Hollow Platinum Nanoshell Tube Arrays: Fabrication and Characterization

Thin hollow platinum tubes are nanostructures with interesting properties for applications in the fields of catalysis, electrochemistry, biosensors, and fuel cells. In this paper, we describe a facile and fast nanofabrication method to directly prepare hollow platinum nanoshell tube arrays on a wafer through a galvanic replacement reaction (GRR). A silicon wafer containing an array of copper electrodes and a porous silicon oxide layer is used as a template. In the presence of a gold seed layer, platinum particles were deposited homogeneously on the walls of the submicrometer pores of the template structures to form tubular Pt structures by using copper as the reductant. The reaction parameters, the mechanism, and the properties of the platinum micro/nanotubes are discussed. This method can also be applied to other materials such as gold and silver in order to fabricate nanoshell tube arrays or even bimetal structures. The method is CMOS compatible and thus can be applied onto fully processed CMOS circuits in order to create fully integrated nanosensors or actuators.