Mixed-phase cobalt-based nanosheets prepared by rapid thermal annealing for oxygen evolution catalysis

The oxygen evolution reaction (OER), which is based on the geometric structure and interfacial site tailoring of catalysts, is a good technique for producing hydrogen via water electrolysis. Here, we present fluorine and sulfur co-doped cobalt oxide nanosheets (SFO-Co) generated using a quick thermal exfoliation technique as efficient and long-lasting OER electrocatalysts. The SFO-Co catalyst has an ultralow overpotential of 170 mV at 10 mA cm −2 and a large double-layer capacitance ( C dl ) of 94.9 mF cm −2 , thanks to the synergistic effect of numerous anions, high density of active sites, and increased charge transfer capabilities. During a 50-h chronoamperometry test in 1 M KOH solution, the catalyst retains good performance at a steady current of 10 mA cm −2 . This research not only reveals a low-cost, high-efficiency OER electrocatalyst, but it also offers a strategic design for multi-component electrocatalytic material systems that takes electronic reconfiguration into account. Graphical abstract Schematic illustration of two-dimensional sulfur and fluorine co-doped cobalt oxide nanosheets (SFO-Co)