Bamboo-Structured Nitrogen-Doped Carbon Nanotube Coencapsulating Cobalt and Molybdenum Carbide Nanoparticles: An Efficient Bifunctional Electrocatalyst for Overall Water Splitting

Abstract

Developing efficient bifunctional electrocatalysts based on inexpensive and earth-abundant materials for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is essential for large-scale renewable energy storage and conversion processes but remains a major challenge. In this study, a bamboo-structured nitrogen-doped carbon nanotube coencapsulated with metallic cobalt and Mo2C nanoparticles (Co–Mo2C@NCNT) is designed and synthesized by a successive pyrolysis approach and demonstrated to be an efficient and stable bifunctional electrocatalyst for overall water splitting in alkaline medium. Attributing to favorable synergy interaction in composition and structure, the resultant Co–Mo2C@NCNT presents the superior performances toward HER, OER, and even overall water splitting in alkaline medium. To drive a current density of 10 mA cm–2, it needs only an overpotential of ∼186 and ∼377 mV for the electrocatalytic HER and OER, respectively, and a relatively low cell voltage (∼1.628 V) for overall water electrolysis. The present finding would open a new avenue to design and develop electocatalytically active multicomponent architectures for overall water splitting.