Efficient hydrogen evolution reaction in alkaline seawater and urea using flower-like Co-NiP@VP/NF electrocatalyst

Abstract

With the depletion of global energy, increasingly severe environmental problems and the pursuit of renewable energy and clean energy, electrocatalytic water splitting has become well-known as an efficient, stable and simple method of hydrogen production. In this paper, M−NiP@VP/NF (M=Co, Mo and Cr) composites were synthesized on nickel foam with low cost, abundant reserves, high conductivity and supportive properties by simple hydrothermal and phosphating methods. Among them, Co-NiP@VP/NF has excellent electrochemical catalytic activity for hydrogen evolution reaction (HER) in seawater electrolyte containing 1.0 M KOH and urea solution containing 1.0 M KOH due to its abundant active sites, dense nanoflower-like structures and accelerated electron transfer rate. The material has a very rich nanoflower-like structure that exposes many contact areas and provides active sites, which also provides the basis for its superior catalytic properties. Notably, the Co-NiP@VP/NF catalyst present overpotential of only 164 mV at 100 mA cm⁻² in 1.0 M KOH + seawater electrolyte solution and has the lowest Tafel slope (65.41 mV dec^-1) for HER. In addition, we also carried out a durability measurement for 15 h, and the result showed a sharp decline at first and then relatively stable. Finally, we also compared the study with other literature, and the catalytic activity of this catalyst is much better than that of most other catalysts. This paper provides a reasonable synthesis method with excellent performance, which provides a possibility for the subsequent extensive application and popularization of seawater.