C. Piccirillo | Universidade Católica Portuguesa (original) (raw)
Papers by C. Piccirillo
Materials Science and Engineering C 71 (2017) 141–149, Dec 15, 2016
The development of innovative, safe and non-photocatalytic sunscreens is urgently needed, as it i... more The development of innovative, safe and non-photocatalytic sunscreens is urgently needed, as it is essential to have sunscreen filters offering appropriate UV protection without damaging the environment and/or generating free radicals when in contact with the skin. Hydroxyapatite (Ca10(PO4)6(OH)2 , HAp) when substituted with iron has UV protection properties and is not photocatalytic; HAp was used to make a sunscreen filter by treating cod fish bones in an iron-containing solution, and then calcining them at 700 °C. Here we present a systematic and advanced study on this material, to obtain a sunscreen with improved UV absorbing properties. Bones were treated with three different iron salts-Fe(II) chloride, Fe(II) lactate and Fe(III) nitrate-under various pH conditions. Results showed that Fe(II) chloride in basic pH led to the most effective iron inclusion. High energy ball milling or ultrasound were investigated to increase surface area and corresponding UV absorption; high energy ball milling treatment led to the best optical properties. The optimum powders were used to formulate UV protection creams, which showed Sun Protection Factor (SPF) values significantly superior to the control cream (up to 4.1). Moreover the critical wavelength (λcrit) was >370 nm (388–389 nm) and UVA/UVB ratios were very close to 1. With these properties these sunscreens can be classified as broad UV protectors. Results also showed that combining these powders with other sunscreens (i.e. titanium dioxide), a synergic effect between the different components was also observed. This investigation showed that HAp-based sunscreens of marine origin are a valid alternative to commercial products, safe for the health of the customers and, being non-photocatalytic, do not pose a threat to the environment.
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Pharmaceutical persistent pollutants pose a serious threat to the environment. The aim of this st... more Pharmaceutical persistent pollutants pose a serious threat to the environment. The aim of this study was to use, for the first time, hydroxyapatite-based biomaterials as photocatalysts to degrade micro-pollutants. Diclofenac and fluoxetine were selected for these initial tests. Hydroxyapatite (Ca 10 (PO 4)(OH) 2 , HAp) is one of the most commonly used biomaterials/bioceramics, being a major constituent of bone. In this work sustainable HAp-based materials of marine origin, obtained from cod fish bones, were used; these photocatalysts were previously fully studied and characterised. Both single-phase HAp and HApetitania multicomponent materials (1 wt% TiO 2) were employed as UV light pho-tocatalysts, the latter showing better performance, indicated by higher degradation rates of both compounds. The HAp-titania photocatalyst showed excellent degradation of both persistent pollutants, the maximum degradation performance being 100% for fluoxetine and 92% for diclofenac, with pollutant and photocatalyst concentrations of 2 ppm and 4 g/L, respectively. Variations in features such as pollutant and photocatalyst concentrations were investigated, and results showed that generally fluoxetine was degraded more easily than diclofenac. The photocatalyst's crystallinity was not affected by the photo-degradation reaction; indeed the material exhibited good photostability, as the degradation rate did not decrease when the material was reused. Tests were also performed using actual treated wastewater; the photocatalyst was still effective, even if with lower efficiency (À20% and À4% for diclofenac and fluox-etine, respectively). TOC analysis showed high but incomplete mineralisation of the pollutants (maximum 60% and 80% for DCF and FXT, respectively).
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Journal of Photochemistry and Photobiology A: Chemistry 332 (2017) 45-53, Jan 1, 2017
This work describes the first Aerosol Assisted Chemical Vapour Deposition (AACVD) synthesis of ph... more This work describes the first Aerosol Assisted Chemical Vapour Deposition (AACVD) synthesis of photocatalytic titanium dioxide thin films embedded with synthetic hydroxyapatite, [Ca10(PO4)(OH)2], nanoparticles. The hydroxyapatite nanoparticles were prepared using a low temperature continuous hydrothermal flow synthesis method; analysis of the hydroxyapatite powder showed that it was phase pure and that the as-prepared material was made up of nano-needles. The nanoparticles were then embedded into TiO2 coatings using the AACVD technique by suspending them in a solution of the titania precursor (titanium tetra-isopropoxide). Results showed that the hydroxyapatite, although present in very low concentrations in the coatings (not detectable by XRD or Raman spectroscopy), heavily affected their morphology, depending on their concentration in the precursor solution. Tests of the photocatalytic activity of the composite films showed that the inclusion of the hydroxyapatite led to an increase in methylene blue photodegradation (up to 50% higher) and that the materials were photostable. This study shows that TiO2 coatings embedded with hydroxyapatite nanoparticles have potential as highly efficient photocatalysts.
