Oxygen-Reduction-Triggered Cathodic Electrodeposition of Mn-Based Metal–Organic Framework Nanoflakes as Oxygen Evolution Electrocatalysts

Metal–organic frameworks (MOFs) are promising electrocatalysts for the oxygen evolution reaction (OER) due to their advantages such as high-surface area and porosity. Electrochemical methods are an efficient and facile way to prepare binder-free electrocatalysts on conductive substrates. Herein, Mn-based MOF nanoflakes including Mn-BDC and NiMn-BDC were successfully synthesized on carbon cloth by an oxygen-reduction-triggered cathodic deposition strategy where the O2 acted as an additional probase besides nitrate to promote the deprotonation of ligands, and their OER performance was investigated. The results show that the O2 in the cathodic deposition had a significant effect on the morphology and composition of products. The Mn-BDC and NiMn-BDC prepared with an O2 assistance under an optimum deposition potential and time both displayed better OER performance than the corresponding products without oxygen assistance. The role of O2 was discussed based on the products of the oxygen reduction reaction. This study verified that the oxygen-reduction-triggered cathodic deposition strategy is effective to prepare MOFs with good OER performance.