Sol-gel chemistry of transition metal oxides

Organic-inorganic hybrids appear as a creative alternative for obtaining new materials with unusual features. This is related to their diphasic structures, leading to multifunctional materials. The low-temperature processes which are used to synthesize such structures provide a wide versatility in the design of the compounds. The potentiality of the chemistry is to play on the structure of these mixtures and dissociate the various contributions in tailoring both phases and controlling the interfaces. In this paper, a review of some chemistry pathways to hybrid materials is presented. The nature of the bonds between organic and inorganic phases is used to divide them in two major families: class I corresponds to materials with weak interphase bonding, while class II corresponds to materials where both phases are chemically grafted. Applications of these materials in the fields of optics, iono-electronics, mechanics, biology and others are expected. Some applications are reviewed, with respect to the versatility of the synthetic procedure. Most of the properties of these new high-technology materials are dependent on their structural and chemical composition as well as on the dynamical properties inside the blends.

Hybrid organic–inorganic materials: a land of multidisciplinarity

The subject of sol−gel electrochemistry is introduced, starting with a brief account of milestones in its evolution. Then, the types of sol−gel materials that are useful for electrochemistry are presented, followed by a description of recent advances in the various fields of sol−gel electrochemistry. Modified electrodes, solid electrolytes, electrochromic devices, and corrosion protection coatings are described. Emerging fields such as RuO2 supercapacitors and electrochemical synthesis of sol−gel precursors are also addressed.

A. Zarudiansky

Papers

An “all gel” electrochromic device