Construction of Polarized Carbon-Nickel Catalytic Surfaces for Potent, Durable, and Economic Hydrogen Evolution Reactions.
Construction of Polarized Carbon-Nickel Catalytic Surfaces for Potent, Durable, and Economic Hydrogen Evolution Reactions.
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DOI：
10.1021/acsnano.7b08724
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发表时间：
2018-03
期刊：
影响因子：
17.1
通讯作者：
Min Zhou;Qunhong Weng;Z. Popov;Yijun Yang;Liubov Yu. Antipina;P. Sorokin;Xi Wang;Y. Bando;
中科院分区：
文献类型：
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作者：
Min Zhou;Qunhong Weng;Z. Popov;Yijun Yang;Liubov Yu. Antipina;P. Sorokin;Xi Wang;Y. Bando;
电催化析氢反应（HER）在碱性溶液中对水的解离反应动力学迟缓，阻碍了其发展。镍基催化剂作为一种低成本、高效的催化剂，在碱性介质中取代铂基材料具有很大的潜力。这类催化剂的主要挑战是其相对较差的耐久性。在这项工作中，我们构思并构建了一种由碳量子点（CQDs）在Ni3N纳米结构（Ni3N@CQDs）表面衍生的电荷极化碳层，同时具有耐用性和增强的催化活性。Ni3N@CQDs在1 M KOH水溶液中，当电流密度为10 mA cm-2时，过电位为69 mV，低于相同条件下Pt电极的过电位（116 mV）。密度泛函理论（DFT）模拟表明，Ni3N和界面氧极化了CQDs中原相等的C-C键之间的电荷分布。部分带负电荷的C位点通过形成新的C- h键（Volmer步骤）成为关键的水解离步骤的有效催化中心，从而提高HER活性。此外，还发现涂层碳可以保护内部Ni3N免受氧化/羟基化，从而保证其耐久性。这项工作提供了一种实用的基于非贵金属的坚固耐用的HER电催化剂设计。
Electrocatalytic hydrogen evolution reaction (HER) in alkaline solution is hindered by its sluggish kinetics toward water dissociation. Nickel-based catalysts, as low-cost and effective candidates, show great potentials to replace platinum (Pt)-based materials in the alkaline media. The main challenge regarding this type of catalysts is their relatively poor durability. In this work, we conceive and construct a charge-polarized carbon layer derived from carbon quantum dots (CQDs) on Ni3N nanostructure (Ni3N@CQDs) surfaces, which simultaneously exhibit durable and enhanced catalytic activity. The Ni3N@CQDs shows an overpotential of 69 mV at a current density of 10 mA cm-2 in a 1 M KOH aqueous solution, lower than that of Pt electrode (116 mV) at the same conditions. Density functional theory (DFT) simulations reveal that Ni3N and interfacial oxygen polarize charge distributions between originally equal C-C bonds in CQDs. The partially negatively charged C sites become effective catalytic centers for the key water dissociation step via the formation of new C-H bond (Volmer step) and thus boost the HER activity. Furthermore, the coated carbon is also found to protect interior Ni3N from oxidization/hydroxylation and therefore guarantees its durability. This work provides a practical design of robust and durable HER electrocatalysts based on nonprecious metals.