NiCo-BDC derived Co3+ enriched NiCoxOy/NF nanosheets for oxygen evolution reaction.

In recent years, transition metal catalysts due to their low price, excellent conductivity and high activity have been extensively studied in OER. It is worth noting that Co3+ plays a vital role in the process of oxygen evolution catalysis, because Co3+ ions are considered to be active sites. The development of catalysts with high Co3+ content has important application prospects for improving water oxidation efficiency. This paper uses a simple ligand-assisted synthesis method to promote the transformation of two-dimensional layered double hydroxides (LDHs) into two-dimensional metal organic frameworks (MOFs). MOF-OH/NF are quickly and easily prepared by electrooxidation, which exhibit superior OER properties, with a low overpotential of 260 mV and 420 mV for the oxygen evolution reaction (OER) at 100 mA cm−2 and 1000 mA cm−2. Moreover, the MOF-OH/NF has good stability in 1.0 M KOH electrolyte solution. This study provides a new idea for the design and synthesis of novel composite electrocatalysts. • The NiCo x O y /NF is synthesized by a facile electrooxidation method. • High content Co3+ species exist on the surface of the NiCo x O y /NF. • Providing optimized η 100 and η 1000 of 260 mV and 420 mV for OER, respectively. • NiCo x O y /NF exhibits eminent stability and holds steady even during 100 h OER. [ABSTRACT FROM AUTHOR]