2D Electron Gas and Oxygen Vacancy Induced High Oxygen Evolution Performances for Advanced Co3O4/CeO2 Nanohybrids
2D Electron Gas and Oxygen Vacancy Induced High Oxygen Evolution Performances for Advanced Co3O4/CeO2 Nanohybrids
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先进 Co3O4/CeO2 纳米杂化物的二维电子气和氧空位诱导的高析氧性能
DOI：
10.1002/adma.201900062
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发表时间：
2019-05-01
影响因子：
29.4
通讯作者：
Dai, Zhihui
中科院分区：
文献类型：
--
作者：
Liu, Ying;Ma, Chao;Dai, Zhihui
在多相纳米杂化物中合理设计原子尺度的界面是开发先进电催化剂的一种诱人而具有挑战性的方法。在此，通过选择具有特定本征特征的两种不同金属氧化物，开发了具有锚定在Co 3 O 4纳米片上的CeO 2纳米立方体的先进Co 3 O 4/CeO 2纳米杂化物（NH），其不仅显示出高的氧空位浓度，而且显示出显著的2D电子气（2DEG）行为，具有近似0.79 +/-0.1过量e（-）/u. c。在Co_3O_4-CeO_2界面的Ce ~（3+）位上。这种2DEG传输通道导致3.8 × 10（14）cm（-2）的高载流子密度和良好的导电性。因此，Co 3 O 4/CeO 2 NHs表现出显着增强的析氧反应（OER）性能，与纯Co 3 O 4和CeO 2的对应物相比，在10 mA cm（-2）下具有270 mV的低过电位和0.25 s（-1）的高转换频率，优于商业IrO 2和一些最近报道的代表性OER催化剂。这些结果证明了通过2DEG工程定制金属氧化物的电催化性能的有效性，在先进的混合纳米结构的设计中向前迈出了一步。
The rational design of atomic-scale interfaces in multiphase nanohybrids is an alluring and challenging approach to develop advanced electrocatalysts. Herein, through the selection of two different metal oxides with particular intrinsic features, advanced Co3O4/CeO2 nanohybrids (NHs) with CeO2 nanocubes anchored on Co3O4 nanosheets are developed, which show not only high oxygen vacancy concentration but also remarkable 2D electron gas (2DEG) behavior with approximate to 0.79 +/- 0.1 excess e(-)/u.c. on the Ce3+ sites at the Co3O4-CeO2 interface. Such a 2DEG transport channel leads to a high carrier density of 3.8 x 10(14) cm(-2) and good conductivity. Consequently, the Co3O4/CeO2 NHs demonstrate dramatically enhanced oxygen evolution reaction (OER) performances with a low overpotential of 270 mV at 10 mA cm(-2) and a high turnover frequency of 0.25 s(-1) when compared to those of pure Co3O4 and CeO2 counterparts, outperforming commercial IrO2 and some recently reported representative OER catalysts. These results demonstrate the validity of tailoring the electrocatalytic properties of metal oxides by 2DEG engineering, offering a step forward in the design of advanced hybrid nanostructures.