Abstract:
In recent years, the development of electrochemical water oxidation requires an efficacious heterogeneous electrocatalyst to improve the high catalytic activity. Herein, newly designed three transition metal-based phosphonate materials i.e., cobalt phosphonate (CoEDA), nickel phosphonate (NiEDA), and nickel-cobalt phosphonate (NiCoEDA), were synthesized using etidronic acid (1-Hydroxyethane 1,1-diphosphonic acid) as the organophosphorus source under hydrothermal reaction condition at pH 6.5. Among these materials, CoEDA exhibits a high surface area with a proper microporous channel, one of the key parameters for showing excellent electrocatalytic activity towards oxygen evolution reaction (OER) with a lower overpotential (318 mV) and Tafel slope (70.1 mV dec(-1)). The superior catalytic activity towards OER can be correlated with the presence of the organic-inorganic hybrid material containing Co-O-P bond and the formation of highly electroactive cobalt oxyhydroxide (CoOOH) species onto the pore wall of the microporous channel. Besides, as-synthesized CoEDA catalyst displays outstanding catalytic stability for 25 h with a change in current density of only 6%.