Composite materials containing amorphous Cu nanoparticles and nanocrystalline Cu₂O embedded in polyaniline matrices have been prepared by a sonochemical method. These composite materials were obtained from the sonication of copper(II) acetate when aniline or 1% v/v aniline–water was used as solvent. Mechanisms for the formation of these products are proposed and discussed. The physical and thermal properties of the as-prepared composite materials are presented. A band gap of 2.61 eV is estimated from optical measurements for the as-prepared Cu₂O in polyaniline.

To create materials that are composites or hybrids structured on the nanometer scale or the meso-domain, respectively, is one of the major tasks in modern materials science. In this paper, we demonstrate general strategies on how to obtain these nanocomposites founded on the knowledge about ordered mesoporous materials. One strategy involves the formation of the composite by performing a chemical reaction in the pores of a pre-formed ordered mesoporous silica while the other strategy uses compounds that first mold their porous environment in the silica and in a succeeding step react to the final composite. As a model system, here, we present the formation of porous silica–carbon hybrid materials. Besides this more general question, we also tackle the task of finding a suitable application for the obtained nanocomposites. We chose an application as selective solar-absorber materials.