Tailored perovskite oxide engineered with multi-dimensional carbon as electrocatalyst to concurrently improve the OER activity and electrochemical stability

Creating highly efficient electrocatalysts for water splitting reactions is crucial for energy conversion purposes. This study focuses on the fabrication of superior non-precious electrocatalysts essential for water splitting applications. Lanthanum cobalt oxide (LaCoO₃)-based multi-dimensional carbon-encapsulated perovskite oxide materials were created, showing remarkable efficiency toward oxygen evolution reaction (OER). We have undertaken a systematic exploration of the impact of different carbon compounds, including acetylene black (AB), multi-walled carbon nanotubes (MWCNT), and reduced graphene oxide (rGO), on the interface modification within LaCoO₃. Our investigation begins with the in situ incorporation of these multi-dimensional carbon materials into LaCoO₃. This process results in well-defined structural and morphological features for LaCoO₃ and its nanocomposites, offering enhanced surface active sites. The LaCoO₃/rGO nanocomposite demonstrates remarkable performance improvements over pristine LaCoO₃, LaCoO₃/AB, and LaCoO₃/MWCNT counterparts. Notably, the LaCoO₃/rGO nanocomposite achieves the lowest onset potential of 1.58 V at a current density of 10 mAcm⁻², coupled with a small Tafel slope of 85 mVdec⁻¹. This enhancement is attributed to the integration of rGO sheets, creating a conductive pathway and introducing electrochemically active sites crucial for catalysis, facilitating efficient charge and mass transport. Additionally, the LaCoO₃/rGO nanocomposite exhibits exceptional long-term stability over 20 h, representing a significant advancement in non-precious electrocatalyst development for clean energy technologies, with promising prospects for future progress.