Electrocatalytic and magnetic properties of ultrathin nanostructured iron-melanin films on Au(111).
We have prepared ultrathin, nanostructured melanin films on Au(111) by means of electrochemical self-assembly. These films were characterized by using Auger electron spectroscopy, X-ray absorption near-edge structure spectroscopy, scanning tunneling microscopy, magnetic force microscopy, and electrochemical techniques. Two types of nanostructures are present in the film: melanin nanoparticles and Fe(3)O(4) nanoparticles. The melanin nanoparticles contain Fe bonded to oxygen-containing phenolic groups in an octahedral configuration similar to that found in Fe(2)O(3). The inorganic-organic composite exhibits magnetic properties and catalyzes the electroreduction of hydrogen peroxide in alkaline and neutral electrolyte solutions. The electrocatalytic activity depends on the Fe-bound melanin and appears to be similar to that found for Fe-porphyrins.
González Orive
Alejandro
A
Departamento de Química Física, Facultad de Química, Universidad de La Laguna, 38071 La Laguna, Tenerife, Spain.
Dip
Patricio
P
Gimeno
Yurima
Y
Díaz
Pilar
P
Carro
Pilar
P
Hernández Creus
Alberto
A
Benítez
Guillermo
G
Schilardi
Patricia L
PL
Andrini
Leandro
L
Requejo
Felix
F
Salvarezza
Roberto C
RC
D002384:Catalysis; D004563:Electrochemistry; D006046:Gold / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D008280:Magnetics; D008543:Melanins / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D046032:Microscopy, Energy-Filtering Transmission Electron; D016252:Microscopy, Scanning Tunneling; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry*; D010084:Oxidation-Reduction; D013057:Spectrum Analysis; D014965:X-Rays
D008543:Melanins; D006046:Gold; D006861:Hydrogen Peroxide; D007501:Iron