Quasi-ZIF-67 for Boosted Oxygen Evolution Reaction Catalytic Activity via a Low Temperature Calcination

Exposing catalytically active metal sites in metal–organic frameworks with maintained porosity could accelerate electron transfer, leading to improved performances in electrochemical energy storage and conversion. Here, we report a series of quasi-ZIF-67 obtained from low temperature calcination of ZIF-67 for electrocatalytic oxygen evolution reaction (OER) and reveal the nanostructural structure via the spherical aberration-corrected transmission electron microscopy. The quasi-ZIF-67-350 not only possesses a large Brunauer–Emmett–Teller surface area of 2038.2 m2·g–1 but also presents an extremely low charge-transfer resistance of 15.0 Ω. In catalyzing the OER process, quasi-ZIF-67-350 displays a low overpotential of 286 mV at 10 mA cm–2 in the electrolyte of 1.0 M KOH. The acquired quasi-ZIF-67 demonstrates a high catalytic activity in OER, and the controlled calcination strategy undoubtedly paves a way in synthesizing low-cost and efficient electrocatalysts.