CeO2-Induced Interfacial Co2+ Octahedral Sites and Oxygen Vacancies for Water Oxidation
CeO2-Induced Interfacial Co2+ Octahedral Sites and Oxygen Vacancies for Water Oxidation
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DOI：
10.1021/acscatal.9b01819
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发表时间：
2019-07-01
期刊：
影响因子：
12.9
通讯作者：
Chai, Yang
中科院分区：
文献类型：
--
作者：
Qiu, Bocheng;Wang, Cong;Chai, Yang
电催化析氧反应（OER）是电化学能量转换和储存的关键过程.含钴尖晶石氧化物是OER的有希望的候选者，但由于尖晶石结构的高稳定性和可逆性，在OER期间遭受阳离子缺乏。在这里，我们联合收割机催化惰性CeO 2和尖晶石结构Co 3 O 4（CeO 2/Co 3 O 4）通过内置的p-n异质结。强耦合的p-n异质结界面允许从CeO 2到Co 3 O 4的快速界面电荷转移，这导致高浓度的氧空位和由CeO 2/Co 3 O 4界面处的Co 3+（O-h）还原产生的Co2+八面体（Co2+（O-h））位点。结果表明，在Ce/Co最佳配比下制备的CeO 2/Co 3 O 4界面具有较高的OER活性，在10 mA cm（-2）电流密度下的过电位仅为265 mV，Tafel斜率为68.1 mV dec（-1），并且在碱性介质中具有较长的使用寿命。
Electrocatalytic oxygen evolution reaction (OER) is a key process in electrochemical energy conversion and storage. Cobalt-containing spinel oxides are promising candidates for OER, but suffer from cation deficiency during OER, because of the high stability and reversibility of the spinel structure. Herein, we combine catalytically inactive CeO2 and spinel structure Co3O4 (CeO2/Co3O4) by a built-in p-n heterojunction. The strongly coupled p-n heterojunction interface allows a rapid interfacial charge transfer from CeO2 to Co3O4, which leads to a high concentration of oxygen vacancies and the generation of Co2+ octahedral (Co2+(O-h)) sites from the reduction of Co3+(O-h) at the CeO2/Co3O4 interface. Consequently, the CeO2/Co3O4 interface with the optimal ratio of Ce/Co exhibits high OER activity with an overpotential of only 265 mV at the current density of 10 mA cm(-2), a Tafel slope of 68.1 mV dec(-1), and long-term durability in an alkaline medium.