Molybdenum Carbide-Embedded Nitrogen-Doped Porous Carbon Nanosheets as Electrocatalysts for Water Splitting in Alkaline Media
Molybdenum Carbide-Embedded Nitrogen-Doped Porous Carbon Nanosheets as Electrocatalysts for Water Splitting in Alkaline Media
复制标题
碳化钼嵌入氮掺杂多孔碳纳米片作为碱性介质中水分解的电催化剂
DOI：
10.1021/acsnano.7b00365
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发表时间：
2017-04-01
期刊：
影响因子：
17.1
通讯作者：
Feng, Xinliang
中科院分区：
文献类型：
--
作者：
Lu, Chenbao;Tranca, Diana;Feng, Xinliang
碳化钼（Mo 2C）基催化剂是酸性介质中最有前途的析氢电催化剂之一，但在碱性介质中的研究较少，这可能是由于活性中心有限、导电性差和水解离能垒高。在这项工作中，Mo 2C嵌入氮掺杂的多孔碳纳米片（Mo 2C @2D-NPCs）成功地实现了一个方便的界面策略的帮助下。作为碱性溶液中的HER电催化剂，Mo 2C @2D-NPC表现出极低的起始电位（近似于0 mV）和在近似于45 mV的过电位下的10 mA cm（-2）的电流密度，这远低于大多数报道的HER电催化剂的值并且与贵金属催化剂Pt相当。此外，Mo 2C @2D-NPC的Tafel斜率和交换电流密度分别为46 mV decade（-1）和1.14 X 10（-3）A cm（-2），在碱性介质中优于现有技术的基于金属碳化物的电催化剂。这种优异的HER活性归因于丰富的Mo 2C/NPC异质结构和氮掺杂的协同贡献、石墨烯的优异导电性以及异质结构中丰富的活性位点。
Molybdenum carbide (Mo2C) based catalysts were found to be one of the most promising electrocatalysts for hydrogen evolution reaction (HER) in acid media in comparison with Pt-based catalysts but were seldom investigated in alkaline media, probably due to the limited active sites, poor conductivity, and high energy barrier for water dissociation. In this work, Mo2C-embedded nitrogen doped porous carbon nanosheets (Mo2C@2D-NPCs) were successfully achieved with the help of a convenient interfacial strategy. As a HER electrocatalyst in alkaline solution, Mo2C@2D-NPC exhibited an extremely low onset potential of similar to 0 mV and a current density of 10 mA cm(-2) at an overpotential of similar to 45 mV, which is much lower than the values of most reported HER electrocatalysts and comparable to the noble metal catalyst Pt. In addition, the Tafel slope and the exchange current density of Mo2C@2D-NPC were 46 mV decade(-1) and 1.14 X 10(-3) A cm(-2), respectively, outperforming the state-of-the-art metal-carbide-based electrocatalysts in alkaline media. Such excellent HER activity was attributed to the rich Mo2C/NPC heterostructures and synergistic contribution of nitrogen doping, outstanding conductivity of graphene, and abundant active sites at the heterostructures.