title: Electrocatalysis and electroanalysis of nickel, its oxides, hydroxides and oxyhydroxides toward small molecules.
abstract: The electrocatalysis toward small molecules, especially small organic compounds, is of importance in a variety of areas. Nickel based materials such as nickel, its oxides, hydroxides as well as oxyhydroxides exhibit excellent electrocatalysis performances toward many small molecules, which are widely used for fuel cells, energy storage, organic synthesis, wastewater treatment, and electrochemical sensors for pharmaceutical, medical, food or environmental analysis. Their electrocatalytic mechanisms are proposed from three aspects such as Ni(OH)2/NiOOH mediated electrolysis, direct electrocatalysis of Ni(OH)2 or NiOOH. Under exposure to air or aqueous solution, two distinct layers form on the Ni surface with a Ni hydroxide layer at the air-oxide interface and an oxide layer between the metal substrate and the outer hydroxide layer. The transformation from nickel or its oxides to hydroxides or oxyhydroxides could be further speeded up in the strong alkaline solution under the cyclic scanning at relatively high positive potential. The redox transition between Ni(OH)2 and NiOOH is also contributed to the electrocatalytic oxidation of Ni and its oxides toward small molecules in alkaline media. In addition, nickel based materials or nanomaterials, their preparations and applications are also overviewed here.
authors.affiliation: University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address: yqmiao@ymail.com.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Miao
authors.forename: Lei
authors.initials: L
authors.lastname: Ouyang
authors.forename: Shilin
authors.initials: S
authors.lastname: Zhou
authors.forename: Lina
authors.initials: L
authors.lastname: Xu
authors.forename: Zhuoyuan
authors.initials: Z
authors.lastname: Yang
authors.forename: Mingshu
authors.initials: M
authors.lastname: Xiao
authors.forename: Ruizhuo
authors.initials: R
authors.lastname: Ouyang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D006878:Hydroxides / Q000737:chemistry / Q000302:isolation & purification*; D049329:Nanostructures / Q000737:chemistry; D009532:Nickel / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D054852:Small Molecule Libraries; D012996:Solutions / Q000737:chemistry
chemical_list: D006878:Hydroxides; D054852:Small Molecule Libraries; D012996:Solutions; C037473:nickel hydroxide; D009532:Nickel; C031356:hydroxide ion; C028007:nickel monoxide
keywords: Electroanalysis; Electrocatalysis; Nickel hydroxide; Nickel oxide; Nickel oxyhydroxides