abstract
As nanomaterials are dominating 21st century's scene, multiple functionality in a single (nano)structure is becoming very appealing. Inspired by the Land of the Rising Sun, we designed a bifunctional (gas-sensor/photochromic) nanornaterial made with TiO2 whose surface was simultaneously decorated with copper and silver (the Cu/Ag molars ratio being 3:1). This nanomatenal outperformed previous state-of-the-art TiO2-based sensors for the detection of acetone, as well as the Cu-TiO2-based photochromic material. It indeed possessed splendid sensitivity toward acetone (detection limit of 100 ppb, 5 times lower than previous state-of-the-art TiO2-based acetone sensors), as well as reduced response/recovery times at very low working temperature, 150 degrees C, for acetone sensing. Still, the same material showed itself to be able to (reversibly) change in color when stimulated by both UV-A and, most remarkably, visible light. Indeed, the visible light photochromic performance was almost 3 times faster compared to the standard Cu-TiO2 photochromic material-that is, 4.0 min versus 10.8 min, respectively. It was eventually, proposed that the photochromic behavior was triggered by different mechanisms, depending on the light source used.
keywords
PHOTOCATALYTIC ACTIVITY; TIO2 NANOPARTICLES; THIN-FILMS; ANATASE; SENSORS; NANOSTRUCTURES; ACETONE; ETHANOL; RUTILE; METAL
subject category
Chemistry
authors
Tobaldi, DM; Leonardi, SG; Movlaee, K; Lajaunie, L; Seabra, MP; Arena, R; Neri, G; Labrincha, JA
our authors
David Maria Tobaldi
Researcher
João António Labrincha Baptista
Full professor
Maria Paula Seabra
Assistant Professoracknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. The STEM measurements were performed in the Laboratorio de Microscopias Avanzadas (LMA) at the Instituto de Nanociencia de Aragon (INA)-Universidad de Zaragoza (Spain). R.A. gratefully acknowledges the support from the Spanish Ministerio de Economia y Competitividad (MAT2016-79776-P), from the Government of Aragon, and the European Social Fund under the project "Construyendo Europa desde Aragon" 2014-2020 (grant number E/26).