An Earth-Abundant Tungsten–Nickel Alloy Electrocatalyst for Superior Hydrogen Evolution

Abstract

Hydrogen production with high purity through water splitting has been proved to be a potential energy technology but requires highly efficient, low cost, and robust electrocatalysts. Herein, a tungsten−nickel/nickel foam hybrid is prepared by a facile method and exhibits an outstanding hydrogen evolution reaction activity and remarkable stability in alkaline solution. It only requires an overpotential of 36 mV to afford the current density of 10 mA cm −2 with a small Tafel slope of 43 mV dec −1 . Owing to the excellent electrocatalytic performance arising from the synergistic effect of binary tungsten−nickel interacting through the d-orbital electron transfer, the as-prepared material is the best among tungsten-based HER electrocatalysts. The lower adsorption energy of water molecules and a small Gibbs free energy of hydrogen adsorption (0.17 eV) on tungsten atoms of WNi (111) from DFT calculations reveal the favorable water electrolysis kinetics. Moreover, the simple preparation strategy can be extended to design of other active materials for clean energy technology applications and beyond.

Ultrathin Amorphous Iron–Nickel Boride Nanosheets for Highly Efficient Electrocatalytic Oxygen Production

“…On the contrary,b are Ni foam showedi nsignificanta ctivity in the OER. This enhancement in the performance can be attributed to the hybrid nature of the Fe-6Ni-B catalyst assisted by the highly conductive NF.A dditionally,t he as-prepared Fe-6Ni-B@NF outperforms precious metal-based catalysts upportedo nN Fb yacastingm ethod (RuO 2 /NF) as can be observed in Figure 4b,w here the RuO 2 /NF catalystr equiresa no verpotential of 292 mV to achieve as imilar current density.F urthermore,t he activity of the catalyst is comparable to other nickel-o ri ron-doped nickel-based catalysts supported on ah igh-conductivity material, such as Fe-Ni 3 S 2 /FeNi alloy (282 mV), [19b] NiFeO x /Nif oam (260 mV), [33] Ni-B/ NF (360 mV at 100 mA cm À2 ,c ompared to 275 mV for Fe-6Ni-B@NF at the same currentd ensity), [34] NiFeS/NF (231 mV), [35] W 0.5 Co 0.4 Fe 0.1 /NF (250 and 310 mV at 10 and 100 mA cm À2 ,r espectively), [36] NiFe LDH/NF( LDH = layered double hydroxide) (278 mV) and Ni 0.75 Fe 0.125 V 0.125 -LDHs/NF (231 mV), [37] Ni-Bi NA/ TM (NA = nanosheets array,T M = titaniumm esh)[ 430 mV at 10 mA cm À2 in 0.1 m potassium borate (pH 9.2)], [38] r-NiMoO 4 / NF (249.5 mV), [39] WNi/NF 450 (328 mV at 50 mA cm À2 ), [40] and NiFe-OH-PO 4 /NF (249 mV at 20 mA cm À2 ). [41] For more such comparable materials, see Ta bles S2 and S3 in the Supporting Information.…”

Tailoring of Metal Boride Morphology via Anion for Efficient Water Oxidation

“…[11] The O 1s XPS spectrum in Figure 2f shows no peak at BE of lattice O, instead, the peaks at 531.6 and 533.4 eV ascribed to surface O and adsorbed O, [16] respectively, were observed emphasizing the predominance of oxidized species on the surface. [17] As revealed in Figure 3a and Figure S8, Supporting Information, the Fe3Co7-B/CNT catalyst activity exceeds those of Fe3Co7-B, binary Co-or FeB, and IrO 2 . All potentials reported are referenced to the reversible hydrogen electrode (RHE).…”

Electrodeposited tungsten-rich Ni-W, Co-W and Fe-W cathodes for efficient hydrogen evolution in alkaline medium

“…Among various alternatives, W(Mo)-based alloys with iron group metals, namely Ni, Co and Fe, have attracted considerable research attention during the last decades because of their high electrocatalytic activity [9e11], superior mechanical [12,13], tribological [14e16], anti-corrosion properties [15] and thermal resistance [18,19]. W(Mo) alloy electrodes with iron group metals have been prepared by various methods, such as magnetron sputtering [10,20,21], hydrothermal treatment [22], arc melting [23], mechanical alloying [24e27] and electrodeposition [28e30]. Among them, electrodeposition is considered as rather simple and inexpensive technique which does not require a so-phisticated equipment or large energy expenditure.…”