Single atom tungsten doped ultrathin α-Ni(OH)2 for enhanced electrocatalytic water oxidation

Abstract

Electrocatalytic water oxidation is a rate-determining step in the water splitting reaction. Here, we report one single atom W 6+ doped Ni(OH) 2 nanosheet sample (w-Ni(OH) 2 ) with an outstanding oxygen evolution reaction (OER) performance that is, in a 1 M KOH medium, an overpotential of 237 mV is obtained reaching a current density of 10 mA/cm 2 . Moreover, at high current density of 80 mA/cm 2 , the overpotential value is 267 mV. The corresponding Tafel slope is measured to be 33 mV/dec. The d 0 W 6+ atom with a low spin-state has more outermost vacant orbitals, resulting in more water and OH − groups being adsorbed on the exposed W sites of the Ni(OH) 2 nanosheet. Density functional theory (DFT) calculations confirm that the O radical and O-O coupling are both generated at the same site of W 6+ . This work demonstrates that W 6+ doping can promote the electrocatalytic water oxidation activity of Ni(OH) 2 with the highest performance.

Approaching the activity limit of CoSe2 for oxygen evolution via Fe doping and Co vacancy

“…lies at the heart of efficient catalyst design, as it effectively tunes the binding energies of reaction intermediates 3,4 . Most previous studies, however, utilize only one technique to manipulate the electronic structure, and thus the catalytic performance is barely satisfactory 5,6 . For instance, CoSe 2 has moderate catalytic activity toward oxygen evolution reaction (OER), and the doping of Fe has been demonstrated to be an effective approach to improving the performance 7,8 .…”

Atomic Thickness Catalysts: Synthesis and Applications

“…Wet-chemical synthesis Noble-metals (alloys), Rh, [53] Pd, [24] Rh@Pt nL , [120] Pd-Pt-Ag, [22] PdMo, [18] PtPdNi, [59] RuCu, [56] AL-Pt@Pt 3 Ga, [21] PtGa [25] ORR, [18,25,59] OER, [9] CRR, [24] MOR, [21,53] EOR [22,120] HER [92] Metallic TMDs, 1T′-MoS 2 [92] LDHs, NiFe-LDHs [9] Hydro/solvothermal synthesis Metal (alloys) Rh, [46] RhPd-H, [3] NiCo, [64] NiMo [65] HER, [3,48,51,65] OER, [8,51] CRR [11] TMOs, MnO 2 , [51] TiO 2 , [48] Ni(OH) 2 [8] Other ATCs: Bi 3 O 4 Br [11] Template-assisted synthesis Various kinds of ATCs, Bi, [91] Fe, [69] Au, [70] PdCo, [80] Sn confined in graphene, [31] 1T-MoS 2 /NiS 2 , [20] hexagonal-MoO 3 [73] ORR, [80] CRR, [91] HER [20] Electrochemistry-assisted synthesis Monolayer metal layer: Pt AL @...…”

“…[1] The commercial IrO 2 / RuO 2 catalysts for oxygen evolution reaction (OER) have some disadvantages in high-cost and longterm-instability. [8][9][10] All in all, as for the CO 2 reduction reaction, current catalysts are largely limited to the low catalytic activity and poor production selectivity, which greatly limit the possible practical applications. [11] Recently, intensive attentions have been paid to the ultrathin nanostructures due to their unique surface-related properties, for instance, high electron mobility, [12,13] quantum Hall effect, [14] and unprecedented optoelectronics.…”

“…Hydrothermal method is a promising applicable approach to synthesize various transition metal oxides-based ATCs, such as MnO 2 , [51] TiO 2 , [63] Ni(OH) 2. [8] For example, Zhang's group has successfully prepared bilayer δ-MnO 2 NSs with the thickness of 1.4 nm in situ grown on nickel foam using this strategy. [51] However, it is still challenging to prepare non-noble metals (or alloys) using one-step hydrothermal method owing to the different crystal structures and reduction potentials of metal precursors as well as the prioritized close packing of metal atoms.…”

Editorial: Key Electrochemical Energy Reactions Catalyzed by Nanomaterials

“…Among them, the noble metal-based catalysts exhibit attractive catalytic performance, but their rare nature hinders large-scale application. In recent years, a large variety of non-noble-metal or non-metal-based alternative catalysts using abundant and low-cost 3d metals (e.g., Fe, Co) has been studied with increasing activity and stability (Yan et al, 2019).…”