Direct Electrodeposition of Phosphorus-Doped Nickel Superstructures from Choline Chloride–Ethylene Glycol Deep Eutectic Solvent for Enhanced Hydrogen Evolution Catalysis

Abstract

Hydrogen produced by electrochemical water splitting offers a hopeful and renewable solution to address the global energy crisis; however, development of highly efficient hydrogen generation electrocatalysts remains a big challenge. Herein, self-supported P-doped nickel superstructure films (NiP x ) developed on Cu foil were prepared via a facile one-step electrodeposition route from the choline chloride−ethylene glycol (Ethaline)-based deep eutectic solvent (DES). Two depositional patterns including potentiostatic deposition and a consecutive potential cycling approach were compared, and the latter model with a potentiodynamic control was found to be a valid electrochemical protocol to create crack-free NiP x films which were highly active for catalyzing hydrogen evolution reaction (HER) under an alkaline condition. The optimal deposited sample with a Ni/P ratio of 1:0.056 achieved a low overpotential of 105 mV to deliver a current density of 10 mA cm −2 with a small Tafel slope of 44.7 mV dec −1 and excellent catalytic stability for at least 60 h. Detailed experimental investigations coupled with theoretical analyses revealed that the high-performance catalytic activity of the NiP x films originated from the enriched active sites and enhanced electronic conductivity induced by P-doping, which also altered the surface electronic structure of the material and resulted in a lower energy barrier for water dissociation and favorable H adsorption free energy. This study provides a new electrochemical potentiodynamic strategy performed in DES for the fabrication of transition-metal-phosphidebased catalysts for enhancing HER catalysis.

Nickel Phosphide Electrocatalysts for Hydrogen Evolution Reaction

“…A two-electrode water electrolyzer using Ni-P/CF as cathode and anode produces 10 mA/cm 2 at a cell voltage of 1.68 V with high stability. Sun et al prepared P-doped nickel (NiP x ) superstructure films on Cu foil by potentio-static deposition (PSD) and potentio-dynamic (PDD) approach, respectively [135]. By comparing the two deposition methods, it is found that the latter model with a potentio-dynamic control is a valid electrochemical protocol to create crack-free NiP x films.…”

Potential Application of Ionic Liquids for Electrodeposition of the Material Targets for Production of Diagnostic Radioisotopes

“…Other DES-type ILs were examined Gong et al [80] and Sun et al [74]. Gong Later, the same choline-based mixture was applied by Cherigui et al [72] for electrodeposition of Ni nanostructures onto a glassy carbon electrode.…”

“…Other DES-type ILs were examined Gong et al [80] and Sun et al [74]. Gong The coatings were obtained at various potentials (Figure 3).…”

“…The literature devoted to electrochemical characterization of nickel compounds in non-aqueous solutions is rich [ 70 , 71 , 72 , 73 , 74 , 75 ]. Choline chlorine-based ionic liquids are extensively examined in context of their application as a medium for nickel electroplating.…”

Fast Method for Testing the Photocatalytic Performance of Modified Gypsum

“…Photocatalysis is a catalysis process that is used to provide sustainable solutions in several different fields such as biorefinery [1], organocatalysis [2], waste valorization [3], hydrogen evolution [4] and water purification [5].…”