Co, N co-doped Ni2P on Ni foam as a bifunctional electrocatalyst for oxygen evolution reaction and urea oxidation reaction

초록

Water electrolysis is considered as promising technology for high-purity hydrogen production without emission of environmental pollutants. However, the sluggish kinetics of anodic oxidation reaction (OER) induce the low coulombic efficiency of overall water electrolysis. To address this issue, the OER could be replaced by thermodynamically favorable urea oxidation reaction (UOR). Furthermore, abundant urea species in wastewater can be effectively purified via the electrocatalytic UOR process. To date, the expensive noble metal-based materials have been employed as state-of-the-art electrocatalyst for water oxidation. Therefore, many researchers have devoted to developing UOR electrocatalysts with low cost and high electrocatalytic activity to conduct hydrogen production and wastewater purification, simultaneously. In this study, we prepared Co, N dual-doped Ni2P (Co-Ni2P-N) directly grown on Ni foam (NF) as a bifunctional electrocatalyst for OER and UOR. The as-synthesized Co-Ni2P- N/NF electrocatalyst exhibited the excellent electrocatalytic performance toward OER with the overpotential of 329 mV to deliver 100 mA cm?2 and the remarkable stability during 100 h. For UOR, the low potential of 1.39 V vs. RHE was required at 100 mA cm?2, and electrocatalytic performance was retained over 100 h. The enhanced electrocatalytic performance of Co-Ni2P- N/NF is mainly attributed to the moderately adjusted surface electronic structure via simultaneous introduction of Co, N dual dopants into Ni2P structure. This research would provide the new insight into the development of efficient electrocatalyst for energy conversion and storage system and wastewater treatment.