Transcription methodology for rationally designed morphological complex metal oxides: a versatile strategy for improved electrocatalysis

Abstract

Complex metal oxides such as 3D perovskites, known for their high activity and stability, are traditionally synthesized at high temperatures, leaving little scope for morphological tuning using structure-directing and high temperature-unstable reagents. Present approaches utilize rationally designed hard-template precursors with desired morphologies and adopt transcription of the same to achieve morphologies of complex metal oxides. In the present work, we chose strontium-doped lanthanum manganite (LSMO) as a model system to demonstrate our transcription methodology. The improved electrochemical active sites of LSMO are achieved by tuning unique morphologies of manganese oxide (Mn_xO_y). Diffusion-controlled solid-state route enables transcription of the pre-defined morphologies of Mn_xO_y into the corresponding LSMO. Our best morphological LSMO achieved a ∼4-fold increment in overall electrocatalytic OER performance compared to its solid-state synthesized counterpart. This approach offers a unique way to realize highly efficient OER catalysts of high temperature-synthesized complex metal oxides and can be extended to any general system.