| 1. |
|
|
| 2. |
- Benetti, Daniele, et al.
(författare)
-
Functionalized multi-wall carbon nanotubes/TiO2 composites as efficient photoanodes for dye sensitized solar cells
- 2016
-
Ingår i: Journal of Materials Chemistry C. - 2050-7526 .- 2050-7534. ; 4:16, s. 3555-3562
-
Tidskriftsartikel (refereegranskat)abstract
- We report on the effects of incorporation of different concentrations of carboxyl group (COOH)-functionalized multi-wall carbon nanotubes (F-MWCNTs) into TiO2 active layers for dye-sensitized solar cells (DSSCs). Standard DSSCs with bare TiO2 exhibit a photo-conversion efficiency (PCE) of 6.05% and a short circuit current density (Jsc) of 13.3 mA cm−2. The presence of 2 wt% F-MWCNTs in the photoanodes increases the PCE up to 7.95% and Jsc up to 17.5 mA cm−2. The photoanodes were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. The electrochemical behaviour of the solar cells was investigated by electrochemical impedance spectroscopy (EIS). We attribute the improved performances to the combined effect of increased dye loading and reduced charge recombination (as clarified by dye loading and EIS measurements), due to the conformal coverage of F-MWCNTs, which allows fast and efficient charge collection in operating solar cells. These results can help in improving the PCE in DSSCs in an elegant and straightforward way, minimizing the need of additional steps (e.g. pre- and post-treatment with TiCl4) for photoanode preparation.
|
|
| 3. |
- Bianchi, F., et al.
(författare)
-
Characterisation of the volatile profile of orange juice contaminated with Alicyclobacillus acidoterrestris
- 2010
-
Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 123:3, s. 653-658
-
Tidskriftsartikel (refereegranskat)abstract
- A rapid and reliable analytical method, based on the characterisation of the volatile profile by dynamic headspace extraction followed by gas chromatography mass-spectrometry, was developed in order to early detect Alicyclobacillus acidoterrestris spoilage in orange juice. Gas chromatographic peak areas were submitted to multivariate statistical analysis (principal component and linear discriminant analysis) in order to visualise clusters within samples and to detect the volatile compounds able to differentiate contaminated from not-contaminated samples. Significant differences in the volatile profile of the analysed samples were found, assessing the reliability of the proposed method to detect the A. acidoterrestris contamination in orange juice.Neither guaiacol nor 2,6-dibromophenol, usually regarded as A. acidoterrestris contamination markers, were detected in the analysed samples.
|
|
| 4. |
- Bianchi, F., et al.
(författare)
-
Differentiation of the volatile profile of microbiologically contaminated canned tomatoes by dynamic headspace extraction followed by gas chromatography-mass spectrometry analysis
- 2009
-
Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 77:3, s. 962-970
-
Tidskriftsartikel (refereegranskat)abstract
- The aromatic profile of microbiologically contaminated canned tomatoes was analyzed by the dynamic headspace extraction technique coupled with gas chromatography-mass spectrometry. Canned tomatoes contaminated with Escherichia coli, Saccharomyces cerevisiae and Aspergillus carbonarius were analyzed after 2 and 7 days. About 100 volatiles were detected, among which alcohols, aldehydes and ketones were the most abundant compounds. Gas chromatographic peak areas were used for statistical purposes. First, principal component analysis was carried out in order to visualize data trends and clusters. Then, linear discriminant analysis was performed in order to detect the set of volatile compounds ables to differentiate groups of analyzed samples. Five volatile compounds, i.e. ethanol, beta-myrcene,o-methyl styrene, 6-methyl-5-hepten-2-ol and 1-octanol, were found to be able to better discriminate between uncontaminated and contaminated samples. Prediction ability of the calculated model was estimated to be 100% by the "leave-one-out" cross-validation. An electronic nose device was then used to analyze the same contaminated and not contaminated canned tomato samples. Preliminary results were compared with those obtained by dynamic headspace gas chromatography-mass spectrometry, showing a good agreement.
|
|
| 5. |
- Braga, Antonio, et al.
