Multifunctionality Exploration of Ca<sub>2</sub>FeRuO<sub>6</sub>: An Efficient Trifunctional Electrocatalyst toward OER/ORR/HER and Photocatalyst for Water Splitting
Nikhil Kumar, Kumari Naveen, Mukesh Kumar, Tharamani C. Nagaiah, Rahul Sakla, Amrita Ghosh, V. Siruguri, Surasree Sadhukhan, Sudipta Kanungo, Avijit Kumar Paul
Abstract
Durable multifunctional electrocatalysts with zero emission and high catalytic activity are desirable for environmentally benign clean energy technologies such as water-splitting devices, fuel cells, and rechargeable metal–air batteries. Herein, we investigate a new antisite disordered polycrystalline double-perovskite oxide Ca2FeRuO6 (CFR) material for catalytic activity. This makes it a remarkable electrocatalyst with excellent stability in a highly alkaline (1 M KOH) medium for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). The bulk perovskite exhibits significant onset potentials of 0.9 V for ORR and 1.57 V vs the reversible hydrogen electrode (RHE) for OER, creating a superior bifunctional electrocatalyst. The novelty enhances for trifunctionality as it shows a moderate onset potential of −0.19 V vs RHE for HER. Substantially, the present material efficiently accelerates visible-light-driven water splitting for OER at neutral pH with excellent recyclability. The photo-/electroactive perovskite is an exceptional example of a heterogeneous catalyst for multifunctional activity. A plausible mechanistic pathway for the synergistic effects of eg orbit-filling in perovskite oxides for OER, ORR, and HER activities is proposed by density functional theory (DFT) calculations.