Modulation of iron-based perovskites for enhanced electrocatalytic oxygen evolution reaction by a multi-method approach

Abstract

Perovskite oxides have been a hot topic of research in the field of water electrolysis due to their tunable construction; however, the poor conductivity and insufficient electrocatalytic activity of extensively studied iron-based perovskites have hindered their widespread availability. While most reported schemes focus on a stand-alone measure to modulate the physicochemical properties of perovskite oxides, herein, we utilize a multi-method approach to improving the parent perovskite SrFeO3-δ (SF). A novel perovskite oxide with a nominal composition of Sr0.9Fe0.6Co0.2Ni0.2O3-δ (S9FCN) is formulated for efficiently catalyzing oxygen evolution reaction (OER) in alkaline electrolytic water, employing the B-site co-doping with the dynamic cations Co, Ni and the A-site Sr deficiency from a highly tunable construction management to enhance the electrocatalytic activity of the targeted perovskite sample. Utilizing this concept, encouragingly, the constructed S9FCN perovskite catalyst exhibits excellent OER catalytic activity with low overpotential of 340 mV at 10 mA cm-2, high mass activity (153.32 A gcatalyst-1) and specific activity (1.91 mA cmBET-2 and 0.11 mA cmECSA-2) under a 400 mV overpotential, along with outstanding electrochemical durability without obvious degradation up to 40 h, which is much superior to that of its parent SF and stoichiometric SFCN counterparts. The improvement of electrochemical performance of iron-based perovskite catalysts by a multi-method approach stands a chance of speeding up the practical application of OER electrocatalysts.