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Author |
Barreca, D.; Carraro, G.; Maccato, C.; Altantzis, T.; Kaunisto, K.; Gasparotto, A. |
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Title |
Controlled Growth of Supported ZnO Inverted Nanopyramids with Downward Pointing Tips |
Type |
A1 Journal article |
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Year  |
2018 |
Publication |
Crystal growth & design |
Abbreviated Journal |
Cryst Growth Des |
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Volume |
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Pages |
acs.cgd.8b00198 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
High purity porous ZnO nanopyramids with controllable properties are grown on their tips on
Si(100) substrates by means of a catalyst-free vapor phase deposition route in a wet oxygen
reaction environment. The system degree of preferential [001] orientation, as well as
nanopyramid size, geometrical shape and density distribution, can be finely tuned by varying the
growth temperature between 300 and 400°C, whereas higher temperatures lead to more compact
systems with a three-dimensional (3D) morphology. A growth mechanism of the obtained ZnO
nanostructures based on a self-catalytic vapor-solid (VS) mode is proposed, in order to explain
the evolution of nanostructure morphologies as a function of the adopted process conditions. The
results obtained by a thorough chemico-physical characterization enable to get an improved
control over the properties of ZnO nanopyramids grown by this technique. Taken together, they
are of noticeable importance not only for fundamental research on ZnO nanomaterials with
controlled nano-organization, but also to tailor ZnO functionalities in view of various potential
applications. |
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Wos |
000429508200073 |
Publication Date |
2018-03-06 |
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Edition |
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ISSN |
1528-7483 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.055 |
Times cited |
6 |
Open Access |
OpenAccess |
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Notes |
This work has been supported by Padova University ex-60% 2015–2017, P-DiSC #03BIRD2016-UNIPD projects and ACTION post-doc fellowship. T. A. acknowledges a postdoctoral grant from the Research Foundation Flanders (FWO, Belgium). Thanks are also due to Dr. Rosa Calabrese (Department of Chemical Sciences, Padova University, Italy) and to Dr. T.-P. Ruoko (Department of Chemistry and Bioengineering, Tampere University of Technology, Finland) for skilful technical support. |
Approved |
Most recent IF: 4.055 |
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Call Number |
EMAT @ emat @c:irua:149514 |
Serial |
4904 |
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Author |
Barreca, D.; Carraro, G.; Gasparotto, A.; Maccato, C.; Altantzis, T.; Sada, C.; Kaunisto, K.; Ruoko, T.-P.; Bals, S. |
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Title |
Vapor Phase Fabrication of Nanoheterostructures Based on ZnO for Photoelectrochemical Water Splitting |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Advanced Materials Interfaces |
Abbreviated Journal |
Adv Mater Interfaces |
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Volume |
4 |
Issue |
4 |
Pages |
1700161 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Nanoheterostructures based on metal oxide semiconductors have emerged
as promising materials for the conversion of sunlight into chemical energy.
