Hallo, I suggest you to try use AAO as a template and do some electrodeposition process to obtain metal nanoarray. Is a lot of references in this issue, check out our publications for AAO synthesis or scopus for electrodeposition process. AAO is very good for nanofabrication. Good luck :)

Another approach is to use a nanopored polycarbonate template. The pore size varies from 15nm to few micrometer which can be bought commercially. Dissolving the template, unlike AAO is also easy which can be done using dichloromethane. There are lots of literature avaliable on developing nanoarray using template assisted technique. Here is one of my recent publication on developing germanium nanotube using this technique.

A simple and fast technique to grow free-standing germaniumnanotubes and core-shell structures from room temperatureionic liquids, Electrochimica acta, 2014, 121, 154-158

http://www.sciencedirect.com/science/article/pii/S0013468613025243

Abhishek, I can't agree with you: dissolving of AAO template is easy - only need to put the sample to 5wt% H3PO4 solution. More difficult is opening the nanopore - it is the same solution, but we need fully controlled the time because this is the key parameter. Additionaly, one of the advantages of AAO is very good, hexagonally arrangement of nanopores. The pores diameters can by from even 12-15 nm to about 500nm or more, depending on the anodisation acid solution.

Meng, of course, all depends of the materials of nanoarray you want.

Anyway I think that you must use the template assisted method for your nanofabrication, regardless of template kind.

Marta, for me it was working with semiconductors which are very sensitive to air and water. So, the option of using AAO was not possible as it either required dissolving in NaOH solution or as you said H3PO4. However at present we are also starting to use AAO templates as it gives much smoother nanowire unlike the polycarbonate. However we find problems with dissolution due to semiconductors. But if a metal system is electrodeposited, AAO can also be used without any problem.

Abhishek, ok, I understood. Now I started working on semiconductors such as SnO2 and ZnO fabrication by AAO template assisted and I afraid that some problems appears. What do you think, reduction of semiconductors after dissolving of AAO (eg. in H2 at elevated temperature) will be ok for obtained nanostructures? Is the semiconductors will have their properties?

Marta, if you are making ZnO and SnO2, in hydrogen atmosphere it will reduce to their metallic form at elevated temperature. You can electrodeposit the metal and then oxidise it at higher temperature or you can electrochemically oxidise the metal to their oxidised form.

You could also try Reginald Penner's (at University of CA, Irvine) LPNE method.

Thank you very much for all the discussions. I could try the methods as you sugggested. But I do not know whether the etching is an effecient method for the preparationf of metal naorraay on the metal substrate or not. The metals coulde be Ni, Co, Fe, etc.