Luca Malfatti

Luca Malfatti
Università degli Studi di Sassari | UNISS · Dipartimento di Architettura, Design e Urbanistica

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163
Publications
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Publications

Publications (163)
Article
Full-text available
Heterostructures formed by anatase nanotitania and bidimensional semiconducting materials are expected to become the next-generation photocatalytic materials with an extended operating range and higher performances. The capability of fabricating optically transparent photocatalytic thin films is also a highly demanded technological issue, and incre...
Article
Due to the ever-increasing worldwide interest in the exploitation of waste vegetable oils, the development of analytical tools able to detect their adulteration with edible oils, is considered a priority for the scientific and industrial community. In this work, edible and waste vegetable oils have been analysed by Fourier Transform-InfraRed (FT-IR...
Article
Full-text available
Graphene-enhanced Raman scattering (GERS) produces enhancement of the Raman signal, which is based on chemical rather than electromagnetic mechanism such as in the surface-enhanced Raman scattering. Graphene oxide, amino- and guanidine-functionalized graphene oxide, exfoliated graphene, and commercial graphene nanoplatelets have been used to invest...
Article
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The coronavirus pandemic (COVID-19) had spread rapidly since December 2019, when it was first identified in Wuhan, China. As of April 2021, more than 130 million cases have been confirmed, with more than 3 million deaths, making it one of the deadliest pandemics in history. Different approaches must be put in place to confront a new pandemic: commu...
Article
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The polycondensation of amino acids can originate complex polymers that display fascinating structural and optical properties. Thermally induced amidation of l-lysine allows forming a branched polymer without the support of any catalyst. The polycondensation is completed at 240–250 °C; at higher temperatures, the amino acid degrades. The obtained p...
Article
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Nitrite ions pose a severe problem to human health justifying the need for fast and reliable detection of their presence in freshwater. Here we report a method to detect nitrite by photoluminescence of amino-rich carbon dots (C-dots). The dots are synthesized from p-phenylenediamine through a solvothermal treatment in ethanol. When nitrites ions ar...
Article
Hexagonal boron nitride (h-BN) nanodots of 10 nm have been synthesized via top-down route from bulk powders. A combination of ultrasonic and thermal treatments in phosphoric acid has been used to achieve edge etching and size reduction to the nanoscale. A new emission in the ultraviolet region, correlated to a characteristic infrared-active vibrati...
Article
Hexagonal boron nitride (h-BN) nanodots of 10 nm have been synthesized via top-down route from bulk powders. A combination of ultrasonic and thermal treatments in phosphoric acid has been used to achieve edge etching and size reduction to the nanoscale. A new emission in the ultraviolet region, correlated to a characteristic infrared-active vibrati...
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Palladium nanoparticles supported on zirconium titanate with cerium doping up to 10% molar (Ce‐ZT) are prepared by a facile impregnation method and characterized by several techniques. Due to electronic effects, the amount of Ce cations in a reduced oxidation state, i.e., Ce(III), is surprisingly high, more than 50% of the total cerium amount. The...
Article
Exposure to styrene is a major safety concern in the fibreglass processing industry. This compound is classified by the International Agency for Research on Cancer as a possible human carcinogen. Several types of analytical equipment exist for detecting volatile organic compounds (VOCs) in the atmosphere; however, most of them operate ex-situ or do...
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The fabrication of optically active heterostructures in the shape of mesostructured thin films is a highly challenging task. It requires an integrated process to allow in one-step incorporating the two-dimensional materials within the mesoporous ordered host without disrupting the pore organization. Hexagonal boron nitride (BN) nanosheets have been...
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Molecular structures of siloxane materials should be highly controlled for achieving advanced functionalities. However, it is still difficult to precisely control the structure of siloxane materials by the sol–gel processing. In the present study, we focused on the silanol groups in the intermediate oligomers and resultant siloxane materials as a k...
Article
With the increase of industrialization, there is an urgent need for developing technologies to detect and remove toxic pollutants from water bodies. The pollutants are often released to the environment due to the consumption of raw materials that are necessary for the production of technological goods (such as chemical and pharmaceutical compounds,...
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Carbon dots (CDs) are highly-emissive nanoparticles obtained through fast and cheap syntheses. The understanding of CDs’ luminescence, however, is still far from being comprehensive. The intense photoluminescence can have different origins: molecular mechanisms, oxidation of polyaromatic graphene-like layers, and core-shell interactions of carbonac...
Article
Carbonized polymer dots (CPDs), a peculiar type of Carbon dots, show extremely high quantum yields, making them very attractive nanostructures for application in optics and biophotonics. The origin of CPD strong photoluminescence resides in a complicated interplay of several radiative mechanisms. To understand the correlation between CPD processing...
