O/O-2 potential. The overpotentials, measured at similar to 0.5 mA/cm(2), are independent of pH and are the smallest yet reported for electrochemical water oxidation, a property important in possible uses in electrochemical solar cells. The films appear to be mesoporous and microscopically accessible, since O-2 evolution currents increase proportionately to multilayer nanoparticle film coverage but without a concurrent increase in overpotential.