Synthesis, structure and electrochemical properties of Co-MOF containing pyridine polycarboxylic acid.

Metal-organic frameworks (MOFs) have been widely used in filed of electrochemistry. Compared with traditional inorganic porous materials, the polyvalent pyridinecarboxylic acid ligands have many advantages which contains more active sites, flexible coordination mode, adjustable structure. Therefore, it becomes good choice for constructing MOFs materials with excellent performance. In this paper, a novel MOF was synthesized by pyridine polycarboxylic acid ligand and CoCl 2 ·6H 2 O using solvothermal method. The physicochemical properties were characterized by FT-IR, powder diffraction and thermogravimetry. Single crystal X-ray diffraction reveal that MOF-1 crystallizes in monoclinic system with P 2 1 / C space group. The central Co2+ ions have a dual core structure with 5 and 6 coordination, respectively. The carboxyl groups show two kinds of coordination modes μ 2 : η1: η1 and μ 2 : η1: η2, and the pyridine N atoms also coordinate to form a three-dimensional network structure. Electrochemical experiments show that MOF-1 has a lower overpotential (339.4 mV) and Tafel slope (65.3 mV·dec−1) with higher ECSA and better OER kinetics. A large number of exposed active sites indicate that the MOF has higher potential as catalyst for oxygen evolution reaction. [Display omitted] • A Co-MOFs based on pyridine polycarboxylic acid ligand were prepared by a simple hydrothermal method. • Electrochemical test show that the MOFs has a lower overpotential and Tafel slope with higher ECSA and better OER kinetics. • MOFs exhibit a porous three-dimensional network structure. [ABSTRACT FROM AUTHOR]