Study On Fabrication Of Cu_xO Nanoplate-films By Oxidation-assisted Dealloying Method

Porous nanostructure-films (PNFs) are porous and functional films whichare made of nanoparticles, nanocolumns/nanorods, nanoligaments, nanoplates,nanopores or nanotubes. Due to the high porosity and largesurface-volume-ratio of the films, besides significant small size ornanocurvature effect of low-dimensional nanostructure, PNFs exhibit manyunique physical, chemical and mechanical properties differented fromconventional bulk materials. Therefore, PNFs have wide potentialapplications in catalysts, sensors, fuel cells, solar cells and electrode etc.Currently, methods of preparing PNFs are mainly template, dealloying andbias deposition etc. However, these methods study less in terms of preparationof metal oxide PNFs or have some disadvantages. Therefore, it is necessary todevelop a low cost, simple operation, high efficiency method of preparingmetal oxide PNFs.In this work, a new oxidation-assisted dealloying (OAD) is proposed toprepare metal oxides PNFs on the basis of the conventional dealloying. CuxO,FexO, NixO nanostructure films was obtained by using this method to etchCu-Al, Fe-Al, Ni-Al alloy films. We analyzed the PNFs crystal structure,morphology and optical absorption properties respectively. The main findingsand conclusions are summarized as follows:1. Preparation of metal oxides PNFs has two main oxidation processes byOAD: metal atoms were oxidized by dissolved oxygen in etchant, the topmetal film and the bottom conductive stainless steel substrate automaticallybuild a primary cell, which can oxidize film further;2. We obtained CuO nanoplates film by chemically etching Cu70Al30alloyfilm with10mM NaOH solution;3. Cu70Al30alloy films were annealed in high vacuum,we can obtaineddifferent crystal structure and morphology of CuxO-PNFs by controlling theannealing temperature;4. We can obtained different crystal structure and morphology of CuxO-PNFs by changing Al content of the Cu-Al alloy films and the etchantconcentration;5. Plate like FexO-PNFs were prepared by corroding Fe-Al alloy films, andNixO-PNFs were acquired by eroding Ni-Al alloy films;6. We finally gained CuO, CuxO, FexO, NixO PNFs energy gap byanalyzing UV-visible light optical absorption spectrums of PNFs.