Article
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The origin of carbon-dots (C-dots) fluorescence and its correlation with the dots structure still lack a comprehensive model. In particular, the core-shell model does not always fit with the experimental results, which, in some cases, suggest a molecular origin of the fluorescence. To gain a better insight, we have studied the response of molecular...
Article
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Citrazinic acid (CZA) is a weakly fluorescent molecular compound whose optical properties are dependent on aggregation states and chemical environment. This molecule and its derivatives have been recently identified as the source of the intense blue emission of carbon dots obtained from citric acid with a nitrogen source, such as ammonia or urea. C...
Article
Blue-emitting nitrogen-doped carbon dots (CDN) produced by a solvent-free method have been successfully incorporated into silica (SiO2) through a sol-gel procedure. By exploiting the co-gelation of the dispersed carbon dots and of the silica matrix, homogeneous distribution of the carbon dots was obtained throughout the matrix. The CDN-SiO2 composi...
Article
Dual-tethered nanosystems which combine different properties at the nanoscale represent a new fascinating frontier of research. In the present work, we present an example of dual nanosystem designed to enhance the radical scavenging performances. Fulleropyrrolidine has been bonded to cerium oxide nanoparticles (nanoceria) to form a dual tethered sy...
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Highly fluorescent blue and green-emitting carbon dots have been designed to be integrated into sol-gel processing of hybrid organic-inorganic materials through surface modification with an organosilane, 3-(aminopropyl)triethoxysilane (APTES). The carbon dots have been synthesised using citric acid and urea as precursors; the intense fluorescence e...
Article
Understanding the luminescence of carbon dots is a highly challenging task because of the complex reactions involved in the synthesis process. Several by-products form at different reaction stages and become possible sources of emission. Citrazinic acid and its derivatives, in particular, have been identified as intermediates that give rise to blue...
Article
Clean-up of crude-oil spills ranks among the major environmental remediation issues and demands for sorbents with high and stable oleophilic and hydrophobic features. Here, aerogels with durable hydrophobicity are produced by incorporating reduced graphene oxide (rGO) in highly porous silica matrices. By a sol-gel protocol, high rGO loadings are ac...
Article
Microporous organic-inorganic hybrid silica films have been designed as active platforms to realise a styrene gas sensor. The microporous film has been synthesized by using tetraethylorthosilicate and phenyltriethoxysilane as precursors and a triblock copolymer (Pluronic F127) as a template for the pores. Multilayer films have been employed to incr...
Article
Bottom-up synthesis of fluorescent boron-nitride based dots is a challenging task because an accurate design of the structure-properties relationship is, in general, difficult to achieve. Incorporation of the dots into a solid-state matrix is also another important target to develop light-emitting devices. Two-colour fluorescent boron oxynitride na...
Article
Thermal decomposition of citric acid is one of the most common syntheses of fluorescent C-dots; the reaction pathway is, however, quite complex and the details are still far from being understood. For instance, several intermediates form during the process and they also give rise to fluorescent species. In the present work, the formation of fluores...
Article
Thermal decomposition of citric acid is one of the most common syntheses of fluorescent C‐dots; the reaction pathway is, however, quite complex and the details are still far from being understood. For instance, several intermediates form during the process and they also give rise to fluorescent species. In the present work, the formation of fluores...
Article
Two nanocomposites of different layer thickness were synthesized by impregnation of a rutile titania support with a reduced ceria solution. An in situ Diffuse Reflectance Infrared Fourier-Transform Spectroscopy-Mass Spectrometry (DRIFTS-MS) study of these materials, compared with the parent single oxides, has shown remarkable differences in the int...
Article
Raman spectroscopy is one of the most sensitive analytical techniques with the possibility of reaching single molecule detection through the surface-enhanced Raman scattering (SERS). Mesoporous materials, which exhibit an organized porosity in the 2–10 nm range, represent an advanced platform for developing SERS-based systems and devices for multip...
Article
Graphene oxide/iron (III -VI) oxides nanocomposites have been produced with a fast and one-pot synthesis. K2FeO4 (Fe(VI)-based compound), obtained from a dry synthesis, has been used as a green oxidant of graphite to produce graphene oxide, avoiding the use of the toxic permanganates. Graphene oxide flakes with a low oxidation degree and decorated...
Article
The optical properties of microwave synthesized Carbon Dots dispersed in water and in mesoporous ordered silica are reported. The fluorescence characteristics of bare carbon dots are compared to the ones of nitrogen-doped samples, nitrogen doping being exploited to increase the emission efficiency. Two emission bands in the blue-green region, at ab...
Article
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A highly sensitive and selective Raman sensor has been developed by combining molecularly imprinted cavities, silver nanoparticles, and graphene oxide into a hybrid organic-inorganic film. The molecular imprinted nanocomposite material is an advanced platform that exhibits Graphene-mediated Surface-Enhanced Raman Scattering. The sensing layers have...
