Facile Electrodeposition of Amorphous Nickel/Nickel Sulfide Composite Films for High-Efficiency Hydrogen Evolution Reaction

Abstract

Low-cost preparation of high-efficiency electrocatalysts is challenging the development of electrocatalytic water splitting. Here, amorphous nickel/nickel sulfide composite films with controlled Ni content are prepared directly on nickel foam by adopting the reductant during a facile electrodeposition route, functioning as active hydrogen evolution electrocatalysts. By adopting the reductant during the electrodeposition process, the content of Ni increases in the as-prepared nickel/nickel sulfide composite film, deducing from an energy-dispersive spectrometer. As a result of increased Ni to the optimal ratio, the amorphous nickel/nickel sulfide composite film exhibits remarkable electrocatalytic performance, benefiting possibly the modulated electronic structure, the reduced charge resistance, and the higher effectively electrochemical surface area. In a word, the optimal electrocatalyst presents an excellent catalytic stability and exhibits a small Tafel slope of 79.9 mV•dec −1 and low overpotentials of 43.8 and 134.5 mV to deliver current densities of 10 and 100 mA•cm −2 , respectively. The low-cost preparation of the high-efficiency amorphous nickel/nickel sulfide composite film here suggests that the adopted facile electrodeposition method may provide a feasible route for the fabrication of next-generation high-efficiency electrocatalysts for practical applications.

Electrodeposition: An efficient method to fabricate self‐supported electrodes for electrochemical energy conversion systems

“…Reproduced with permission. [136] Copyright 2021, American Chemical Society electrochemical process enabled the fabrication of a CoNi oxyhydroxide electrode. [118] First, electrodeposition was conducted to prepare ridge-like CoNi on a Ti sheet, and electrochemical oxidation was then employed to form oxyhydroxide (Figure 4A).…”

“…Over the past few decades, many research groups have focused on the development of transition metal compounds such as phosphides, [104,130,131] sulfides, [136][137][138][139][140] and selenides. [141][142][143][144][145] Among them, transition metal phosphides have received much attention because of their high cat-alytic activity for the HER, resulting from the modified electronic structure.…”

“…[137] Similarly, electrodeposition was used to fabricate an amorphous Ni/NiS film by varying the reductant reagent to modulate the Ni content (Figure 4G-I). [136] By controlling the composition, electronic structure, charge transfer resistance, and ECSA of the Ni/NiS film were optimized, which contributed to the high HER performance. Among them, the Ni/NiS film with a Ni/S ratio of 3.09 exhibited an HER overpotential of 43.8 mV at −10 mA cm −2 and a Tafel slope of 79.9 mV dec −1 (Figure 4H,I).…”

VO2 as a Highly Efficient Electrocatalyst for the Oxygen Evolution Reaction

“…Renewable energy sources, such as wind and solar power, are providing an increasing share of the energy supply [ 1 , 2 ]. In particular, electrocatalytic water splitting is considered a promising strategy for the sustainable production of hydrogen from renewable energy sources [ 3 , 4 , 5 , 6 , 7 ]. However, overall water splitting suffers from the sluggish kinetics of anodic oxygen evolution reaction (OER) involving the four-electron oxidative half-reaction [ 8 , 9 ].…”

“…However, overall water splitting suffers from the sluggish kinetics of anodic oxygen evolution reaction (OER) involving the four-electron oxidative half-reaction [ 8 , 9 ]. Therefore, an appropriate catalyst is necessary to accelerate the OER at low overpotentials (η) for enhanced energy conversion efficiencies [ 5 ]. The state-of-the-art OER catalysts are based on precious metals such as IrO 2 and RuO 2 with η close to 300 mV in a 1 M aqueous solution of KOH.…”