Nickel doped cobalt - hollow nanoparticles as an efficient electrocatalyst for hydrogen evolution from neutral water

The development of efficient electrocatalyst based on earth-abundant elements for hydrogen generation under simple conditions is highly desired, but still a serious challenge. Herein, we report a simple synthesis of Ni doped Co hollow nanoparticles (CoNi- HNP) through an easy ultrasonic-assisted chemical reduction method in the presence of non-metal (B and P) and metal (W) as an additive. The addition of low valency non-metals (B and P) and non-3d high valency metals like tungsten (W) improve the near-optimal adsorption energy for hydrogen evolution reaction (HER). The CoNi-HNP requires a 41 mV overpotential to drive a 10 mA cm(-2) current density for HER in 1.0 M potassium phosphate buffer solution (pH = 7). Remarkably, the CoNi-HNP achieves a 400 mA cm(-2) current density at a low overpotential of 417 mV in neutral pH aqueous electrolyte. Moreover, the CoNi-HNP shows better performance during long-term electrolysis as compared to Pt/C. To the best of our knowledge, the CoNi-HNP is the most stable, active and efficient non-noble metal electrocatalyst for hydrogen generation from a neutral solution. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.