Deep eutectic solvent assisted facile synthesis of low-dimensional hierarchical porous high-entropy oxides

• Published in: Nano research 2022-03, Vol.15 (3), p.2756-2763
• Main Authors: Wei, Jiale, Rong, Kai, Li, Xiaolong, Wang, Yuchen, Qiao, Zhen-An, Fang, Youxing, Dong, Shaojun
• Format: Article
• Language: English
• Subjects: Anodes; Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Carbon sources; Chemistry and Materials Science; Chromium; Cobalt; Condensed Matter Physics; Cooling; Cooling rate; Copper; Electrode materials; Entropy; Functional materials; High temperature; Iron; Lithium; Lithium-ion batteries; Magnesium; Manganese; Materials Science; Nanostructure; Nanotechnology; Nanowires; Nickel; Perovskites; Phase separation; Physicochemical properties; Quenching; Rechargeable batteries; Research Article; Rocks; Salts; Solid phases; Solvents; Synthesis; Urea; Zinc
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-021-3860-7

High-entropy-oxides (HEOs), a new class of solids that contain five or more elemental species, have attracted increasing interests owing to their unique structures and fascinating physicochemical properties. However, it is a huge challenge to construct various nanostructured, especially low-dimensional nanostructured HEOs under the high temperature synthetic conditions. Herein, a facile strategy using glucose-urea deep eutectic solvent (DES) as both a solvent and the carbon source of structure-directed template is proposed for the synthesis of various HEOs with two-dimentional (2D) nanonets and one-dimentional (1D) nanowires, including rock-salt (Co, Cu, Mg, Ni, Zn)O, spinel (Co, Cr, Fe, Mn, Ni) 3 O 4 , and perovskite La(Co, Cr, Fe, Mn, Ni)O 3 . The as-prepared HEOs possessed five or more uniformly dispersed metal elements, large specific surface areas (more than 25 m 2 ·g −1 ), and a pure single-phase structure. In addition, high cooling rate (cooling in air or liq-N 2 -quenching) was indispensable to obtain a single-phase rock-salt (Co, Cu, Mg, Ni, Zn)O because of phase separation caused by copper. By taking advantage of unique features of HEOs, rock-salt (Co, Cu, Mg, Ni, Zn)O can function as a promising candidate for lithium-ion batteries (LIBs) anode material, which achieved excellent cycling stability. This work provides a feasible synthetic strategy for low-dimensional hierarchical HEOs, which creates new opportunities for the stable HEOs being highly active functional materials.