• Smart surfaces for environmental remediation. Highly efficient photocatalytic nanocomposites incorporating metal oxides and graphene related materials.
  • Guidetti, Gloria <1990>

Subject

  • CHIM/03 Chimica generale e inorganica

Description

  • After the Kyoto Protocol, the World Health Organization estimated in2016 that up to date one out of every nine deaths was related to outdoor/indoor air pollution[1]. As a consequence the World’s population expressed the need to have Healthier Cities and the design of new technologies to eliminate air pollutants[e.g. nitrogen oxides(NOx)and organics] by using natural sunlight, and their integration into smart cities became the centre of an ever increasing research[2]. Photocatalysts based on TiO2 are already on the market[3] and embedded in commercial products, such as cement[4]. However, they work only with the UV light λ<380nm [5], with a significant drop of performance in the visible[6]. In this work I enhanced and extend the TiO2 spectral activity by creating hybrid photocatalysts with organics (e.g perylenes), or graphene and related materials (GRM-PCs)(e.g. graphene, MoS2, WS2 and red phosphorous (RP)). We test the photocatalytic activity by monitoring the dye degradation(rhodamineB,(RhB))caused by GRM-PCs after a fixed irradiation time with respect to pristine TiO2. GRM-PCs based on TiO2 mixed with exfoliated graphite (TiO2-Gr) or with RP show ~90% higher photocatalytic activity, in terms of dye degradation, than pristine TiO2, after 20 min UV-Vis irradiation. Tests in the visible range (400<λ<800nm) how that RP is ideal for indoor applications, with a~800%improvement of photocatalytic activity with respect to TiO2, after 40min vis-light irradiation (5mW/cm2). The photocatalytic activity of TiO2-Gr is tested after mixing in an industrial concrete matrix, resulting in an increment of dye degradation of50%. These data underpin the potential of GRM-PCs for smart surfaces. In a city such as Milan, covering 15% of urban surfaces with TiO2-based cement photocatalysts would enable a reduction in pollution~50%. An efficient dispersion of the new cementitious coatings I have developed will allow to reach an abatement of the pollution of90% with2.5% surface covering. [1]http://www.who.int.[2]H.Tong,Adv.Mater,24,229(2012)[3]http://www.ti-line.net/[4]http://www.italcementigroup.com/ITA/[5]M.R.Hoffmann,Chem.Rev.,95,69(1995)[6]R.Asahi,Science,293,269,(2001)

Date

  • 2018-05-09

Type

  • Doctoral Thesis
  • PeerReviewed

Format

  • application/pdf

Identifier

urn:nbn:it:unibo-27548

Guidetti, Gloria (2018) Smart surfaces for environmental remediation. Highly efficient photocatalytic nanocomposites incorporating metal oxides and graphene related materials., [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Chimica , 30 Ciclo. DOI 10.6092/unibo/amsdottorato/8572.

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