Water Splitting: Gold Doping in a Layered Co‐Ni Hydroxide System via Galvanic Replacement for Overall Electrochemical Water Splitting (Adv. Funct. Mater. 43/2018)

Abstract

Introducing a low concentration of gold into Co(OH)2 followed by electrodeposition of Ni(OH)2, yields a Co(OH)2‐Au‐Ni(OH)2 composite active in overall water splitting, as Anthony P. O'Mullane and co‐workers report in article number https://doi.org/10.1002/adfm.201804361. Activity for hydrogen evolution or oxygen evolution could be achieved by tuning the gold content between 0.1 and 0.2 at%. This approach may also be applicable to other metal hydroxide/metal nanomaterial composites.

Boosting H2 Generation Coupled with Selective Oxidation of Methanol into Value‐Added Chemical over Cobalt Hydroxide@Hydroxysulfide Nanosheets Electrocatalysts

“…In the case of Co(OH) 2 @HOS/CP electrode, a cell voltage of 1.631 V is needed to achieve the current density of 10 mA cm −2 in 1 m KOH in the absence of methanol. In fact, this potential is lower than those of recently reported Co‐based electrodes for overall water splitting, such as cobalt nitridevanadium oxynitride nanohybrid (1.64 V for 10 mA cm −2 ), cobalt iron hydroxide (1.64 V for 10 mA cm −2 ), 3D Co(OH) 2 @NCNTs@NF (1.72 V for 10 mA cm −2 ), Co(OH) 2 –Au–Ni(OH) 2 (1.75 V for 10 mA cm −2 ), and CoO x (OH) y /C nanocomposites (1.80 V for 10 mA cm −2 ) . Interestingly, the LSV curve of MFO coupled with HER dramatically shifts to more negative potentials, and the cell voltage is reduced to 1.497 V at the current density of 10 mA cm −2 , suggesting much better energy conversion efficiency by replacing OER with MFO.…”

Recovering spent lithium nickel manganese cobalt (NMC) oxide cathodes from Li ion batteries for use as oxygen evolution reaction electrocatalysts

“…5 17,18 while the peak at 793.1 and 798.3 eV belongs to Co 2p 1/2 representing the Co 2+ oxidation state. [19][20][21] For NMC 622 recovered from Cell 3 the XPS spectrum is mostly unchanged apart from a shi to a lower binding energy position from 780.0 eV to 779.6 eV indicating a more reduced Co surface species.…”

Microenvironment‐Engineered Multilayered Electrode Design for Sustainable Seawater Oxidation

“…This interaction results in the formation of an electrophilic center that facilitates enhanced interactions between the highest occupied molecular orbital (HOMO) of OH − ions and the lowest unoccupied molecular orbital (LUMO) of Co, effectively promoting the catalytic reaction by lowering the activation barrier for O–O coupling. [ 53 ] The CO 3 2− group inhibits Cl − ions by facilitating the diffusion of H + ions away from the catalyst interface, preventing Cl − ions from reaching the catalyst surface. [ 37 ] This inhibition not only enhances the catalyst's activity but also improves its corrosion resistance.…”