Tailoring the Pore Structure of Porous Ni-Sn Alloys for Boosting Hydrogen Evolution Reaction in Alkali Solution

Abstract

Ni-based alloy is an ideal candidate for its application in the field of hydrogen evolution of water splitting due to its good durability, excellent catalytic properties and low hydrogen evolution overpotential. In this paper, porous Ni-Sn alloy materials were prepared by activation reaction sintering, and the pore structure was tailored by adjusting Sn content. The effects of Sn content and electrolyte temperature on the hydrogen evolution properties of porous Ni-Sn alloy electrodes in 6 mol·L−1 KOH solution were studied by electrochemical measurement methods, such as cyclic voltammetry (CV) curves, electrochemical impedance spectroscopy (ESI) and linear sweep voltammetry, and the mechanism of hydrogen evolution was further discussed. The experimental results reveal that when Sn content is 45 wt%, porous Ni-Sn alloy exhibits the best catalytic performance for hydrogen evolution with a Tafel slope of 164.69 mV·dec−1 and an overpotential of 170 mV. The tested electrode also shows good stability for hydrogen evolution in alkaline solution, and the apparent activation energy calculated at room temperature is 29.645 kJ·mol−1. The catalytic mechanism of hydrogen evolution is as follows: the addition of Sn significantly reduces the dissociation degree of M-H bonds, thereby reducing the overpotential of hydrogen evolution; with the increase of Sn content, the porous Ni-Sn electrode displays a higher electrochemical active surface area (ECSA), which makes porous Ni-Sn alloy exhibit good hydrogen evolution catalytic performance.

Catalytic properties and stability of nickel–tin powder alloys in the process of electrochemical hydrogen evolution from alkali solution

“…The current density j 10 is not reached at potential sweep up to -1.5 V, which indicates the inefficiency of application of such alloys in HER catalysis. Comparison of the catalytic properties in HER reactions of Ni-Sn alloys (with tin content of 20-80 at.%) synthesized in this work and in the works [7,[9][10][11][12] with different structural organization -porous powders obtained by chemical reduction of Sn(II) and Ni(II) or by pressing metallurgical Ni and Sn powders, Ni-Sn alloy coating electrochemically deposited onto a nickel grid with different cell parameters, causes difficulties. The reasons for the difficulties are related to the fact that the authors of these works carried out the electrochemical experiments in KOH solutions with different concentrations 0.1-6.0 mol/dm 3 , at different potential sweep rates, and did not evaluate the stability of catalytic activity electrode during long-term operation.…”

“…Nickel-tin alloys attract special attention of researchers as promising electrode materials (cathodes) for HER in alkaline media. Nickel-tin alloy coatings electrochemically deposited from pyrophosphateglycinate solutions on nickel meshes or compact nickel substrates [7,[9][10][11][12], as well as highly porous materials fabricated by joint pressing of nickel and tin powders were studied as HER catalysts in alkaline media. The catalytic characteristics of porous electrode materials with 65 at.% of nickel are better than those of pure nickel [11].…”

“…Nickel-tin alloy coatings electrochemically deposited from pyrophosphateglycinate solutions on nickel meshes or compact nickel substrates [7,[9][10][11][12], as well as highly porous materials fabricated by joint pressing of nickel and tin powders were studied as HER catalysts in alkaline media. The catalytic characteristics of porous electrode materials with 65 at.% of nickel are better than those of pure nickel [11]. Electrochemically deposited nickel-tin alloys with 60 at.% of Ni also demonstrate high catalytic activity in HER in 1 mol/dm 3 NaOH and 6 mol/dm 3 KOH [7,9,12].…”

Impact of Sintering Temperature Variation on Porous Structure of Mo2TiAlC2 Ceramics

“…This porous material with interconnected pore characteristics, pure phase composition, and low elastic modulus is an ideal candidate for long-term load-bearing hard tissue implants. In our previous study [ 23 ], porous Ni-Sn alloy was prepared by activation reaction method and the HER performance was studied. With the increase in Ni content, the porosity showed a trend of first decreasing and then increasing, and the electrochemical active surface area (ECSA) of the electrode also showed the same changing trend.…”