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Journal of Electroanalytical Chemistry, 1997
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Ceramics International, 2015
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Materials Science Forum, 2008
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International Journal of Mass Spectrometry and Ion Processes, 1997
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International Journal of Mass Spectrometry and Ion Processes, 1996
The process of TiO2 evolution from titanium diisopropoxide bis-2,4-pentanedionate precursor on ni... more The process of TiO2 evolution from titanium diisopropoxide bis-2,4-pentanedionate precursor on nickel and titanium supports was followed by secondary ion mass spectrometry. Concentration depth profiles of rutile (TiO2) at higher temperatures showed completely different patterns for the two supports, indicating the influence of the base metal on the formation and properties of the oxide coating.The formation and surface accumulation of
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Thin Solid Films, 2008
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Polyhedron, 2009
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ECS Transactions, 2009
ABSTRACT A hybrid chemical vapour deposition strategy is presented as a facile route for the prod... more ABSTRACT A hybrid chemical vapour deposition strategy is presented as a facile route for the production of vanadium dioxide nano-composite thin films. The effect of the inclusion of gold nano-particles and the use of a surfactant molecule; tetraoctylammonium bromide (TOAB), is discussed. The films are fully characterised and it is shown that micro-structural changes lead to an enhancement of thermochromic properties, whilst gold nano-particles lead to a change in the films optical properties. Optical data is used in energy modelling studies to elucidate the films potential as an energy saving coating in architectural glazing.
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Solar Energy Materials and Solar Cells, 2010
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Materials Science Forum, 1997
ABSTRACT Export Date: 24 October 2012, Source: Scopus
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World Journal of Microbiology and Biotechnology, 2012
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Waste and Biomass Valorization, 2011
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Rapid Communications in Mass Spectrometry, 2000
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Rapid Communications in Mass Spectrometry, 1996
ABSTRACT Cited By (since 1996): 2, Export Date: 24 October 2012, Source: Scopus
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Rapid Communications in Mass Spectrometry, 1996
ABSTRACT The formation mechanism of an IrO2/TiO2 film electrode has been studied by secondary ion... more ABSTRACT The formation mechanism of an IrO2/TiO2 film electrode has been studied by secondary ion mass spectrometry (SIMS). A coating mixture with the composition 50% Ir+50% Ti prepared on a titanium support from an isopropanolic solution of hydrated iridium chloride and titanium bis-2,4-pentanedionate precursors was heated to specified temperatures and analysed by SIMS. Concentration depth profiles of some selected species (e.g. Cl−, O−, ClO−, TiO+, Ir+, IrO, TiO, CH, C2H, OH−) were used to follow the process of film evolution. Segregation phenomena resulting in the increased dispersity of the noble metal on the surface were identified. The results are in accordance with—and complementary to—those of former measurements by combined thermoanalytical, mass spectrometric and emission Fourier transform infrared (FTIR) techniques.
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Materials Science and Engineering C 71 (2017) 141–149, Dec 15, 2016
The development of innovative, safe and non-photocatalytic sunscreens is urgently needed, as it i... more The development of innovative, safe and non-photocatalytic sunscreens is urgently needed, as it is essential to have sunscreen filters offering appropriate UV protection without damaging the environment and/or generating free radicals when in contact with the skin. Hydroxyapatite (Ca10(PO4)6(OH)2 , HAp) when substituted with iron has UV protection properties and is not photocatalytic; HAp was used to make a sunscreen filter by treating cod fish bones in an iron-containing solution, and then calcining them at 700 °C. Here we present a systematic and advanced study on this material, to obtain a sunscreen with improved UV absorbing properties. Bones were treated with three different iron salts-Fe(II) chloride, Fe(II) lactate and Fe(III) nitrate-under various pH conditions. Results showed that Fe(II) chloride in basic pH led to the most effective iron inclusion. High energy ball milling or ultrasound were investigated to increase surface area and corresponding UV absorption; high energy ball milling treatment led to the best optical properties. The optimum powders were used to formulate UV protection creams, which showed Sun Protection Factor (SPF) values significantly superior to the control cream (up to 4.1). Moreover the critical wavelength (λcrit) was >370 nm (388–389 nm) and UVA/UVB ratios were very close to 1. With these properties these sunscreens can be classified as broad UV protectors. Results also showed that combining these powders with other sunscreens (i.e. titanium dioxide), a synergic effect between the different components was also observed. This investigation showed that HAp-based sunscreens of marine origin are a valid alternative to commercial products, safe for the health of the customers and, being non-photocatalytic, do not pose a threat to the environment.
Bookmarks Related papers MentionsView impact
Pharmaceutical persistent pollutants pose a serious threat to the environment. The aim of this st... more Pharmaceutical persistent pollutants pose a serious threat to the environment. The aim of this study was to use, for the first time, hydroxyapatite-based biomaterials as photocatalysts to degrade micro-pollutants. Diclofenac and fluoxetine were selected for these initial tests. Hydroxyapatite (Ca 10 (PO 4)(OH) 2 , HAp) is one of the most commonly used biomaterials/bioceramics, being a major constituent of bone. In this work sustainable HAp-based materials of marine origin, obtained from cod fish bones, were used; these photocatalysts were previously fully studied and characterised. Both single-phase HAp and HApetitania multicomponent materials (1 wt% TiO 2) were employed as UV light pho-tocatalysts, the latter showing better performance, indicated by higher degradation rates of both compounds. The HAp-titania photocatalyst showed excellent degradation of both persistent pollutants, the maximum degradation performance being 100% for fluoxetine and 92% for diclofenac, with pollutant and photocatalyst concentrations of 2 ppm and 4 g/L, respectively. Variations in features such as pollutant and photocatalyst concentrations were investigated, and results showed that generally fluoxetine was degraded more easily than diclofenac. The photocatalyst's crystallinity was not affected by the photo-degradation reaction; indeed the material exhibited good photostability, as the degradation rate did not decrease when the material was reused. Tests were also performed using actual treated wastewater; the photocatalyst was still effective, even if with lower efficiency (À20% and À4% for diclofenac and fluox-etine, respectively). TOC analysis showed high but incomplete mineralisation of the pollutants (maximum 60% and 80% for DCF and FXT, respectively).
