Heterostructure of Au Nanoparticles-NiAl Layered Double Hydroxide: Electrosynthesis, Characterization, and Electrocatalytic Properties

A heterostructure based on gold nanoparticles (Au-NPs) and NiAI layered double hydroxide (LDH) was prepared by one-step electrosynthesis, directly onto the electrode surface. The resulting material (Au-NPs-NiAl LDH) was characterized by SEM, TEM, UV-vis, XRD, EXAFS, and XANES spectroscopy and by electrochemical techniques. The deposition process of the heterostructure on the Pt electrode was investigated by the electrochemical quartz crystal microbalance (EQCM). The electrocatalytic behavior of Au-NPs-NiAl LDH toward the oxidation of methanol in basic media was compared with those of individual Au-NPs and NiAl LDH, and an enhancement of the catalytic efficiency over a wide methanol concentration range was pointed out.