Facile synthesis of Co-CoOx/N-doped carbon nanotubes hybrids as efficient and bifunctional catalysts for hydrogen and oxygen evolution

Developing low-cost, efficient, and bifunctional electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is an attractive yet challenging task. Herein, we report a novel, simple and one-pot method to fabricate ultrafinely dispersed Co-CoO x nanoparticles encapsulated in a nitrogen doped carbon nanotubes (denoted as Co-CoO x /CN) via an efficient thermal condensation of d -glucosamine hydrochloride, melamine and Co(NO 3 ) 2 ·H 2 O. A well-designed Co-CoO x based hybrid that possesses high activity and excellent durability for the OER and HER in alkaline solution has been fabricated. The catalyst displays good stability for 30,000 s and small Tafel slope of 82 mV per decade for OER and 110 mV per decade for HER. Detailed electrochemical and physical studies indicate that the high OER and HER activity of the hybrid catalyst arises from the strong interaction between Co-based NPs and N-doped carbon nanotubes, and especially the synergistic effect of Co and cobalt oxide.