Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Department of Chemical Physics, University of Science and Technology of China , Hefei, Anhui 230026, P. R. China.
Nano Lett. 2017 Dec 13;17(12):7968-7973. doi: 10.1021/acs.nanolett.7b04430. Epub 2017 Nov 30.
Exploring efficient and economical electrocatalysts for hydrogen evolution reaction is of great significance for water splitting on an industrial scale. Tungsten oxide, WO, has been long expected to be a promising non-precious-metal electrocatalyst for hydrogen production. However, the poor intrinsic activity of this material hampers its development. Herein, we design a highly efficient hydrogen evolution electrocatalyst via introducing oxygen vacancies into WO nanosheets. Our first-principles calculations demonstrate that the gap states introduced by O vacancies make WO act as a degenerate semiconductor with high conductivity and desirable hydrogen adsorption free energy. Experimentally, we prepared WO nanosheets rich in oxygen vacancies via a liquid exfoliation, which indeed exhibits the typical character of a degenerate semiconductor. When evaluated by hydrogen evolution, the nanosheets display superior performance with a small overpotential of 38 mV at 10 mA cm and a low Tafel slope of 38 mV dec. This work opens an effective route to develop conductive tungsten oxide as a potential alternative to the state-of-the-art platinum for hydrogen evolution.
探索高效、经济的析氢反应电催化剂对于工业规模的水分解具有重要意义。氧化钨（WO）长期以来一直被认为是一种很有前途的非贵金属析氢电催化剂。然而，该材料较差的本征活性限制了其发展。在此，我们通过在 WO 纳米片中引入氧空位设计了一种高效的析氢电催化剂。我们的第一性原理计算表明，O 空位引入的带隙态使 WO 表现为具有高导电性和理想氢吸附自由能的简并半导体。实验上，我们通过液相剥离制备了富含氧空位的 WO 纳米片，其确实表现出简并半导体的典型特征。在析氢评估中，纳米片表现出优异的性能，在 10 mA cm 时过电势仅为 38 mV，塔菲尔斜率低至 38 mV dec。这项工作为开发导电氧化钨开辟了一条有效途径，使其有望成为析氢反应中替代最先进的铂的潜在选择。
