Cao Dong, Wang Jiayi, Xu Haoxiang, Cheng Daojian
State Key Laboratory of Organic-Inorganic Composites and Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
Small. 2020 Sep;16(37):e2000924. doi: 10.1002/smll.202000924. Epub 2020 Aug 16.
Rational design of low-cost, highly efficient, and stable electrocatalysts for the hydrogen evolution reaction (HER) has attracted wide attention. Herein, 3D RuCu nanocrystals (NCs) are successfully synthesized by a facile wet chemistry method, in which amorphous RuCu nanosheets are directly grown on crystalline Cu nanotubes (NTs). Importantly, the obtained 3D RuCu NCs only need 18 and 73 mV to deliver the current density of 10 mA cm for HER in alkaline and neutral media, respectively. Density functional theory calculations and experiments reveal that the Ru sites on the surface of amorphous nanosheets are the highly active centers for HER. Moreover, this catalyst can expose more surface area for water splitting compared to pure nanosheets because the unique 3D structure can effectively prevent the aggregation of nanosheets. Meanwhile, the interface between amorphous nanosheets and crystalline NTs is essential to boost the HER performance because the amorphous phase with many unsaturated bonds can facilitate adsorption of reactants and crystalline Cu with superior conductivity can promote the transfer of electrons. This work provides a facile method to prepare an original 3D Ru-based electrocatalyst with highly active HER performance in wide pH values.
合理设计用于析氢反应（HER）的低成本、高效且稳定的电催化剂已引起广泛关注。在此，通过一种简便的湿化学方法成功合成了三维RuCu纳米晶体（NCs），其中非晶态RuCu纳米片直接生长在结晶态Cu纳米管（NTs）上。重要的是，所获得的三维RuCu NCs在碱性和中性介质中分别仅需18和73 mV就能实现HER的10 mA cm电流密度。密度泛函理论计算和实验表明，非晶态纳米片表面的Ru位点是HER的高活性中心。此外，与纯纳米片相比，这种催化剂能够暴露出更多用于水分解的表面积，因为独特的三维结构可以有效防止纳米片的聚集。同时，非晶态纳米片与结晶态NTs之间的界面对于提高HER性能至关重要，因为具有许多不饱和键的非晶相能够促进反应物的吸附，而具有优异导电性的结晶态Cu能够促进电子转移。这项工作提供了一种简便的方法来制备一种原始的三维Ru基电催化剂，并在宽pH值范围内具有高活性的HER性能。
