We report the synthesis of a new nanocrystal (NC) mesophase through self-assembly of water-soluble NC micelles with soluble silica. The mesophase comprises gold nanocrystals arranged within a silica matrix in a face-centered cubic lattice with cell dimensions that are adjustable through control of the nanocrystal diameter and/or the alkane chain lengths of the primary alkanethiol stabilizing ligands or the surrounding secondary surfactants. Under kinetically controlled silica polymerization conditions, evaporation drives self-assembly of NC micelles into ordered NC/silica thin-film mesophases during spin coating. The intermediate NC micelles are water soluble and of interest for biolabeling. Initial experiments on a metal-insulator-metal capacitor fabricated with an ordered three-dimensional gold nanocrystal/silica array as the "insulator" demonstrated collective Coulomb blockade behavior below 100 kelvin and established the current-voltage scaling relationship for a well-defined three-dimensional array of Coulomb islands.

Coreshell-like Ag2 O/Ag2 CO3 nanoheterostructures with tailored interface are fabricated by a facile, low-cost and one-step phase transformation method. The unique bandgap structure of the Ag2 O/Ag2 CO3 exhibits high separation efficiency of photogenerated electrons and holes, which effectively protects the Ag2 CO3 semiconductor to avoid its photoreduction and gives rise to high activity and stability in degradation of the typical water pollutants.

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