Sun Yiqiang, Li Xiuling, Zhang Tao, Xu Kun, Yang Yisong, Chen Guozhu, Li Cuncheng, Xie Yi
School of Chemistry and Chemical Engineering, Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, Anhui, 230601, P. R. China.
School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, P. R. China.
Angew Chem Int Ed Engl. 2021 Sep 20;60(39):21575-21582. doi: 10.1002/anie.202109116. Epub 2021 Aug 21.
The introduction of heteroatoms is one of the most important ways to modulate the intrinsic electronic structure of electrocatalysts to improve their catalytic activity. However, for transition metal chalcogenides with highly symmetric crystal structure (HS-TMC), the introduction of heteroatoms, especially those with large atomic radius, often induces large lattice distortion and vacancy defects, which may lead to structural phase transition of doped materials or structural phase reconstruction during the catalytic reaction. Such unpredictable situations will make it difficult to explore the connection between the intrinsic electronic structure of doped catalysts and catalytic activity. Herein, taking thermodynamically stable cubic CoSe phase as an example, we demonstrate that nitrogen incorporation can effectively regulate the intrinsic electronic structure of HS-TMC with structural phase stability and thus promote its electrocatalytic activity for the hydrogen evolution activity (HER). In contrast, the introduction of phosphorus can lead to structural phase transition from cubic CoSe to orthorhombic phase, and the structural phase of phosphorus-doped CoSe is unstable for HER.
引入杂原子是调节电催化剂本征电子结构以提高其催化活性的最重要方法之一。然而，对于具有高度对称晶体结构的过渡金属硫族化合物（HS-TMC），引入杂原子，尤其是那些具有大原子半径的杂原子，常常会引起较大的晶格畸变和空位缺陷，这可能导致掺杂材料的结构相变或在催化反应过程中的结构相重构。这种不可预测的情况将使得探索掺杂催化剂的本征电子结构与催化活性之间的联系变得困难。在此，以热力学稳定的立方相CoSe为例，我们证明了氮的掺入可以在保持结构相稳定性的情况下有效调节HS-TMC的本征电子结构，从而促进其对析氢反应（HER）的电催化活性。相比之下，磷的引入会导致结构从立方相CoSe转变为正交相，并且磷掺杂的CoSe的结构相对HER不稳定。
