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.