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Istituto sull'inquinamento atmosferico

Torna all'elenco Contributi in atti di convegno anno 2016

Contributo in atti di convegno

Tipo: Presentazione

Titolo: Titania Nanofibres: a unique solution for a lot of sensing applications

Anno di pubblicazione: 2016

Formato: Elettronico

Autori: Macagnano Antonella

Affiliazioni autori: IIA-CNR

Autori CNR:

  • ANTONELLA MACAGNANO

Lingua: inglese

Abstract: Titania nanofibres grown by electrospinning technology combine intrinsic semiconducting properties with a huge surface area, thus providing a great potential to such material for a lot of applications. Among the TiO2 crystal phases, anatase is surely the most photoactive one, thus it is expected to be the best candidate for designing sensor, optoelectronic and catalytic devices. As n-type semiconductor, titania nanofibres have been widely investigated and used for detecting several atmospheric pollutants at both high and room temperature, after the addition of organic and inorganic dopants. Exploiting the effect of titania photoconductivity, under continuous irradiation of ultra violet light, current changes upon gas interaction (NH3, NO2) were reported at room temperature. The fibres doping by metal nanoparticles (MeNPs) improved the sensing performances of titania (such as selectivity and sensitivity) under UV. In fact, the investigated chemosensors based on Pt-TiO2 nanofibres at room temperature showed an enhancement of the photoconductivity when H2 gas traces were flowed over the sensor, resulting from a combination of the features of photoconduction of titania with the photocatalytic activity of the NPs. The functionalization of the fibres with organic conducting polymers, such as PEDOT and PANi, allowed the creation of highly performing devices to detect, in lung exhaled, gases related to inflammatory processes, such as asthma and kidney diseases. Recently, Au/TiO2 nanocomposite layers have been investigated by the author's group also as potential conductive sensors to detect elemental mercury at room temperature in the atmosphere. Mercury (Hg) is indeed a global pollutant that affects human and ecosystem health. Because of high sensitivity combined with low maintenance, easy of handling and low fabrication costs, such sensors resulted as promising candidates to detect mercury in proximity of polluted areas. The photocatalytic properties of titania allowed gold nanoparticles to selectively grow on the nanofibrous scaffold from HAuCl4 (tetrachloroauric acid) as a precursor in a solution, under UV-light irradiation. However a great exposure time was necessary to trap enough mercury in order to get observable electrical signals. Thus, the amazing properties of titania were further employed in distinct strategies to improve the sensing features of the material and the resulting sensors. In the former strategy, rougher nanofibrous layers of titania were created, in order to greatly increase the number of gold nucleation sites. This finding was achieved by adding an aliquot of a non-ionic surfactant (Triton X) in the freshly prepared electrospun solution. SEM, AFM, TEM and HR-TEM analyses were carried out to characterise the morphology and the nano-sized structures of such composite nanofibres. It is known that the sensor response depends on the number of mercury atoms adsorbed on its sensitive surface. The increase in the global number of binding sites on the electrospun fabric was, then, expected to be successful in improving the sensor performances. In the latter strategy, UVlight (365 nm) was applied on the nanocomposite material in order to enable titania to cooperate with gold in mercury entrapment and then enlarge the properties of the sensing layer. An overview of optical and electrical features of titania nanofibres and its potentials as smart scaffold for advanced sensors is here reported and discussed.

Lingua abstract: inglese

Pagine da: 23

Pagine a: 23

Pagine totali: 1

Referee: Sģ: Internazionale

Stato della pubblicazione: Published version

Parole chiave:

  • nanofibres
  • titania
  • sensors

Congresso nome: COST MP1206: 6th INTERNATIONAL SEMINAR ON MODERN POLYMERIC MATERIALS FOR ENVIRONMENTAL APPLICATIONS, 27-29 April, 2016, Kraków, POLAND

Congresso luogo: Krakow, Poland

Congresso data: 27-29 April 2016

Congresso rilevanza: Internazionale

Congresso relazione: Su invito

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