Non-Conventional Sol-Gel Routes to Nanosized Metal Oxides for Gas Sensing: From Materials to Applications

Nanosized metal oxides are attractive for a range of applications due to their excellent chemical and thermal stability, high porosity and large surface area. They exhibit also peculiar electrical and sensing properties. Therefore, nowadays, great efforts in fundamental and applied research is dedicated to the optimization of new procedures able to synthesize pure and mixed nano-structured metal oxides, aimed to contribute to the development of high performances chemical sensors. In this account, our own work on the synthesis of nanosized semi-conducting metal oxides through non conventional sol-gel methods (sol-gel in non-aqueous solvents, starch-aided sol-gel techniques, gel-combustion and reactive microemulsion) to obtain materials with un-precedent nanostructure and enhanced gas sensing-properties, is reviewed. Potential applications of these materials for gas sensors in the automotive and biomedical areas will be also illustrated