Pseudocapacitive Ni-Co-Fe Hydroxides/N-Doped Carbon Nanoplates-Based Electrocatalyst for Efficient Oxygen Evolution
Pseudocapacitive Ni-Co-Fe Hydroxides/N-Doped Carbon Nanoplates-Based Electrocatalyst for Efficient Oxygen Evolution
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用于高效析氧的赝电容性镍钴铁氢氧化物/氮掺杂碳纳米板电催化剂
DOI：
10.1002/smll.201801878
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发表时间：
2018
期刊：
影响因子：
13.3
通讯作者：
Yu Han-Qing
中科院分区：
文献类型：
--
作者：
Liu Wu-Jun;Hu Xiao;Li Hong-Chao;Yu Han-Qing
过渡金属氧化物/氢氧化物基电催化剂的析氧反应(OER)催化活性与其在低于OER标准电位时的假电容有关。因此，定义明确的伪电容可能是提高OER的一个很好的补充。本文采用一锅溶剂热法合成了高伪电容Ni-Fe-Co氢氧化物/N掺杂碳纳米板(NiCoFe-NC)基电催化剂。NiCoFe-NC具有很好的伪电容性能，比电容为1849Fg−1，能量密度为31.5WH kg−1。该材料还表现出与基准RuO2催化剂相当的优异的OER催化活性(起始过电位为160 mV，在250 mV时提供10 mA cm−2的电流密度，Tafel斜率为31 mV Dec−1)。X-射线光电子能谱、电化学活性表面积等物理化学和电化学分析表明，优化后的NiCoFe-NC催化剂具有较高的OER催化活性，这主要归因于Ni-Co氢氧化物具有模块化的二维层状结构、Fe(III)物种与Ni、Co金属中心之间的协同作用以及N掺杂碳水凝胶的加入改善了催化剂的亲水性。这项工作为设计和合成高性能金属(氢氧化物)电催化剂提供了一种有用的通用策略。
The oxygen evolution reaction (OER) catalytic activity of a transition metal oxides/hydroxides based electrocatalyst is related to its pseudocapacitance at potentials lower than the OER standard potential. Thus, a well‐defined pseudocapacitance could be a great supplement to boost OER. Herein, a highly pseudocapacitive Ni‐Fe‐Co hydroxides/N‐doped carbon nanoplates (NiCoFe‐NC)‐based electrocatalyst is synthesized using a facile one‐pot solvothermal approach. The NiCoFe‐NC has a great pseudocapacitive performance with 1849 F g−1specific capacitance and 31.5 Wh kg−1energy density. This material also exhibits an excellent OER catalytic activity comparable to the benchmark RuO2catalysts (an initiating overpotential of 160 mV and delivering 10 mA cm−2current density at 250 mV, with a Tafel slope of 31 mV dec−1). The catalytic performance of the optimized NiCoFe‐NC catalyst could keep 24 h. X‐ray photoelectron spectroscopy, electrochemically active surface area, and other physicochemical and electrochemical analyses reveal that its great OER catalytic activity is ascribed to the Ni‐Co hydroxides with modular 2‐Dimensional layered structure, the synergistic interactions among the Fe(III) species and Ni, Co metal centers, and the improved hydrophily endowed by the incorporation of N‐doped carbon hydrogel. This work might provide a useful and general strategy to design and synthesize high‐performance metal (hydr)oxides OER electrocatalysts.