Single atom tungsten doped ultrathin ?-Ni(OH)2 for enhanced electrocatalytic water oxidation.
Ontology highlight
ABSTRACT: Electrocatalytic water oxidation is a rate-determining step in the water splitting reaction. Here, we report one single atom W6+ 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/cm2. Moreover, at high current density of 80?mA/cm2, the overpotential value is 267?mV. The corresponding Tafel slope is measured to be 33?mV/dec. The d0 W6+ 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 W6+. This work demonstrates that W6+ doping can promote the electrocatalytic water oxidation activity of Ni(OH)2 with the highest performance.
SUBMITTER: Yan J
PROVIDER: S-EPMC6517434 | biostudies-literature | 2019 May
REPOSITORIES: biostudies-literature
ACCESS DATA