Multi-Functional Nanomaterial Group
Nanomaterials for safety: detection of toxic or flammable gases
The early gas-phase detection of flammable/harmful chemicals (such as CO, H2, CH4, NO2, O3,….) is an open challenge of utmost importance for environmental and health protection, as well as for public security issues. In particular, in military and civilian defense, great strides have been undertaken to recognize toxic and dangerous chemical warfare agents, in order to detect their use by individuals and/or terrorist organizations and prevent human exposure. In this regard, continuous efforts are devoted to the development of low-cost, miniaturized sensors with enhanced service life and optimal selectivity and stability. Nevertheless, the development of systems simultaneously endowed with all these features is still far from being completely fulfilled and represents the main bottleneck in order to meet the actual technological requirements.
It is generally recognized that the performances of solid-state gas sensors are directly dependent on the structure and spatial organization of the active material. As a consequence, nanostructured thin films, and, more recently, nanocomposites and 1D systems such as nanowires and nanobelts, have attracted a considerable interest. In this context, over the last decade the MFN group has devoted various efforts to the fabrication of the active elements for conductometric sensors based on ZnO, ZnO-TiO2, CuxO (x = 1,2), CuO-TiO2, Co3O4, ZnO-X (X = Ag, CuO), Mn3O4, MnO2.
The target materials are prepared by vapor-phase techniques, with particular attention to the engineering of suitable molecular precursors endowed with specific chemical information enabling to tailor the resulting system properties. Particular attention is dedicated to modulation of the nano-organization and to the functionalization with metal (Pt, Ag, Au) or oxide (Fe2O3, ZnO, SnO2) particles to achieve improved sensing responses, enhanced selectivity and lower detection limits at moderate working temperatures. The active materials are deposited directly onto the substrates used for the target functional applications and subjected to a thorough chemico-physical characterization, with the aim of unraveling the interrelation between properties and sensing performances and improve thus the system functional behavior.
It is generally recognized that the performances of solid-state gas sensors are directly dependent on the structure and spatial organization of the active material. As a consequence, nanostructured thin films, and, more recently, nanocomposites and 1D systems such as nanowires and nanobelts, have attracted a considerable interest. In this context, over the last decade the MFN group has devoted various efforts to the fabrication of the active elements for conductometric sensors based on ZnO, ZnO-TiO2, CuxO (x = 1,2), CuO-TiO2, Co3O4, ZnO-X (X = Ag, CuO), Mn3O4, MnO2.
The target materials are prepared by vapor-phase techniques, with particular attention to the engineering of suitable molecular precursors endowed with specific chemical information enabling to tailor the resulting system properties. Particular attention is dedicated to modulation of the nano-organization and to the functionalization with metal (Pt, Ag, Au) or oxide (Fe2O3, ZnO, SnO2) particles to achieve improved sensing responses, enhanced selectivity and lower detection limits at moderate working temperatures. The active materials are deposited directly onto the substrates used for the target functional applications and subjected to a thorough chemico-physical characterization, with the aim of unraveling the interrelation between properties and sensing performances and improve thus the system functional behavior.
