High-density arrays of platinum nanostructures and their hierarchical patterns

A strategy to achieve hexagonal mesoporous silica templates with vertical channels is described. Each nanowire is almost single crystalline and individually grown. The use of mesoporous silica allows feature sizes as small as 9 nm. The kinetic control of the electrodeposition determines the morphology and crystallinity of Pt grown in mesoporous silica. Most of the nanowires lie horizontally because of the mechanical force exerted by the blade and they are loosely interconnected to neighbouring ones. The successful selective deposition of patterned Pt nanowire arrays by microcontact printing of an octadecyltrichlorosilane (OTS) on mesoporous silica film surfaces showed that the template structure is isotropic and so its replica also is expected to be 3D because of the nature of the electrochemical deposition process, which involves the diffusion of ions PtCl₄2- ions to the tips of growing nanowires..