Metallized Ni(OH)2·NiO/FeOOH on Ni foam as Highly Effective Water Oxidation Catalyst Prepared by Surface Treatment: Oxidation-Corrosion Equilibrium

The surface treatment method has a great influence on the structure and properties of applied materials for interface catalysis. In this study, we prepare Ni(OH)2·NiO/FeOOH by surface treatment in acid solution using oxidation-corrosion equilibrium (OCE). For comparison, we also treat Ni foam with the same process in alkaline solution. Ni(OH)2·NiO/FeOOH can arrive steady-morphology and metallization by oxidation-corrosion equilibrium and exhibits superior catalytic activity as water oxidation catalyst. Ni(OH)2·NiO/FeOOH(OCE) needs only 232 mV to reach a current density of 10 mA cm-2, while it is 254 mV for a reference IrO2/Ni foam. The mechanism study shows that the small charge transfer resistance (2.04 Ωcm2) is favorable for the rapid interface electron exchange between Ni(OH)2·NiO/FeOOH(OCE) and reactive species in water oxidation. In addition, the results of X-ray photoelectron spectroscopy and series impedance show that the catalyst is metallic property in virtue of exposed mental Ni in Ni(OH)2·NiO/FeOOH(OCE). The volume ratio of hydrogen to oxygen (about 2:1) indicates overall water splitting by the double electrode system. When the volume ratio of hydrogen to oxygen is 2:1, the Faraday efficiency of H2 or O2 is close to 100%. Ni(OH)2·NiO/FeOOH(OCE) exhibits good stability for one month. The research results provide a feasible approach for finding low cost metallized catalysts to replace noble metal as water oxidation catalysts and improving the efficiency of water splitting.

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Metallized Ni(OH)2·NiO/FeOOH on Ni Foam as a Highly Effective Water Oxidation Catalyst Prepared by Surface Treatment: Oxidation–Corrosion Equilibrium

ACS Applied Energy Materials ◽

10.1021/acsaem.1c00384 ◽

2021 ◽

Author(s):

Fei Wang ◽

Xiaoxian Sun ◽

Yi Wang ◽

Huawei Zhou ◽

Jie Yin ◽

...

Keyword(s):

Surface Treatment ◽

Water Oxidation ◽

Oxidation Catalyst ◽

Ni Foam ◽

Highly Effective ◽

Effective Water

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Fe and Cu dual-doped Ni3S4 nanoarray with less low-valence Ni species for boosting water oxidation reaction

Dalton Transactions ◽

10.1039/d1dt03902d ◽

2022 ◽

Author(s):

Xiaoqiang Du ◽

Jiaxin Li ◽

Xiaoshuang Zhang

Keyword(s):

Transition Metal ◽

Water Splitting ◽

Water Oxidation ◽

Oxidation Reaction ◽

High Efficiency ◽

Ni Foam ◽

Metal Materials ◽

Ni Species ◽

Co Doped

Transition metal materials with high efficiency and durable electrocatalytic water splitting activity have aroused widespread concern among scientists. In this work, two cation co-doped Ni3S4 nanoarrays grown on Ni foam...

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Stabilization of a molecular water oxidation catalyst on a dye−sensitized photoanode by a pyridyl anchor

Nature Communications ◽

10.1038/s41467-020-18417-5 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Yong Zhu ◽

Degao Wang ◽

Qing Huang ◽

Jian Du ◽

Licheng Sun ◽

...

Keyword(s):

Water Splitting ◽

Phosphonic Acid ◽

Water Oxidation ◽

Oxidation Catalyst ◽

Molecular Water ◽

Applied Bias ◽

Surface Loading ◽

Dye Sensitized ◽

Monomeric Structure ◽

Molecular Catalysts

Abstract Understanding and controlling the properties of water-splitting assemblies in dye-sensitized photoelectrosynthesis cells is a key to the exploitation of their properties. We demonstrate here that, following surface loading of a [Ru(bpy)3]2+ (bpy = 2,2′-bipyridine) chromophore on nanoparticle electrodes, addition of the molecular catalysts, Ru(bda)(L)2 (bda = 2,2′-bipyridine-6,6′-dicarboxylate) with phosphonate or pyridyl sites for water oxidation, gives surfaces with a 5:1 chromophore to catalyst ratio. Addition of the surface-bound phosphonate derivatives with L = 4-pyridyl phosphonic acid or diethyl 3-(pyridin-4-yloxy)decyl-phosphonic acid, leads to well-defined surfaces but, following oxidation to Ru(III), they undergo facile, on-surface dimerization to give surface-bound, oxo-bridged dimers. The dimers have a diminished reactivity toward water oxidation compared to related monomers in solution. By contrast, immobilization of the Ru-bda catalyst on TiO2 with the 4,4′-dipyridyl anchoring ligand can maintain the monomeric structure of catalyst and gives relatively stable photoanodes with photocurrents that reach to 1.7 mA cm−2 with an optimized, applied bias photon-to-current efficiency of 1.5%.

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TiO2 Nanosheet Arrays with Layered SnS2 and CoOx Nanoparticles for Efficient Photoelectrochemical Water Splitting

Nanoscale Research Letters ◽

10.1186/s11671-019-3168-7 ◽

2019 ◽

Vol 14 (1) ◽

Cited By ~ 4

Author(s):

Zhou Cao ◽

Yanling Yin ◽

Peng Fu ◽

Dong Li ◽

Yulan Zhou ◽

...

Keyword(s):

Water Splitting ◽

Water Oxidation ◽

Environmental Issues ◽

Charge Carriers ◽

Oxidation Catalyst ◽

Hydrogen Fuel ◽

Nanosheet Array ◽

Nanosheet Arrays ◽

Global Energy Supply ◽

Pec Water Splitting

Abstract Converting solar energy into sustainable hydrogen fuel by photoelectrochemical (PEC) water splitting is a promising technology to solve increasingly serious global energy supply and environmental issues. However, the PEC performance based on TiO2 nanomaterials is hindered by the limited sunlight-harvesting ability and its high recombination rate of photogenerated charge carriers. In this work, layered SnS2 absorbers and CoOx nanoparticles decorated two-dimensional (2D) TiO2 nanosheet array photoelectrode have been rationally designed and successfully synthesized, which remarkably enhanced the PEC performance for water splitting. As the result, photoconversion efficiency of TiO2/SnS2/CoOx and TiO2/SnS2 hybrid photoanodes increases by 3.6 and 2.0 times under simulated sunlight illumination, compared with the bare TiO2 nanosheet arrays photoanode. Furthermore, the TiO2/SnS2/CoOx photoanode also presented higher PEC stability owing to CoOx catalyst served as efficient water oxidation catalyst as well as an effective protectant for preventing absorber photocorrosion.

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