The implementation of nanowires and nanotubes for applications such as thermoelectrics, catalysis, plasmonics, or photoelectrochemical water splitting for hydrogen generation requires both, an excellent control on geometry, crystallinity and composition of the individual nanostructures, as well as its successful assembly into 2-D and 3-D architectures. Fabrication of 3-D nanowire superstructures by vapour–liquid–solid processes has been reported; however, it reveals a limited tunability of the relevant parameters.

This talk will illustrate how the unique combination of electrodeposition and tailored nanochannel templates provides an excellent platform (i) to study and control the nanowire growth, and (ii) to synthesize 3-D nanostructure assemblies and investigate their size-dependent properties.

Membranes with parallel nanochannels are fabricated by swift heavy ion irradiation and subsequent chemical etching. In addition, templates with interconnected tilted nanochannels are obtained by applying ion irradiation at several incident angles in consecutive steps. Nanochannel density and orientation, as well as diameter and geometry, are adjusted by the irradiation and etching conditions, respectively. Subsequent electrodeposition in the channels results in nanowire arrays and highly ordered 3-D nanowire ensembles of various materials. Recent developments achieved on the electrodeposition of metal (Au_1-xAg_x), semiconductor (ZnO and p-Cu₂O) and semimetal (Sb) nanowire arrays and nanowire networks will be presented. Special emphasis will be given to the implementation of the nanowire assemblies in photoelectrochemical and thermoelectric devices, which is possible thanks to the flexibility and control offered by electrodeposition.