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Molybdenum dioxide and vanadium-doped molybdenum dioxide microcrystals were synthesized by a totally new method involving a redox-active monomer route. The two related dioxides had virtually identical crystal structures and the three precursors used in the process could be subsequently divided in two subgroups of two members each, based on their strong similarities in composition and crystal structure, respectively. Molybdenum trioxide (orthorhombic and hexagonal forms) and the vanadium-doped (10%, molar) molybdenum trioxide (hexagonal form) were used in the redox process with excess pyrrole, and at relatively high temperature (325°C) and long reaction time (12 days), formed a heterogeneous new type of organic-inorganic microcomposite. The new material could be described as a molybdenum dioxide crystal in a polymer box, with the size of the crystallite grain depending on the dimensions of the initial molybdenum trioxide grain and the ratio between the unit cell volumes of the initial and final oxide. The procedure took advantage of the relatively high reduction potentials of the Mo 6+ and V 5+ oxide surface centers towards the oxidative polymerization of pyrrole at intermediate temperatures, and the high catalytic activity of the metal cations in the molybdenum trioxide-based materials towards the total oxidation of the carbon atoms in the organic moiety, at elevated temperatures. This new synthetic route offers good perspectives as precursor composites for nanocrystal engineering in practical applications like heterogeneous catalysis, chemical sensing, nanostructured metallic catalysts, etc.

We demonstrate in this paper that two-dimensional (2-D) layered ceramics, materials that are highly anisotropic in terms of structure and properties can be used to induce the formation of polymer-covered metal nanorods. The procedure took advantage of the intrinsic planar, layered ordering of the metal cations suitable to be reduced and can be further used to engineer one-dimensional (1-D) metal alloy nanostructures by appropriate doping of the initial layered ceramic lattice with suitable cationic species. The procedure involved the formation in an intermediate step of a polymer-layered ceramic nanocomposite, highly porous to the diffusion of the reducing agent. Two structurally similar layered bismuthates, Bi2Sr2CaCu2O8+δand Bi6Sr2CaO12were used as the precursor layered ceramics and the redox-active metal cations were Cu2+and Bi3+.

Two-dimensional layered ceramics, highly anisotropic materials in terms of structure and properties, were used to produce polymer-covered metal nanorods and metal microcrystals. The procedure took advantage of the intrinsic planar, layered ordering of the metal cations suitable to be reduced and could be further used to engineer one-dimensional metal alloy nanostructures by appropriate doping of the initial layered ceramic lattice with suitable cationic species. The procedure involved the formation in an intermediate step of a polymer-intercalated ceramic nanocomposite, highly porous to the diffusion of the polymerizable reducing agent, pyrrole. Two structurally similar layered bismuthates, Bi 2 Sr 2 CaCu 2 O 8+␦ and Bi 6 Sr 2 CaO 12 and a partially Rh-substituted ceramic, Bi 4 Rh 2 Sr 2 CaO 12 were used as the precursor layered ceramics and the reducible metal cations were Cu 2+ , Bi 3+ , and Rh 3+ , respectively. The formation of the polymer-covered metal nanorods and metal microcrystals took place at relatively high temperatures of reaction (325°C) and long reaction times (10-12 days).