Colorimetric gas detection by the varying thickness of a thin film of ultrasmall PTSA-coated TiO₂ nanoparticles on a Si substrate

• Urmas Joost,
• Andris Šutka,
• Meeri Visnapuu,
• Aile Tamm,
• Meeri Lembinen,
• Mikk Antsov,
• Kathriin Utt,
• Krisjanis Smits,
• Ergo Nõmmiste and
• Vambola Kisand

Beilstein J. Nanotechnol. 2017, 8, 229–236, doi:10.3762/bjnano.8.25

• . The color response is rapid and changes reversibly within seconds of exposure. The sensing element is extremely simple and cheap, and can be fabricated by common coating processes. Keywords: colorimetric gas sensing; p-toluenesulfonic acid (PTSA); TiO2 nanoparticles; Introduction The apparent color

• ultrasmall TiO2 nanoparticles (NPs) for a colorimetric gas sensor. The functional thin film is extremely simple, consisting of TiO2 NPs and the elastic binding agent p-toluenesulfonic acid (PTSA) on a Si substrate. It is not necessary to use particles with narrow size distributions of diameters in well

• and Sanchez [8] with slightly modified parameters [9][10]. Commercially available titanium(IV) butoxide (Sigma-Aldrich, reagent grade), p-toluenesulfonic acid (PTSA) (Sigma-Aldrich, reagent plus), acetylacetone (acac) (Sigma-Aldrich, reagent plus), butanol (Sigma-Aldrich) and deionised water were used