Tuning the Morphology of Lanthanum Cobaltite Using the Surfactant-Assisted Hydrothermal Approach for Enhancing Oxygen Evolution Catalysis

Abstract

The high consumption rate of fossil fuels to meet the global energy demands attracts the progress of innovative energy storage and conversion systems. Among them, water electrolysis shows major concern because of its great potential to produce clean hydrogen energy. The dawdling dynamics of the oxygen evolution reaction (OER) that occurs on the anode results in the low energy efficiency of the process. Perovskite oxide with transition metal on the B site possesses a high intrinsic as well as extrinsic activity toward OER. However, the low specific surface area restricts their catalytic activity. Here, we report on the synthesis of lanthanum cobaltite (LaCoO3) nanoparticles and bundles of nanorods using glycine and PVP surfactants, respectively, via the hydrothermal method. Structural characterizations confirmed the pure phase synthesis of LaCoO3 perovskite nanomaterials and further their electrocatalytic performance is investigated in an alkaline medium (1 M KOH). The results show that randomly oriented bundles of nanorods (average length 515 nm, average diameter 65 nm) exhibit smaller overpotential (? = 420 mV) at j = 10 mA cm?2 and the Tafel slope (99 mV dec?1) compared with nanoparticles (? = 450 mV and Tafel slope ~ 110 mV dec?1). The dramatically improved OER activity and larger electrochemical surface area (ECSA) of nanorods as compared to nanoparticles are because of the interconnected porous architecture of nanorods. Our work not only highlights the surfactant-assisted hydrothermal approach to synthesize the nanorods but also introduces the effect of a change in morphology on electrochemical activity. � 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.