Two Water Stable Copper Metal-Organic Frameworks with Performance in the Electrocatalytic Activity for Water Oxidation

Two novel water stable metal-organic frameworks, [Cu(L)·(4,4′-bipy)·(ClO4)]n (1), [Cu(L)·(phen)·(ClO4)·(H2O)]2 (2), have been constructed by HL=[5-Mercapto-1-methyl] tetrazole acetic acid and Cu (II) salt in the presence of assistant N-containing ligands. MOF 1 and MOF 2 with open CuII sites, resulting the framework 1 and 2 show electrocatalytic activity for water oxidation in alkaline solution. The electrochemical properties of complex for oxygen evolution reaction (OER) were evaluated by linear sweep voltammetry (LSV) and the Tafel slopes. Complex 1 has a higher LSV activity with a lower over potential of 1.54 V and a much higher increase in current density. Meanwhile, the Tafel slope of complex 1 (122.0 mV dec-1) is much lower than complex 2 (243.5 mV dec-1). This phenomenon makes complex 1 a promising porous material for electrocatalytic activity.