Single atom tungsten doped ultrathin α-Ni(OH)<sub>2</sub> for enhanced electrocatalytic water oxidation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31089139.
- Also identified by DOI 10.1038/s41467-019-09845-z and PMC identifier 6517434.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Electrocatalytic water oxidation is a rate-determining step in the water splitting reaction. Here, we report one single atom W<sup>6+</sup> doped Ni(OH)<sub>2</sub> nanosheet sample (w-Ni(OH)<sub>2</sub>) 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<sup>2</sup>. Moreover, at high current density of 80 mA/cm<sup>2</sup>, the overpotential value is 267 mV. The corresponding Tafel slope is measured to be 33 mV/dec. The d<sup>0</sup> W<sup>6+</sup> atom with a low spin-state has more outermost vacant orbitals, resulting in more water and OH<sup>-</sup> groups being adsorbed on the exposed W sites of the Ni(OH)<sub>2</sub> nanosheet. Density functional theory (DFT) calculations confirm that the O radical and O-O coupling are both generated at the same site of W<sup>6+</sup>. This work demonstrates that W<sup>6+</sup> doping can promote the electrocatalytic water oxidation activity of Ni(OH)<sub>2</sub> with the highest performance.