CoSex nanocrystalline-dotted CoCo layered double hydroxide nanosheets: a synergetic engineering process for enhanced electrocatalytic water oxidation
CoSex nanocrystalline-dotted CoCo layered double hydroxide nanosheets: a synergetic engineering process for enhanced electrocatalytic water oxidation
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CoSex 纳米晶点状 CoCo 层状双氢氧化物纳米片：增强电催化水氧化的协同工程工艺
DOI：
10.1039/c7nr05867e
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发表时间：
2017
期刊：
影响因子：
6.7
通讯作者：
Honggang Fu
中科院分区：
文献类型：
--
作者：
Yuzhu Xue;Zhiyu Ren;Ying Xie;Shichao Du;Jun Wu;Huiyuan Meng;Honggang Fu
控制钴基（氢）氧化物的导电性和形貌对于优化析氧反应（OER）中的能量转换具有重要意义。本文采用改进的原位还原法和界面定向组装法，在惰性气氛中合成了二维CoSex纳米片，并对其进行了表征.在甲苯-水界面上，Co2+-油胺与NaHSe发生同步还原/沉淀反应，生成水合的Co-O和Co-Se团簇，并在界面张力的驱动下发生强挤压组装。由于侧表面空位的富集，所获得的疏松多孔的Co-Se NS呈现低结晶度。此外，由于CoSex具有较强的吸电子能力，电子可以自发地从CoCo LDH转移到相邻的CoSex纳米晶，从而使CoCo层状双氢氧化物（LDH）中更多的Co原子呈现高氧化态。Co-Se NS的结构、组分和电子构型的这种协同操纵可以增加OER活性位点的密度，提高电导率，并且还提供大的可及表面积和用于离子吸附和传输的可渗透通道。因此，所得的Co-Se NS具有对OER的高催化活性，特别是对于Co-Se-2 NS，在10 mA cm（-2）的电流密度下的1.48 V的低起始电位和仅290 mV的过电位，以及在加速耐久性测试中的良好稳定性。该方法为多组分NS的合成提供了一种可靠有效的途径，并可推广到其他应用领域。
Manipulating the electrical conductivity and morphology of Co-based (hydr) oxides is significant for optimizing energy conversion in the oxygen evolution reaction (OER). Herein, 2D CoSex nanocrystallinedotted porous CoCo layered double hydroxide nanosheets (Co-Se NSs) were designed and synthesized via a modified in situ reduction and interface-directed assembly in an inert atmosphere. During the synchronous reduction/precipitation reaction between Co2+-oleylamine and NaHSe at the toluene-water interface, the hydrated Co-O and Co-Se clusters are generated and sequentially assemble under strong extrusion driven by the interfacial tension. Owing to the enriched vacancies on the lateral surfaces, the obtained loose and porous Co-Se NS presents low crystallinity. Moreover, electrons could spontaneously transfer from the CoCo LDH to the neighboring CoSex nanocrystallites due to the stronger electron-withdrawing capability of metallic CoSex, and thus more Co atoms in the CoCo layered double hydroxide (LDH) present a high oxidation state. This synergistic manipulation in the structure, component, and electron configuration of the Co-Se NS can increase the density of the OER active-sites, improve the electrical conductivity, and also offer a large accessible surface area and permeable channels for ion adsorption and transport. As a result, the resulting Co-Se NSs feature high catalytic activity towards OER, in particular a low onset potential of 1.48 V and an overpotential of only 290 mV at a current density of 10 mA cm(-2) for the Co-Se-2 NS, as well as good stability in an accelerated durability test. The strategy developed here provides a reliable and valid way to synthesize multicomponent NSs, and is able to be extended to other areas of application.