In the present study, ZnO-based nanocomposites have been developed by
a hybrid vapor phase route, consisting in the chemical vapor deposition
of ZnO systems on fluorine-doped tin oxide substrates, followed by the
functionalization with Fe2O3 or WO3 via radio frequency-sputtering. The
target systems are subjected to thermal treatment in air both prior and after
sputtering, and their properties, including structure, chemical composition,
morphology, and optical absorption, are investigated by a variety of characterization
methods. The obtained results evidence the formation of highly
porous ZnO nanocrystal arrays, conformally covered by an ultrathin Fe2O3
or WO3 overlayer. Photocurrent density measurements for solar-triggered
water splitting reveal in both cases a performance improvement with respect
to bare zinc oxide, that is mainly traced back to an enhanced separation of
photogenerated charge carriers thanks to the intimate contact between the
two oxides. This achievement can be regarded as a valuable result in view of
future optimization of similar nanoheterostructured photoanodes. |
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Wos |
000411525700007 |
Publication Date |
2017-05-15 |
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Series Issue |
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Edition |
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ISSN |
2196-7350 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.279 |
Times cited |
30 |
Open Access |
OpenAccess |
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Notes |
The authors kindly acknowledge the financial support under Padova University ex-60% 2013–2016, P-DiSC #SENSATIONAL BIRD2016- UNIPD projects and the post-doc fellowship ACTION. S.B. acknowledges financial support from the European Research Council (Starting Grant No. COLOURATOM 335078) and T.A. acknowledges funding from the Research Foundation Flanders (FWO, Belgium) through a postdoctoral grant. Many thanks are also due to Dr. Rosa Calabrese (Department of Chemistry, Padova University, Italy) for experimental assistance. (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); saraecas; ECAS_Sara; |
Approved |
Most recent IF: 4.279 |
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Call Number |
EMAT @ emat @c:irua:146104UA @ admin @ c:irua:146104 |
Serial |
4731 |
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Author |
Barreca, D.; Carraro, G.; Gasparotto, A.; Maccato, C.; Warwick, M.E.A.; Kaunisto, K.; Sada, C.; Turner, S.; Gönüllü, Y.; Ruoko, T.-P.; Borgese, L.; Bontempi, E.; Van Tendeloo, G.; Lemmetyinen, H.; Mathur, S. |
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Title |
Fe2O3-TiO2Nano-heterostructure Photoanodes for Highly Efficient Solar Water Oxidation |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Advanced Materials Interfaces |
Abbreviated Journal |
Adv Mater Interfaces |
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Volume |
2 |
Issue |
2 |
Pages |
1500313 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Harnessing solar energy for the production of clean hydrogen by photoelectrochemical water splitting represents a very attractive, but challenging approach for sustainable energy generation. In this regard, the fabrication of Fe2O3–TiO2 photoanodes is reported, showing attractive performances [≈2.0 mA cm−2 at 1.23 V vs. the reversible hydrogen electrode in 1 M NaOH] under simulated one-sun illumination. This goal, corresponding to a tenfold photoactivity enhancement with respect to bare Fe2O3, is achieved by atomic layer deposition of TiO2 over hematite (α-Fe2O3) nanostructures fabricated by plasma enhanced-chemical vapor deposition and final annealing at 650 °C. The adopted approach enables an intimate Fe2O3–TiO2 coupling, resulting in an electronic interplay at the Fe2O3/TiO2 interface. The reasons for the photocurrent enhancement determined by TiO2 overlayers with increasing thickness are unraveled by a detailed chemico-physical investigation, as well as by the study of photogenerated charge carrier dynamics. Transient absorption spectroscopy shows that the increased photoelectrochemical response of heterostructured photoanodes compared to bare hematite is due to an enhanced separation of photogenerated charge carriers and more favorable hole dynamics for water oxidation. The stable responses obtained even in simulated seawater provides a feasible route in view of the eventual large-scale generation of renewable energy. |
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Wos |
000368914700011 |
Publication Date |
2015-09-03 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2196-7350; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.279 |
Times cited |
56 |
Open Access |
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Notes |
The authors kindly acknowledge the fi nancial support under the FP7 project “SOLAROGENIX” (NMP4-SL-2012-310333), as well as Padova University ex-60% 2012–2014 projects, Grant No. CPDR132937/13 (SOLLEONE), and Regione Lombardia-INSTM ATLANTE projects. S.T. acknowledges the FWO Flanders for a postdoctoral scholarship. |
Approved |
Most recent IF: 4.279; 2015 IF: NA |
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Call Number |
c:irua:129201 |
Serial |
3957 |
