Investigation of the electrocatalytic performance for oxygen evolution reaction of Fe-doped lanthanum nickelate deposited on pyrolytic graphite sheets

Perovskite-type metal oxides have emerged as important materials in renewable energy because the high electrocatalytic performance for oxygen evolution reaction (OER). Hence, we perform a study on the electrocatalytic properties of LaNi1-xFexO3 (x = 0.0, 0.3, 0.6, and 0.9 mol%) for OER, mainly analyzing the influence provoked by the incorporation of Fe3+ in the lattice as well as the use of pyrolytic graphite sheet (PGS) as a potential substrate for electrocatalysis. These perovskites were synthesized by the co-precipitation method. The thin film electrodes were prepared depositing the obtained powders on PGS substrates via drop-casting. Depending on the Fe3+ level, structural changes and morphological modifications were identified for these materials. The highest electrocatalytic activity for OER was detected for LaNi0.4Fe0.6O3. Besides the low charge transfer resistance, LaNi0.4Fe0.6O3 exhibited a lower overpotential (439 mV) and a smaller Tafel slope (52 mV dec−1) than the LaNiO3 (465 mV and 76 mV dec−1).