Nickel and Ferrocene as Catalyst Candidates to Promote an Effective Oxygen Evolution Reaction.

The oxygen evolution reaction (OER) is the main bottleneck in water splitting and other key technologies due to its slow kinetics. The development of low-cost, highly active, stable, and more efficient electrocatalysts as an alternative to the commonly expensive and scarce Ir- and Ru-based catalysts used is necessary. The present work reports the preparation of OER catalysts by a straightforward and easy method based on the synergistic effect of Ni/Ferrocene combination that leads to high current densities, lower overpotential, high stability, and low Tafel slope in alkaline conditions. The optimized Ni/Ferrocene catalyst demonstrates exceptional performance, providing a constant potential of ∼1.51 and ∼1.65 V and overpotentials of ∼0.278 and ∼0.420 V for more than 26 and 46 h at current densities of 10 and 100 mA·cm, respectively. It represents an important and significant advance in obtaining electrocatalyst materials for OER anodes without the need for previous and tedious synthetic procedures. Only commercial chemicals with low amounts of metals are employed, thus facilitating that this Ni/ferrocene configuration could be scaled up to real devices.