Cobalt phosphide nanoparticles supported within network of N-doped carbon nanotubes as a multifunctional and scalable electrocatalyst for water splitting

In order to realize industrial production of hydrogen through water splitting, it is essential to develop a cost-efficient and scalable approach to synthesize nonprecious electrocatalysts with sufficiently high activity and stability to replace commercial noble-metal-based electrocatalysts. Herein we synthesize cobalt phosphide nanoparticles dispersed within nitrogen-doped carbon nanotube network ([email protected]) via scalable spray drying and thermal treatments. As a multifunctional electrocatalyst, the [email protected] hybrid delivers outstanding activity for HER (in both acidic and alkaline electrolytes), OER and overall water splitting. Remarkably, it shows an ultra-low overpotental of 94 mV to obtain 10 mA cm−2 in HER. It also demonstrates outstanding activity in overall water splitting, requiring only 1.619 V to deliver 10 mA cm−2 with more than 72 h’ long-term stability. The combination of notable performance, multi-functionality and highly scalable spray-drying synthesis method enables this material as a novel and cost-efficient transition metal-based electrocatalysts for overall water splitting.