Pang Wei, Shao Bing, Tan Xiao-Qiong, Tang Cong, Zhang Zhong, Huang Jin
State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004, China.
Nanoscale. 2020 Feb 14;12(6):3623-3629. doi: 10.1039/c9nr09742b. Epub 2020 Jan 28.
Single-layer two-dimensional metal-organic framework (MOF) nanosheets combine the characteristic of highly ordered structures of MOFs and unique physical and chemical properties of two-dimensional (2D) materials, which is beneficial for developing high-performance electrocatalysts and studying the structure-property relationships. However, the instability of coordination bonds during exfoliation results in great difficulties in their preparation and characterization. This work takes advantage of the anisotropy of coordination bonds in three-dimensional (3D) pillared-layer MOFs and selectively breaks the interlayer bonding through substitution of the pillared ligands by capping solvent molecules synergized with sonication in a solvent over a relatively short time course (30 min), thus leading to single-layer metal-organic nanosheets, which retain the 2D layered structure of the original crystalline counterpart. The as-synthesized single-layer metal-organic nanosheets are efficient electrocatalysts for the oxygen evolution reaction (OER) with a turnover frequency as high as 0.144 s and 0.294 s at overpotentials of 400 mV and 500 mV in neutral electrolyte media, respectively, which are higher than other heterogeneous catalysts.
单层二维金属有机框架(MOF)纳米片结合了MOF高度有序结构的特点以及二维(2D)材料独特的物理和化学性质,这有利于开发高性能电催化剂并研究结构-性能关系。然而,剥离过程中配位键的不稳定性给它们的制备和表征带来了极大困难。这项工作利用了三维(3D)柱状层MOF中配位键的各向异性,并通过在相对较短的时间过程(30分钟)内在溶剂中用封端溶剂分子取代柱状配体并协同超声处理,选择性地打破层间键合,从而得到单层金属有机纳米片,其保留了原始晶体对应物的二维层状结构。所合成的单层金属有机纳米片是用于析氧反应(OER)的高效电催化剂,在中性电解质介质中,在400 mV和500 mV的过电位下,周转频率分别高达0.144 s和0.294 s,高于其他非均相催化剂。