Bookmarks Related papers MentionsView impact
Journal of Photochemistry and Photobiology A: Chemistry 332 (2017) 45-53, Jan 1, 2017
This work describes the first Aerosol Assisted Chemical Vapour Deposition (AACVD) synthesis of ph... more This work describes the first Aerosol Assisted Chemical Vapour Deposition (AACVD) synthesis of photocatalytic titanium dioxide thin films embedded with synthetic hydroxyapatite, [Ca10(PO4)(OH)2], nanoparticles. The hydroxyapatite nanoparticles were prepared using a low temperature continuous hydrothermal flow synthesis method; analysis of the hydroxyapatite powder showed that it was phase pure and that the as-prepared material was made up of nano-needles. The nanoparticles were then embedded into TiO2 coatings using the AACVD technique by suspending them in a solution of the titania precursor (titanium tetra-isopropoxide). Results showed that the hydroxyapatite, although present in very low concentrations in the coatings (not detectable by XRD or Raman spectroscopy), heavily affected their morphology, depending on their concentration in the precursor solution. Tests of the photocatalytic activity of the composite films showed that the inclusion of the hydroxyapatite led to an increase in methylene blue photodegradation (up to 50% higher) and that the materials were photostable. This study shows that TiO2 coatings embedded with hydroxyapatite nanoparticles have potential as highly efficient photocatalysts.
Bookmarks Related papers MentionsView impact
Journal of Electroanalytical Chemistry, 1997
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Ceramics International, 2015
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Materials Science Forum, 2008
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International Journal of Mass Spectrometry and Ion Processes, 1997
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International Journal of Mass Spectrometry and Ion Processes, 1996
The process of TiO2 evolution from titanium diisopropoxide bis-2,4-pentanedionate precursor on ni... more The process of TiO2 evolution from titanium diisopropoxide bis-2,4-pentanedionate precursor on nickel and titanium supports was followed by secondary ion mass spectrometry. Concentration depth profiles of rutile (TiO2) at higher temperatures showed completely different patterns for the two supports, indicating the influence of the base metal on the formation and properties of the oxide coating.The formation and surface accumulation of
Bookmarks Related papers MentionsView impact
Thin Solid Films, 2008
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Polyhedron, 2009
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ECS Transactions, 2009
ABSTRACT A hybrid chemical vapour deposition strategy is presented as a facile route for the prod... more ABSTRACT A hybrid chemical vapour deposition strategy is presented as a facile route for the production of vanadium dioxide nano-composite thin films. The effect of the inclusion of gold nano-particles and the use of a surfactant molecule; tetraoctylammonium bromide (TOAB), is discussed. The films are fully characterised and it is shown that micro-structural changes lead to an enhancement of thermochromic properties, whilst gold nano-particles lead to a change in the films optical properties. Optical data is used in energy modelling studies to elucidate the films potential as an energy saving coating in architectural glazing.
Bookmarks Related papers MentionsView impact
Solar Energy Materials and Solar Cells, 2010
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Materials Science Forum, 1997
ABSTRACT Export Date: 24 October 2012, Source: Scopus
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World Journal of Microbiology and Biotechnology, 2012
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Waste and Biomass Valorization, 2011
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Rapid Communications in Mass Spectrometry, 2000
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Rapid Communications in Mass Spectrometry, 1996
ABSTRACT Cited By (since 1996): 2, Export Date: 24 October 2012, Source: Scopus
Bookmarks Related papers MentionsView impact
Rapid Communications in Mass Spectrometry, 1996
ABSTRACT The formation mechanism of an IrO2/TiO2 film electrode has been studied by secondary ion... more ABSTRACT The formation mechanism of an IrO2/TiO2 film electrode has been studied by secondary ion mass spectrometry (SIMS). A coating mixture with the composition 50% Ir+50% Ti prepared on a titanium support from an isopropanolic solution of hydrated iridium chloride and titanium bis-2,4-pentanedionate precursors was heated to specified temperatures and analysed by SIMS. Concentration depth profiles of some selected species (e.g. Cl−, O−, ClO−, TiO+, Ir+, IrO, TiO, CH, C2H, OH−) were used to follow the process of film evolution. Segregation phenomena resulting in the increased dispersity of the noble metal on the surface were identified. The results are in accordance with—and complementary to—those of former measurements by combined thermoanalytical, mass spectrometric and emission Fourier transform infrared (FTIR) techniques.
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