Wang Gen, Qin Jing, Feng Youyou, Feng Bingxi, Yang Shengjiong, Wang Zheng, Zhao Yongxi, Wei Jing
Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P. R. China.
Shannxi Key Laboratory of Environmental Engineering, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, P. R. China.
ACS Appl Mater Interfaces. 2020 Oct 7;12(40):45155-45164. doi: 10.1021/acsami.0c11899. Epub 2020 Sep 24.
High-entropy oxides (HEOs) have attracted increasing interest owing to their unique structures and fascinating physicochemical properties. Spherical mesoporous HEOs further inherit the advantages of spherical mesoporous materials including high surface area and tunable pore size. However, it is still a huge challenge to construct HEOs with uniform spheres and a mesoporous framework. Herein, a wet-chemistry sol-gel strategy is demonstrated for the synthesis of spherical mesoporous HEOs (e.g., Ni-Co-Cr-Fe-Mn oxide) with high specific surface area (42-143 m/g), large pore size (5.5-8.3 nm), unique spherical morphology (∼55 nm), and spinel structure without any impure crystal phase using polyphenol as a polymerizable ligand. The metal/polyphenol-formaldehyde resin colloidal spheres are first synthesized via a sol-gel process. Because of their abundant catechol groups and strong chelating ability with different metal species, polyphenols can not only accommodate five different metal ions in their networks but also be well polymerized by formaldehyde to form colloidal spheres. After calcination, the metal species aggregate together to form HEOs, while the organic resin is fully decomposed to produce mesopores. Because of the open framework with accessible mesopores, they could be used as a peroxymonosulfate catalyst for degradation of organic pollutants and a nanoplatform for efficient detection of DNA. This work demonstrates a straightforward sol-gel strategy for design and synthesis of spherical mesoporous high-entropy materials, which would promote the exploration of new properties of high-entropy materials and extend their application.
高熵氧化物（HEOs）因其独特的结构和迷人的物理化学性质而受到越来越多的关注。球形介孔高熵氧化物进一步继承了球形介孔材料的优点，包括高比表面积和可调孔径。然而，构建具有均匀球体和介孔骨架的高熵氧化物仍然是一个巨大的挑战。在此，展示了一种湿化学溶胶-凝胶策略，用于合成具有高比表面积（42-143 m²/g）、大孔径（5.5-8.3 nm）、独特球形形态（约55 nm）和尖晶石结构且无任何不纯晶相的球形介孔高熵氧化物（如Ni-Co-Cr-Fe-Mn氧化物），使用多酚作为可聚合配体。首先通过溶胶-凝胶过程合成金属/多酚-甲醛树脂胶体球。由于其丰富的邻苯二酚基团和与不同金属物种的强螯合能力，多酚不仅可以在其网络中容纳五种不同的金属离子，还可以通过甲醛很好地聚合形成胶体球。煅烧后，金属物种聚集在一起形成高熵氧化物，而有机树脂完全分解产生介孔。由于具有可及介孔的开放骨架，它们可用作过一硫酸盐催化剂用于有机污染物的降解和用于DNA高效检测的纳米平台。这项工作展示了一种直接的溶胶-凝胶策略，用于设计和合成球形介孔高熵材料，这将促进对高熵材料新性质的探索并扩展其应用。
