M3O4(M=FeCoCrMnMg)高熵氧化物粉体的简易制备及超电容性能研究

高熵氧化物以其独特的结构和潜在的应用前景引起了越来越多的关注。本工作采用简单易行的固相反应法制备了M₃O₄(M=FeCoCrMnMg)高熵氧化物粉体, 采用不同手段对粉体进行表征, 并采用涂覆法制备了 M₃O₄/泡沫镍(M₃O₄/NF)复合电极, 研究其超电容性能。结果表明, 随着煅烧温度升高, Fe₂O₃(H)/Co₃O₄(S)/Cr₂O₃(E)和Mn₂O₃(B)相继固溶进入尖晶石主晶相晶格; 在900 ℃煅烧2 h所得M₃O₄粉体的平均粒径为0.69 μm, 具有单一尖晶石结构(面心立方, Fd-3m, a=0.8376 nm), 且Fe、Co、Cr、Mn和Mg五种元素在晶粒内均匀分布, 呈典型的高熵氧化物特征。此外, M₃O₄/NF复合电极在1 mol/L KOH的电解液中, 当电流密度为1 A·g^-1时, 其质量比电容达到193.7 F·g^-1, 可见M₃O₄高熵氧化物在超级电容器电极材料领域具有良好的应用前景。

Facile Synthesis and Supercapacitor Performance of M3O4(M=FeCoCrMnMg)High-entropy Oxide Powders

High-entropy oxides have attracted more and more attention due to their unique structures and potential applications. In this work, M₃O₄(M=FeCoCrMnMg) high entropy oxide powders were synthesized by a facile solid-state reaction method. The powders were characterized by different methods. Furthermore, M₃O₄/Ni foam (M₃O₄/NF) electrode was prepared by a coating method, followed by investigation of its supercapacitor performance. The results showed that, with the increase of calcining temperature, Fe₂O₃(H)/Co₃O₄(S)/Cr₂O₃(E) and Mn₂O₃(B) dissolved successively in the crystal lattice of spinel structure. After M₃O₄ powders being calcined at 900 ℃ for 2 h, single spinel structure (FCC, Fd-3m, a=0.8376 nm) was obtained with uniform distribution of Fe, Co, Cr, Mn, and Mg elements, the typical characteristic of high entropy oxide. In addition, the mass specific capacitance of M₃O₄/NF composite electrode is 193.7 F·g^-1, with 1 mol/L KOH as electrolyte and 1 A·g^-1 as current density, which indicated that the M₃O₄ high entropy oxide can be considered as a promising candidate for the electrode material in the field of supercapacitor applications.