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Author |
Barreca, D.; Carraro, G.; Warwick, M.E.A.; Kaunisto, K.; Gasparotto, A.; Gombac, V.; Sada, C.; Turner, S.; Van Tendeloo, G.; Maccato, C.; Fornasiero, P.; |
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Title |
Fe2O3-TiO2 nanosystems by a hybrid PE-CVD/ALD approach : controllable synthesis, growth mechanism, and photocatalytic properties |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
CrystEngComm |
Abbreviated Journal |
Crystengcomm |
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Volume |
17 |
Issue |
17 |
Pages |
6219-6226 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Supported Fe2O3–TiO2 nanocomposites are fabricated by an original vapor phase synthetic strategy, consisting of the initial growth of Fe2O3 nanosystems on fluorine-doped tin oxide substrates by plasma enhanced-chemical vapor deposition, followed by atomic layer deposition of TiO2 overlayers with variable thickness, and final thermal treatment in air. A thorough characterization of the target systems is carried out by X-ray diffraction, atomic force microscopy, field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. High purity nanomaterials characterized by the co-presence of Fe2O3 (hematite) and TiO2 (anatase), with an intimate Fe2O3–TiO2 contact, are successfully obtained. In addition, photocatalytic tests demonstrate that, whereas both single-phase oxides do not show appreciable activity, the composite systems are able to degrade methyl orange aqueous solutions under simulated solar light, and even visible light, with an efficiency directly dependent on TiO2 overlayer thickness. This finding opens attractive perspectives for eventual applications in wastewater treatment. |
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Wos |
000358915300018 |
Publication Date |
2015-07-23 |
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ISSN |
1466-8033; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.474 |
Times cited |
25 |
Open Access |
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Notes |
The research leading to these results has received funding from the FP7 project “SOLAROGENIX” IJNMP4-SL-2012- 310333), as well as from Padova University ex-60% 2012–2015 projects, grant no. CPDR132937/13 (SOLLEONE), and Regione Lombardia-INSTM ATLANTE projects. S. T. acknowledges the FWO Flanders for a post-doctoral scholarship. Thanks are also due to Prof. S. Mathur and Dr. Y. Gönüllü (Department of Chemistry, Cologne University, Germany) for their precious help and assistance in ALD depositions, and to Prof. E. Bontempi (Chemistry for Technologies Laboratory, Brescia University, Italy) for XRD analyses. |
Approved |
Most recent IF: 3.474; 2015 IF: 4.034 |
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Call Number |
c:irua:127237 |
Serial |
3531 |
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Author |
Warwick, M.E.A.; Kaunisto, K.; Barreca, D.; Carraro, G.; Gasparotto, A.; Maccato, C.; Bontempi, E.; Sada, C.; Ruoko, T.P.; Turner, S.; Van Tendeloo, G.; |
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Title |
Vapor phase processing of \alpha-Fe2O3 photoelectrodes for water splitting : an insight into the structure/property interplay |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
Acs Appl Mater Inter |
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Volume |
7 |
Issue |
7 |
Pages |
8667-8676 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
Harvesting radiant energy to trigger water photoelectrolysis and produce clean hydrogen is receiving increasing attention in the search of alternative energy resources. In this regard, hematite (alpha-Fe2O3) nanostructures with controlled nano-organization have been fabricated and investigated for use as anodes in photoelectrochemical (PEC) cells. The target systems have been grown on conductive substrates by plasma enhanced-chemical vapor deposition (PE-CVD) and subjected to eventual ex situ annealing in air to further tailor their structure and properties. A detailed multitechnique approach has enabled to elucidate between system characteristics and the generated photocurrent. The present alpha-Fe2O3 systems are characterized by a high purity and hierarchical morphologies consisting of nanopyramids/organized dendrites, offering a high contact area with the electrolyte. PEC data reveal a dramatic response enhancement upon thermal treatment, related to a more efficient electron transfer. The reasons underlying such a phenomenon are elucidated and discussed by transient absorption spectroscopy (TAS) studies of photogenerated charge carrier kinetics, investigated on different time scales for the first time on PE-CVD Fe2O3 nanostructures. |
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Wos |
000353931300037 |
Publication Date |
2015-04-08 |
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ISSN |
1944-8244;1944-8252; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.504 |
Times cited |
51 |
Open Access |
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Notes |
246791 Countatoms; Fwo |
Approved |
Most recent IF: 7.504; 2015 IF: 6.723 |
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Call Number |
c:irua:126059 |
Serial |
3836 |
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