Eleonora PONTICORVO - Academia.edu (original) (raw)

Papers by Eleonora PONTICORVO

Mesoporous TiO 2 was prepared, inside "Taurasi" grape skins. The peel impregnation was followed b... more Mesoporous TiO 2 was prepared, inside "Taurasi" grape skins. The peel impregnation was followed by magnetic resonance imaging, to monitor the transport process in the natural template and the interaction of the solute with the templating structure. Moreover, the prepared mesoporous structure was used to support ultra-small platinum nanoparticles (USNPs), allowing high dispersion and maximizing active metals utilization. USNPs characterization was performed by means of high-resolution analytical transmission electron microscopy, CO-Diffuse Reflectance Infrared Fourier Transform spectroscopy, and X-ray photoelectron spectroscopy. Low Pt loaded TiO 2 was then tested in methanol oxidation reactions, showing an excellent behavior: negligible onset potentials (0.06 V) and very high If/Ib ratio (3.85). The results obtained in this work evidence the outstanding performances of the synthesized nano-electrocatalysts.

A controllable composition and morphology AuAg/ZnO catalyst, prepared by an easily scalable metho... more A controllable composition and morphology AuAg/ZnO catalyst, prepared by an easily scalable method, was, for the first time, explored for the electrocatalytic reduction of CO 2. It was found that the composition of the bimetallic alloy contributes to the overall CO 2 reduction performance. In particular, as also demonstrated by density functional theory calculations, CO production increases, decreasing the Au content in the catalyst alloy. The experimental investigation reveals that the products are H 2 and CO, which production rate increases in the presence of ZnO, up to a Faradic efficiency of 94.7 % at 0.4 V. On the other hand, controlling the oleic acid covering it is possible to modulate the surface properties allowing to obtain, at 0.6 V, H 2 /CO ratios equal to 1.1 and 1.9 for nanocatalysts thermally treated for 2 and 5 h, respectively.

A Tafel slope of 40 mV dec−1 and a very small overpotential were measured for our NiSMoS2G nanoca... more A Tafel slope of 40 mV dec−1 and a very small overpotential were measured for our NiSMoS2G nanocatalyst, prepared using a scalable approach, and consisting of NiS nanoparticles covered by a stabilizing coating of MoS2 nanosheets, on unsophisticated and easy to obtain physical exfoliated graphite. A careful study proves that it is possible to improve the Tafel slope and the overpotential through the optimization of amounts of the different components. The conductive nanocarbon network, the highly active to charge accumulation of NiS nanoparticles and the coupling with MoS2 nanosheets, exposing a large number of edges, result in a very high hydrogen production rate of 1.63 ml cm−2 h−1 at −0.12 V, measured by means of an on-line mass spectrometry analysis.

A novel electrocatalytic simple method, based on a Pt, Ir and Ru trimetallic nanoalloy (PtIrRu), ... more A novel electrocatalytic simple method, based on a Pt, Ir and Ru trimetallic nanoalloy (PtIrRu), was explored for the biodiesel production from Amalfi coast waste lemon seeds oil. The experiments were performed in a methanolic reaction mixture, in the absence of toxic co-solvents and active dissolved species, and operating at a moderate voltage. The transesterification reaction occurred with a low amount of nanocatalyst in a two-phase reaction mixture, where an emulsion of oil in the alcohol phase is formed under stirring. A systematic study, looking for combinations ensuring high biodiesel yields, was performed by varying the process parameters. The effects of the voltage, temperature, NaCl content, methanol/oil ratio, reaction time and water content on the methyl esters yield were explored and the products were analyzed. Although temperature does not significantly affect conversion, NaCl content and time were found crucial. Lemon seed oil conversion reached a value of 98.2% after 2 h at 15 V, 0.3 wt% of NaCl and 20°C, methanol/oil ratio 10:1, water content 2 wt%. Although a methyl esters yield reduction was observed in the presence of water, yields of 80% and 49.2% were still measured at 2 wt% and 4 wt% of water, respectively. The characteristics of the biodiesel produced were in agreement with the EN14214. The results of this paper constitute a proof of concept of the valorization in biodiesel of all lemon seed oils, also considering the large global scale citrus fruit consumption and processing, e.g. to produce fruit juices.

