No abstract

No abstract

The high intermediate (H*, OH*) energy barriers and slow mass/charge transfer increase the overpotential of alkaline water electrolysis at large‐current‐density. Engineering the electronic structure with the morphology of the catalyst to reduce energy barriers and improve mass/charge transportation is effective but remains challenging. Herein, a Ce‐doped CoP nanosheet is hybrid with Ni3P@NF (Ni foam) support to enhance mass/charge transfer, tune energy barriers, and improve water‐splitting kinetics through a synergistic activation. The engineered Ce0.2‐CoP/Ni3P@NF cathode exhibits an ultralow overpotential (η500, η1000) of −185, and −225 mV at −500 and −1000 mA cm−2 in 1.0 m KOH, along with an excellent pH‐universality. Impressively, an electrolyzer using the Ce0.2‐CoP/Ni3P@NF cathode can afford 500 mA cm−2 at a cell voltage of only 1.775 V and maintain stable electrolysis for 200 h in 25 wt% KOH (50 °C). Characterization and density functional theory calculation further reveal the Ce‐doping and CoP/Ni3P hybrid interaction synergistically downshift d‐band centers (εd = −2.0 eV) of Ce0.2‐CoP/Ni3P to the Fermi level, thereby activate local electronic structure for accelerating H2O dissociation and optimizing Gibbs free energy of hydrogen adsorption (∆GH*).

No abstract

Discovering the multimetallic electrocatalyts with more active sites, superstability, and higher active areas toward oxygen evolution reaction (OER) is highly urgent for energy reserves. Herein, this work puts forward a novel ternary NiCoRu-layered double hydroxide (NiCoRu-LDH) synthesized via a facile one-step chloride (Cl − ) corrosion for Ni foam (NF) in the situ process as an excellent electrocatalyst toward OER. The introduction of Ru cations prominently altered the electronic properties of NiCo-LDH, exposing more surface active sites, and optimizing the intermediates of adsorption oxygen (OOH*) for water oxidation. As expected, the obtained trimetallic NiCoRu-LDH/NF electrode revealed a fairly low overpotential toward OER (270 mV at 100 mA•cm −2 ) with a Tafel slope of 40 mV•dec −1 and prolonged stability (55 h at 100 mA•cm −2 ) in alkaline solution, outperforming most of the hydroxide-based electrocatalysts currently reported. Our work demonstrates an effective approach to designing the highly efficient multimetallic electrodes toward OER.