Data for：Strong Electronic Interaction in Dual‐Cation‐Incorporated NiSe2 Nanosheets with Lattice Distortion for Highly Efficient Overall Water Splitting

Exploring highly efficient and low‐cost electrocatalysts for electrochemical water splitting is of importance for the conversion of intermediate energy. Herein, the synthesis of dual‐cation (Fe, Co)‐incorporated NiSe2 nanosheets (Fe, Co‐NiSe2) and systematical investigation of their electrocatalytic performance for water splitting as a function of the composition are reported. The dual‐cation incorporation can distort the lattice and induce stronger electronic interaction, leading to increased active site exposure and optimized adsorption energy of reaction intermediates compared to single‐cation‐doped or pure NiSe2. As a result, the obtained Fe0.09Co0.13‐NiSe2 porous nanosheet electrode shows an optimized catalytic activity with a low overpotential of 251 mV for oxygen evolution reaction and 92 mV for hydrogen evolution reaction (both at 10 mA cm−2 in 1 m KOH). When used as bifunctional electrodes for overall water splitting, the current density of 10 mA cm−2 is achieved at a low cell voltage of 1.52 V. This work highlights the importance of dual‐cation doping in enhancing the electrocatalyst performance of transition metal dichalcogenides.

开发用于电化学水分解（electrochemical water splitting）的高效低成本电催化剂，对中间能源转化具有重要意义。本研究报道了双阳离子（Fe、Co）掺杂二硒化镍（NiSe₂）纳米片（Fe, Co-NiSe₂）的合成方法，并系统考察了其电催化析水性能随组分变化的规律。相较于单阳离子掺杂或纯相NiSe₂，双阳离子掺杂可扭曲晶格并诱导更强的电子相互作用，从而提升活性位点暴露量并优化反应中间体的吸附能。最终所得的Fe₀.₀₉Co₀.₁₃-NiSe₂多孔纳米片电极展现出最优催化活性：在1 mol/L KOH电解液中，当电流密度为10 mA cm⁻²时，析氧反应（oxygen evolution reaction, OER）的过电位仅为251 mV，析氢反应（hydrogen evolution reaction, HER）过电位仅为92 mV。当该电极用作全水解双功能电催化剂时，在1.52 V的低槽压下即可达到10 mA cm⁻²的电流密度。本研究凸显了双阳离子掺杂在提升过渡金属二硫族化合物（transition metal dichalcogenides）电催化性能方面的重要价值。