Wang Zengyao, Chen Jiyi, Song Erhong, Wang Ning, Dong Juncai, Zhang Xiang, Ajayan Pulickel M, Yao Wei, Wang Chenfeng, Liu Jianjun, Shen Jianfeng, Ye Mingxin
Institute of Special Materials and Technology, Fudan University, Shanghai, China.
Department of Chemistry, Fudan University, Shanghai, China.
Nat Commun. 2021 Oct 13;12(1):5960. doi: 10.1038/s41467-021-26256-1.
Non-noble transition metal oxides are abundant in nature. However, they are widely regarded as catalytically inert for hydrogen evolution reaction (HER) due to their scarce active electronic states near the Fermi-level. How to largely improve the HER activity of these kinds of materials remains a great challenge. Herein, as a proof-of-concept, we design a non-solvent strategy to achieve phosphate substitution and the subsequent crystal phase stabilization of metastable β-NiMoO. Phosphate substitution is proved to be imperative for the stabilization and activation of β-NiMoO, which can efficiently generate the active electronic states and promote the intrinsic HER activity. As a result, phosphate substituted β-NiMoO exhibits the optimal hydrogen adsorption free energy (-0.046 eV) and ultralow overpotential of -23 mV at 10 mA cm in 1 M KOH for HER. Especially, it maintains long-term stability for 200 h at the large current density of 1000 mA cm with an overpotential of only -210 mV. This work provides a route for activating transition metal oxides for HER by stabilizing the metastable phase with abundant active electronic states.
非贵金属过渡金属氧化物在自然界中储量丰富。然而，由于它们在费米能级附近缺乏活性电子态，通常被认为对析氢反应（HER）具有催化惰性。如何大幅提高这类材料的HER活性仍然是一个巨大的挑战。在此，作为概念验证，我们设计了一种非溶剂策略来实现磷酸盐取代以及随后亚稳β-NiMoO₄的晶相稳定。事实证明，磷酸盐取代对于β-NiMoO₄的稳定和活化至关重要，它可以有效地产生活性电子态并促进固有的HER活性。结果，磷酸盐取代的β-NiMoO₄表现出最佳的氢吸附自由能（-0.046 eV），并且在1 M KOH中HER的电流密度为10 mA cm⁻²时过电位超低，仅为-23 mV。特别是，它在1000 mA cm⁻²的大电流密度下保持200 h的长期稳定性，过电位仅为-210 mV。这项工作通过稳定具有丰富活性电子态的亚稳相，为激活用于HER的过渡金属氧化物提供了一条途径。
