Abstract: Methods of producing nanoporous particles by spray pyrolysis of a precursor composition including a reactive precursor salt and a nonreactive matrix salt are provided, wherein the matrix salt is used as a templating medium. Nanoporous aluminum oxide particles produced by the methods are also provided.

Abstract: In a method and system for controllable electrostatic-directed deposition of nanoparticles from the gas phase on a substrate patterned to have p-n junction(s), a bias electrical field is reversely applied to the p-n junction, so that uni-polarly charged nanoparticles are laterally confined on the substrate by a balance of electrostatic, van der Waals and image forces and are deposited on a respective p-doped or n-doped regions of the p-n junction when the applied electric field reaches a predetermined strength. The novel controllable deposition of nanoparticles employs commonly used substrate architectures for the patterning of an electric field attracting or repelling nanoparticles to the substrates and offers the opportunity to create a variety of sophisticated electric field patterns which may be used to direct particles with greater precision.