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Herein, three new coordination polymers (CPs), namely {Ni (4,4′-abpt)(2,5-fdca)H2O]n (1), [Co(4,4′-abpt)(2,5-fdca)H2O]n (2) and [Co(4,4′-abpt)(1,3-abc)]n (3) {4,4′-abpt = 3,5-di-4-pyridinyl-4H-1,2,4-triazol-4-amine, 2,5-fdca2− (the fully deprotonated forms of 2,5-furandicarboxylic acid), 1,3-abc2− (the fully deprotonated forms of 1,3-adamantanedicarboxylic acid)} were synthesized under solvothermal conditions and were characterized by elemental analysis, thermogravimetric analysis, powder X-ray diffraction, and single crystal X-ray diffraction (1 and 3) techniques. Structural analyses revealed that 1 is a two-dimensional structure with quadrilateral holes, while 3 is a two-dimensional rhombus network configuration with a binuclear metal center. Three as-prepared compounds exhibited efficient photocatalytic performance for the degradation of organic dyes of crystal violet (CV), methylene blue (MB), and rhodamine B (Rh-B) under UV irradiation, among which, 1 exhibited the best photocatalytic activity with a percentage degradation of more than 96% for the three dyes in 30 min. In addition, in the free radical capture experiment involving 3, it was found that both, the hydroxyl radical OH˙ and superoxide radical (˙O2−) were involved in the degradation process of dyes, among which, the OH˙ radical is the main species to trigger the photocatalytic degradation experiment. Finally, the electrocatalytic performance of the catalysts was investigated in 1 M alkaline KOH solution, and the results showed that all three catalysts had certain electrocatalytic performance, and the catalytic performance of 1 was slightly better than that of 2 and 3. It exhibited a low overpotential of 367 mV at a current density of mA cm−2. [ABSTRACT FROM AUTHOR]

A novel two-dimensional Co-MOF material {[Co(dptz)2(oba)2]·(DMF)2}n is prepared using mixed organic ligands, which exhibits both OER (oxygen evolution reaction) and HER (hydrogen evolution reaction) catalytic performance. The integration of an Fe dopant and amorphous interface into Co-MOF to improving the electrocatalytic performance of pristine MOFs (metal–organic frameworks) is demonstrated and the origin of the remarkable electrocatalytic performance of the catalyst is elucidated. The comprehensive characterization data of Fe@Co-MOFs illustrate that there is a crystallinity transition during the doping of Co-MOF, which increases the electron transfer rate of the material and ensures increased exposure of the ligand unsaturated active site on the surface, and modulates the electronic structure of the Co center in a synergistic manner. As a result, the optimized catalytic Fe@Co-MOF-3 with an amorphous structure exhibits outstanding electrocatalytic performance for the OER, with only 248 mV at a current density of 50 mA cm−2 and excellent stability after 11 h of testing in alkaline solution. Not only that, the HER was achieved with a low overpotential of 150 mV at 10 mA cm−2. The present work indicates that the as-synthesized Co-MOF and Fe@Co-MOFs offer prospects in developing electrocatalysts for water splitting. [ABSTRACT FROM AUTHOR]

A novel two-dimensional Co-MOF material {[Co(dptz) 2 (oba) 2 ]·(DMF) 2 } n is prepared using mixed organic ligands, which exhibits both OER (oxygen evolution reaction) and HER (hydrogen evolution reaction) catalytic performance. The integration of an Fe dopant and amorphous interface into Co-MOF to improving the electrocatalytic performance of pristine MOFs (metal-organic frameworks) is demonstrated and the origin of the remarkable electrocatalytic performance of the catalyst is elucidated. The comprehensive characterization data of Fe@Co-MOFs illustrate that there is a crystallinity transition during the doping of Co-MOF, which increases the electron transfer rate of the material and ensures increased exposure of the ligand unsaturated active site on the surface, and modulates the electronic structure of the Co center in a synergistic manner. As a result, the optimized catalytic Fe@Co-MOF-3 with an amorphous structure exhibits outstanding electrocatalytic performance for the OER, with only 248 mV at a current density of 50 mA cm -2 and excellent stability after 11 h of testing in alkaline solution. Not only that, the HER was achieved with a low overpotential of 150 mV at 10 mA cm -2 . The present work indicates that the as-synthesized Co-MOF and Fe@Co-MOFs offer prospects in developing electrocatalysts for water splitting.