A Core-Shell Nanocomposite of Borate Anion-Intercalated NiCoFe-LDH Nanoflakes/Co-BNC Nanorods for Efficient Electrocatalytic Oxygen Evolution

Designing low-cost, high-performance composite catalysts to achieve efficient OER remains a huge challenge. Here, we successfully prepared a core-shell nanocomposite of B, N-doped carbon nanorod-supported borate anion-intercalated ternary metal NiCoFe hydrotalcite nanocomposite on carbon cloth (Co-BNC/CC@NiCoFe-BLDH) through high-temperature boration from the decomposition of Co-MOF and the following electrodeposition of NiCoFe-BLDH. In this efficient electrocatalyst design, the dual enhancement effect of B on catalytic activity is mainly reflected: the doping of B can further improve the electrochemical activity of the material; the borate anion intercalation in layered double hydroxides increases the hydrophilicity, lamellar spacing, and the contact area between the nanocomposite and the electrolyte. Combining these with the orderly distributed and cross-arranged nanosheet network structure that provides abundant pore channels for electrolyte and gas diffusion, this nanocomposite exhibits an excellent electrocatalytic OER performance. Remarkably, the nanocomposite exhibits lower overpotential (209 mV at 200 mA cm^-2) and Tafel slope (83.3 mV dec^-1) in 1.0 M KOH solution. This work will provide ideas for designing NiCoFe-based electrocatalysts with a high-performance OER.