Rhodium as efficient additive for boosting acetone sensing by TiO2 nanocrystals : Beyond the classical view of noble metal additives

• Anatase TiO2 nanocrystals were prepared by solvothermal synthesis and modified by in- situ generated Rh nanoparticles, with a starting nominal Rh:Ti atomic concentration of 0.01 and 0.05. After heat-treatment at 400 °C the TiO2 host was still in the anatase crystallographic phase, embedding Rh nanoparticles homogeneously distributed and whose surface had been oxidized to Rh2O3, as established by X-ray diffraction, Transmission Electron Microscopy and X-ray Photoelectron spectroscopy. Moreover, Rh seemed also homogeneously distributed in elemental form or as Rh2O3 nanoclusters. The acetone sensing properties of the resulting materials were enhanced by Rh addition, featuring a response increase of one order of magnitude at the best operating temperature of 300 °C. Moreover, Rh addition enlarged the detection range down to 10 ppm whereas pure TiO2 was not able of giving an appreciable response already at a concentration as high as 50 ppm. From the sensing data, the enhancement of the sensor response was attributed to the finely dispersed Rh species and not to the oxidized Rh nanocrystals.

Subject headings

NATURVETENSKAP  -- Fysik -- Annan fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Other Physics Topics (hsv//eng)

Keyword

TiO2 nanocrystals

Acetone sensing

Rhodium

Noble metal additives

Solvothermal synthesis

Experimentell fysik

Experimental Physics

Publication and Content Type

ref (subject category)

art (subject category)