(författare)
-
Panchromatic sensitized solar cells based on metal sulfide quantum dots grown directly on nanostructured TiO2 electrodes
- 2011
-
Ingår i: Journal of Physical Chemistry Letters. - : American Chemical Society (ACS). - 1948-7185. ; 2:5, s. 454-460
-
Tidskriftsartikel (refereegranskat)abstract
- The use of narrow band gap semiconductors such as PbS may expand the light absorption range to the near-infrared region in quantum-dot-sensitized solar cells (QDSCs), increasing the generated photocurrent. However, the application of PbS as a sensitizer in QDSCs causes some problems of stability and high recombination. Here, we show that the direct growth of a CdS coating layer on previously deposited PbS by the simple method of successive ionic layer adsorption and reaction (SILAR) minimizes these problems. A remarkable short-circuit current density for PbS/CdS QDSCs is demonstrated, ∼11 mA/cm2, compared to that of PbS QDSCs, with photocurrents lower than 4 mA/cm2, using polysulfide electrolyte in both cells. The cell efficiency reached a promising 2.21% under 1 sun of simulated irradiation (AM1.5G, 100 mW/cm2). Enhancement of the solar cell performance beyond the arithmetic addition of the efficiencies of the single constituents (PbS and CdS) is demonstrated for the nanocomposite PbS/CdS configuration. PbS dramatically increases the obtained photocurrents, and the CdS coating stabilizes the solar cell behavior. © 2011 American Chemical Society.
|
|
| 6. |
- Comini, Elisabetta, et al.
(författare)
-
Metal oxide nanoscience and nanotechnology for chemical sensors
- 2013
-
Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 179, s. 3-20
-
Tidskriftsartikel (refereegranskat)abstract
- This paper focuses on the capabilities and development prospects of nanostructured metal oxides (MOX) representing the most versatile and richest class of materials in terms of electronic structure and structural, chemical, and physical properties. MOX nano-materials with controlled composition, surface terminations, and crystalline structures to be used as chemical sensors as a new area in analytical chemistry and instrument engineering are discussed. Their principles of operation, and basic characteristics are outlined and main applications of MOX sensor technology are presented. © 2012 Elsevier B.V. All rights reserved.
|
|
| 7. |
- Concina, Isabella, et al.
(författare)
-
Alicyclobacillus spp Detection in soft drinks by Electronic Nose
- 2010
-
Ingår i: Food Research International. - : Elsevier BV. - 0963-9969 .- 1873-7145. ; 43:8, s. 2108-214
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper the skill of an electronic nose to early diagnose the natural contamination by Alicyclobacillus spp in commercial flavoured drinks is presented The instrument was able to identify contaminated products at very low bacterial loads (tens of copies/ml) with an excellent classification rate (almost 100%) The identification of Alicyclobacillus spp by means of the electronic nose was not based on the analysis of the secondary metabolites as it is done by classical analytical techniques thus allowing a surprising capability in recognising the contaminated products at early stage of growth This study strongly suggests the use of the Electronic Noses as screening tools in industrial quality control laboratories but at the same time it underlines some limits still present in the technology
|
|
| 8. |
- Concina, Isabella
(författare)
-
An Old Material for a New World: Prussian Blue and Its Analogues as Catalysts for Modern Needs
- 2024
-
Ingår i: Inorganics. - : Multidisciplinary Digital Publishing Institute (MDPI). - 2304-6740. ; 12:4
-
Forskningsöversikt (refereegranskat)abstract
- Prussian blue analogues (PBAs) have recently emerged as effective materials in different functional applications, ranging from energy storage to electrochemical water splitting, thence to more “traditional” heterogeneous catalysis. Their versatility is due to their open framework, compositional variety, and fast and efficient internal charge exchange, coupled with a self-healing ability that makes them unique. This review paper presents and discusses the findings of the last decade in the field of the catalytic and photocatalytic application of PBAs in water remediation (via the degradation of organic pollutants and heavy metal removal) and the catalytic oxidation of organics and production or organic intermediates for industrial synthesis. Analysis of the catalytic processes is approached from a critical perspective, highlighting both the achievements of the research community and the limits still affecting this field.
|
|
| 9. |
|
|
| 10. |
- Concina, Isabella, et al.
(författare)
-
Early detection of microbial contamination in processed tomatoes by electronic nose
- 2009
-
Ingår i: Food Control. - : Elsevier BV. - 0956-7135 .- 1873-7129. ; 20:10, s. 873-880
-
Tidskriftsartikel (refereegranskat)abstract
- Microbial contamination can easily affect processed tomato, thus determining both organoleptic adulterations and potential health risks for customers. Innovative techniques for a rapid and reliable diagnose of spoilage, such as electronic nose technology, are highly requested in order to guarantee food safety and to improve production. In this work canned peeled tomatoes were artificially spoiled with different kinds of microbial flora and then were analyzed by means of an electronic nose based on thin film metal oxide gas sensors. Preliminary analyses by dynamic-headspace gas chromatographic-mass spectrometry showed significant differences in the semi-quantitative volatile compounds profile of spoiled tomato samples just after few hours from contamination, thus suggesting to employ the electronic nose for an early diagnose of microbial presence. The electronic nose was indeed able to reveal contamination, even at early stages depending on the type of contaminant (e.g. for Saccharomyces cerevisiae and Escherichia coli), and to recognize spoiled tomato samples with good classification performances.
|
|
