Pd-doped Urchin-like MnO2-carbon Sphere Three-dimensional (3D) Material for Oxygen Evolution Reaction.

Carbon spheres (CSs) with an average diameter of around 500 ∼ 700 nm are prepared by a extended Stöber method. Urchin-like MnO 2 nanorods were deposited on the carbon spheres by hydrothermal method and the thickness of α-MnO 2 shell is about 700 ∼ 800 nm. Pd particles with a diameter of around 8 ∼ 15 nm are dispersed on the surface of vertically aligned α-MnO 2 rods which have a diameter of 40 ∼ 50 nm. Three-dimensional (3D) Pd-MnO 2 /CS shows better activity and stability than Pd/CS and MnO 2 /CS for anodic oxygen evolution reaction (OER) in water electrolysis, which shows that Pd-doped urchin-like CS-MnO 2 core-shell structure material would be a superiority catalyst for the OER. The onset potential shifts negatively and current density improves on the Pd-MnO 2 /CS for the OER, showing a synergistic effect between Pd and MnO 2 . [ABSTRACT FROM AUTHOR]