Jiang Yi, Wu Xingqiao, Yan Yucong, Luo Sai, Li Xiao, Huang Jingbo, Zhang Hui, Yang Deren
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, P. R. China.
Small. 2019 Mar;15(12):e1805474. doi: 10.1002/smll.201805474. Epub 2019 Feb 20.
Developing an efficient electrocatalyst for the hydrogen evolution reaction (HER) working in both acidic and alkaline solutions is highly desirable, but still remains challenging. Here, Pt Ni ultrathin nanowires (NWs) with tunable compositions (x = 1.42, 3.21, 5.67) are in situ grown on MXenes (Ti C nanosheets), serving as electrocatalysts toward HER. Such Pt Ni@Ti C electrocatalysts exhibit excellent HER performance in both acidic and alkaline solutions, with the Pt Ni@Ti C being the best one. Specifically, Pt Ni@Ti C achieves record-breaking performance in terms of lowest overpotential (18.55 mV) and smallest Tafel slope (13.37 mV dec ) for HER in acidic media to date. Theory calculations and X-ray photoelectron spectroscopy analyses demonstrate that the coupling of MXenes with the NWs not only approaches the Gibbs free energy for hydrogen adsorption close to zero through the electron transfer between them in acidic media, but also provides additional active sites for water dissociation in alkaline solution, both of them being beneficial to the HER performance.
开发一种在酸性和碱性溶液中均能有效工作的析氢反应（HER）电催化剂是非常理想的，但仍然具有挑战性。在此，具有可调组成（x = 1.42、3.21、5.67）的Pt Ni超薄纳米线（NWs）原位生长在MXenes（Ti C纳米片）上，用作HER的电催化剂。这种Pt Ni@Ti C电催化剂在酸性和碱性溶液中均表现出优异的HER性能，其中Pt Ni@Ti C是最佳的。具体而言，就迄今为止在酸性介质中HER的最低过电位（18.55 mV）和最小塔菲尔斜率（13.37 mV dec）而言，Pt Ni@Ti C实现了破纪录的性能。理论计算和X射线光电子能谱分析表明，MXenes与NWs的耦合不仅通过它们在酸性介质中的电子转移使氢吸附的吉布斯自由能接近零，而且为碱性溶液中的水离解提供了额外的活性位点，这两者都有利于HER性能。
