Optimized Trimetallic Benzotriazole-5-carboxylate MOFs with Coordinately Unsaturated Active site as Efficient Electrocatalyst for Oxygen Evolution Reaction
Exploring efficient and stable oxygen evolution reaction (OER) catalysts with earth-abundant element has been an urgent task in water splitting. Metal-organic frameworks (MOFs), possessing abundant active metal sites and tunable porous crystalline structure, were promised to act as OER catalysts. In this paper, MOFs based on benzotriazole-5-carboxylate (Co3-btca) containing unsaturated coordinated metal centers and 1D channel was selected to act as OER catalyst. To optimize OER performance, isostructural bimetallic and trimetallic frameworks were obtained by doping Fe and/or Ni ions. The optimized Co2.36Fe0.19Ni2.45-btca possesses the lowest overpotential of 292 mV at 10 mA cm2 and a small Tafel slope of 72.6 mV dec-1. The enhanced catalytic performance could be contributed to the synergistic eﬀect between unsaturated coordinated Co, Fe and Ni sites which benefit to nucleophilic attack of OH forming adsorption intermediates.