The major drawback of oxide-based sensors is the lack of selectivity. In this context, Snx Ti1−x O2 /graphene oxide (GO)-based materials were synthesized via a simple hydrothermal route, varying the titanium content in the tin dioxide matrix. Then, toluene and acetone gas sensing performances of the as-prepared sensors were systematically investigated. Specifically, by using 32:1 SnO2 /GO and 32:1 TiO2 /GO, a greater selectivity towards acetone analyte, also at room temperature, was obtained even at ppb level. However, solid solutions possessing a higher content of tin relative to titanium (as 32:1 Sn0.55 Ti0.45 O2 /GO) exhibited higher selectivity towards bigger and non-polar molecules (such as toluene) at 350◦ C, rather than acetone. A deep experimental investigation of structural (XRPD and Raman), morphological (SEM, TEM, BET surface area and pores volume) and surface (XPS analyses) properties allowed us to give a feasible explanation of the different selectivity. Moreover, by exploiting the UV light, the lowest operating temperature to obtain a significant and reliable signal was 250◦ C, keeping the greater selectivity to the toluene analyte. Hence, the feasibility of tuning the chemical selectivity by engineering the relative amount of SnO2 and TiO2 is a promising feature that may guide the future development of miniaturized chemoresistors.

Exploring SNx ti1−x O2 solid solutions grown onto graphene oxide (GO) as selective toluene gas sensors

Cerrato G.;Giordana A.;
2020

Abstract

The major drawback of oxide-based sensors is the lack of selectivity. In this context, Snx Ti1−x O2 /graphene oxide (GO)-based materials were synthesized via a simple hydrothermal route, varying the titanium content in the tin dioxide matrix. Then, toluene and acetone gas sensing performances of the as-prepared sensors were systematically investigated. Specifically, by using 32:1 SnO2 /GO and 32:1 TiO2 /GO, a greater selectivity towards acetone analyte, also at room temperature, was obtained even at ppb level. However, solid solutions possessing a higher content of tin relative to titanium (as 32:1 Sn0.55 Ti0.45 O2 /GO) exhibited higher selectivity towards bigger and non-polar molecules (such as toluene) at 350◦ C, rather than acetone. A deep experimental investigation of structural (XRPD and Raman), morphological (SEM, TEM, BET surface area and pores volume) and surface (XPS analyses) properties allowed us to give a feasible explanation of the different selectivity. Moreover, by exploiting the UV light, the lowest operating temperature to obtain a significant and reliable signal was 250◦ C, keeping the greater selectivity to the toluene analyte. Hence, the feasibility of tuning the chemical selectivity by engineering the relative amount of SnO2 and TiO2 is a promising feature that may guide the future development of miniaturized chemoresistors.
10
4
761
776
Chemoresistor; Graphene oxide; Metal oxide solid solutions; Room temperature sensing; Selectivity; Sensitivity; Volatile organic compounds
Pargoletti E.; Verga S.; Chiarello G.L.; Longhi M.; Cerrato G.; Giordana A.; Cappelletti G.
File in questo prodotto:
File Dimensione Formato  
Nanomaterials-2020_Cerrato_2.pdf

Accesso aperto

Descrizione: pdf editoriale
Tipo di file: PDF EDITORIALE
Dimensione 3.52 MB
Formato Adobe PDF
3.52 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1768551
Citazioni
  • ???jsp.display-item.citation.pmc??? 6
  • Scopus 12
  • ???jsp.display-item.citation.isi??? 13
social impact