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MIL-88A (Fe) MOF crystals were nucleated and grown around a polymer core containing superparamagnetic nanoparticles to assemble a new class of biocompatible particles for magnetophoretic drug delivery of dopamine. The carrier enabled efficient targeted release, dopamine protection from oxidative damage, long-term delivery and improved drug delivery...
Chapter
This chapter wishes to provide the reader with some examples of composite materials obtained through integration of carbon-based nanostructures, graphene and carbon dots, into mesoporous materials and some of the issues thereof. After a brief introduction to the chemistry of graphene and its derivatives, relevant for understanding the problems asso...
Article
Full-text available
Mesoporous ordered materials, whose porosity is within the 2–50-nm range, are an ideal host for functional nanoparticles. Mesoporous thin films, in particular, offer a large variety of options for the fabrication of advanced materials and devices based on the host-guest combination of matrix nanoparticles. Nanocomposite mesoporous films embedding m...
Article
Hybrid organic-inorganic luminescent lanthanide-based nanomaterials are currently attracting great interest for a variety of applications from bioimaging/sensing to optics and photonics. Herein we present a concept model system based on purely silica-based core-shell nanoparticles (NPs) where luminescent Eu³⁺ ions are confined into a thin silica la...
Article
Graphene oxide – silver nanoparticle composites (GO-Ag) have been developed as a stable Raman sensing system. The Ag loading and concentration of GO-Ag dispersion have been optimized as a function of the Raman response. The silver nanoparticles (Ag NPs) have been well dispersed and anchored to the GO surface. The system has shown an excellent enhan...
Article
Carbon dots are an emerging class of carbon-based nanostructures produced by low-cost raw materials which exhibit a widely-tunable photoluminescence and a high quantum yield. The potential of these nanomaterials as a substitute of semiconductor quantum dots in optoelectronics and biomedicine is very high, however they need a customized chemistry to...
Article
The photoluminescence of thin films doped with fluorescent dyes, such as rhodamine 6G (Rh6G), is strongly dependent on their concentration and aggregation states. We have doped ZnO dense and mesostructured thin films with different concentrations of Rh6G. The films have been prepared via sol-gel using a block copolymer as template to obtain the mes...
Article
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Advanced optical applications of fluorescent carbon dots (C-dots) require highly integrated host-guest solid-state materials with a careful design of C-dots – matrix interface to control the optical response. We have developed a new synthesis based on the grafting of an organo-functional silane (3-glycidyloxypropyltrimethoxysilane, GPTMS) on amino-...
Article
A selective sensing platform for the organophosphate paraoxon, a highly toxic organic pollutant, has been designed and tested on water samples. A porous hybrid organic–inorganic film, synthesised using tetraethoxysilane, 1,8-bis(triethoxysilyl) octane and cetyltrimethylammonium bromide, has been molecularly imprinted with a structural analogue of p...
Article
The application of titania materials to gas sensing devices based on thin films are of limited utility because they only operate at a high working temperature and exhibit in general a low sensitivity. To overcome these constraints, a new type of oxygen sensor based on mesoporous titania thin films working at room temperature under UV irradiation ha...
Article
The present study investigated whether supplementation with different doses of cerium dioxide nanoparticles (CeO2 NPs) during in vitro maturation (IVM) of prepubertal ovine oocytes influenced their embryonic development in vitro. Cumulus–oocyte complexes derived from the ovaries of slaughtered prepubertal sheep underwent IVM with CeO2NPs (0, 44, 88...
Article
The availability of safe drinking-water at the global level is one of the biggest challenges of our century. At present, toxins and pathogens in fresh waters are responsible for more than two million deaths per year. This scenario allows understanding how the development of effective and sustainable technologies for water treatment is of pivotal im...
Article
Green synthesis is one of the hot topics in the chemistry of hybrid organic–inorganic materials. A alcohol-free sol–gel process has been developed to prepare optically transparent hybrid films from an epoxy bearing alkoxide, [2-(3,4-epoxy-cyclohexyl)-ethyl]-trimethoxysilane (ECTMS). The synthesis is simple and effective because only two components,...
Article
Enhancement of Raman scattering signal through graphene is an important property that could be exploited for producing innovative sensing devices with advanced properties. Because the enhancement of Raman scattering is due only to a chemical mechanism, the amplification of the signal is lower than that one produced by excitation of localized surfac...
Chapter
This chapter wishes to provide the reader with some examples of composite materials obtained through integration of carbon-based nanostructures, graphene and carbon dots, into mesoporous materials and some of the issues thereof. After a brief introduction to the chemistry of graphene and its derivatives, relevant for understanding the problems asso...
Article
Full-text available
The controlled growth of Ag nanoparticles into graphene–TiO2 mesoporous films has been triggered by hard X-ray exposure provided by a synchrotron storage ring. The kinetic process has been studied by UV–visible spectroscopy as a function of the X-ray dose and compared to the nanoparticle growth induced in a bare mesoporous titania matrix. The graph...
Article
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Catalytic core–shell nanoparticles were obtained by coating an iron oxide core with a hybrid organic–inorganic silica shell using vinyl-triethoxy-silane and amino-propyl-triethoxy-silane. The amino group was further functionalised with arginine, used as catalytic moiety for the inactivation of organophosphate pesticides through hydrolysis. By explo...
Article
Graphene/silica nanocomposites in the form of highly porous aerogels are obtained for the first time by integrating a novel approach for the production of low defectivity graphene with a two-step route for the synthesis of silica-based monolith. Differently from the other synthetic methods, the use of co-gelation of dispersed phase and matrix follo...
Article
Carbon-dots (C-dots) nanocomposites represent a new frontier for highly efficient light-emitting materials with tunable colors in a wide range of the visible spectral region. We have developed a C-dots–ZnO system and the emission is finely controlled through material processing. The C-dots, besides being fluorophores, become a tool for modulating t...
Article
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Frontal polymerization was successfully used to synthesize copolymer hydrogels of poly(N-vinylcaprolactam-co-itaconic acid). All materials were characterized by response to stimuli (pH and/or temperature), depending on the itaconic acid content. Namely, relatively low amounts of this latter were found to be crucial for determining the degree of swe...
Article
Hard X-rays, deriving from a synchrotron light source, have been used as an effective tool for processing hybrid organic–inorganic films and thick coatings up to several micrometres. These coatings could be directly modified, in terms of composition and properties, by controlled exposure to X-rays. The physico-chemical properties of the coatings, s...
Chapter
In addition to UV light being applied for top-down processing, laser light, X-ray irradiation, γ-rays, and an electron beam can also induce structural modification and film densification upon exposure. Different photolithographic methods that are based on the direct interaction of the light source with sol-gel films have been developed. This chapte...
Article
Graphene sheets increase the Raman signal through a chemical enhancement mechanism which gives rise to graphene-mediated enhanced Raman scattering (GERS). The low enhancement factor and the surface available for analysis are, however, a limitation on the application of graphene-mediated enhanced Raman scattering (ERS). We have, therefore, developed...
Article
The present review is focused on a specific class of nanocomposites obtained through integration of graphene, or carbon-based nanomaterials (such as carbon nanodots), with mesoporous inorganic or hybrid materials, obtained via template assisted self-assembly. The task of integrating graphene and carbon nanodots with a self-assembly process is still...
Article
The in situ observation of a sol-to-gel transition in fast evaporating systems is a challenging task and the lack of a suitable experimental design, which includes the chemistry and the analytical method, has limited the observations. We synthesise an acidic sol, employing only tetraethylorthosilicate, SiCl4 as catalyst and deuterated water; the ab...
Article
Full-text available
A new type of mesostructured hybrid organic-inorganic film has been synthesised by evaporation-induced self-assembly using 3-glycidoxypropyltrimethoxysilane as precursor and a tri-block copolymer, Pluronic F127, as template. The chemistry has been tuned to form in the sol bridged polysilsesquioxanes that self-organize into ordered lamellar structur...
Article
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Ceria nanoparticles with controlled size have been studied as antioxidant agents for the in vitro protection of catecholaminergic cells (PC12) exposed to manganese, which is responsible for an occupational form of Parkinson-like disease. The nanoparticle internalization has been followed by Raman and confocal microscopy while the effect of nanoceri...
Article
A one-pot approach making use of a zinc oxide sol precursor and 14 carbon quantum dots, together with a partially fluorinated block copolymer as 15 templating agent, has been used to synthesize a porous matrix characterized by 16 interesting energy transfer properties. The choice of the fluorinated surfactant for 17 inducing the porosity into the i...
Article
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An innovative approach towards the physico-chemical tailoring of zinc oxide thin films is reported. The films have been deposited by liquid phase using the sol-gel method and then exposed to hard X-rays, provided by a synchrotron storage ring, for lithography. The use of surfactant and chelating agents in the sol allows easy-to-pattern films made b...
Article
The use of ZnO particles as efficient agents for seeding, growing, and precisely positioning metal−organic frameworks (MOFs) is described. Ceramic seeds have been successfully used for the preparation of Zn-based MOFs with a number of different carboxylic acids: terephthalic acid, 2-aminoterephthalic acid, 1,3,5-benzenetricarboxylic acid, 2,6-napht...
Article
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We have addressed an X-ray fluorescence (XRF) and X-ray diffraction (XRD) on a collection of thirteen fossil bone belonging to the Molı´ del Baro´ 1 paleontological site located near Sant Roma` d’Abella (Isona i Conca Della` Municipality, Lleida Province, Spain, dated to about 66.5 Ma, to investigate the fossilization occurred in this site in terms...