The direct conversion of methane is still a challenge. Here, an enhanced catalyst for direct and ... more The direct conversion of methane is still a challenge. Here, an enhanced catalyst for direct and selective oxidation of methane at low temperature was prepared by exploiting Rh single atoms, dispersed in a mixed oxides nanocomposite (based on NiO and V 2 O 5). We found that the prepared nanocatalyst can catalyze the selective oxidation of CH 4 efficiently to methanol. The maximum methanol production was 5.2 μmol/hcm 2 (0.65 mol h −1 g −1) with a current efficiency of 91 %. A negligible production of CO 2 (current efficiency of 6%) was the only other product. The methanol molar fraction kept stable for at least 500 min, at 100 mA, and T = 100°C. The comparative analysis with the literature results highlights the high efficiency of our catalyst in selectively promoting methanol production with high yields and stability, providing a novel pathway for the production of efficient catalysts based on the exploitation of single-atoms dispersed on useful surfaces.

MoS2/ZnO nanoparticles (NPs) were synthesized by a one step, highly promising synthesis approach,... more MoS2/ZnO nanoparticles (NPs) were synthesized by a one step, highly promising synthesis approach, to be tested for the effective removal of hydrogen sulfide from drilling mud. The syntheses were performed by thermolysis of ammonium thiomolybdates (NH4)2MoS4 and zinc(II)acetylacetonate in a three necked flask under a flow of nitrogen. Zinc oxide NPs alone were also prepared. The samples were characterized by Raman Spectroscopy, Transmission (TEM-EDS) Electron Microscopy and X-ray diffraction (XRD). The synthesized NPs were used to remove hydrogen sulfide from water based drilling fluid. The efficiency of these NPs in the removal of hydrogen sulfide from drilling mud was evaluated and compared with that of ZnO NPs alone. The obtained results show that an amount of 3 g of MoS2/ZnO NPs is able to remove 100% of H2S (800 ppm) from water based drilling mud in just few minutes. On the other hand, 60 minutes are required in the case of 3 g of ZnO NPs alone.

Chemical engineering transactions, 2019

Flower-like AuPtPd-Fe3O4 new nanohybrid prepared through a scalable synthetic approach was tested... more Flower-like AuPtPd-Fe3O4 new nanohybrid prepared through a scalable synthetic approach was tested for the effective and simultaneous removal of Humic Acids and Cr (VI). Field emission scanning electron microscopy (FESEM) equipped with an energy dispersive X-ray (EDX) probe, X-ray diffractometer (XRD) and thermogravimetric analysis (TG-DTG) were used for characterization. The nanocatalyst, at the end of the preparation process, results dispersible in water. Calibration equations were plotted for the removal evaluation of Cr(VI) and Humic Acids in water samples. Electrochemical tests were carried out at pH 3.0 and 30 mA. Humic Acids were highly mineralized with TOC removal efficiency of 95%. In 3 h, 99 % of total Cr was removed.

Chemical engineering transactions, 2019

Hyper-cross-linked (HCL) styrene-based resins filled with graphite nanoplatelets (GNP) at two dif... more Hyper-cross-linked (HCL) styrene-based resins filled with graphite nanoplatelets (GNP) at two different GNP concentrations were synthesized by means of a facile and efficient modified Davankov procedure. Firstly, the synthesized samples were broadly characterized by means of transmission electron microscopy (TEM) and thermogravimetric analysis (TG-DTG), and their BET surface areas were also evaluated. Afterwards, capacitance performance of the synthesized electrode materials was investigated by cyclic voltammetry in a 0.5 M H2SO4 solution at different scan rates, also exploring the effects of GNPs concentration. The synthesized materials showed high specific capacitances (Csp) of 52.1 F/g and 60.4 F/g, values obtained with a concentration of the GNP fillers equal to 7.5 wt% and 10 %wt respectively. Moreover, the synthesized nanocomposites exhibited a high capacitance retention up to 97 % over 10000 cycles, thus confirming their excellent performances as robust EDLC electrode materials.

Mercaptans are molecules with high volatility, responsible for unpleasant odours. They have a ver... more Mercaptans are molecules with high volatility, responsible for unpleasant odours. They have a very low olfactory threshold, e.g. for CH3SH of ~0.39 ppbv. In this paper, copper oxide nanoparticles supported on graphene were synthesized for the removal of low-concentration CH3SH (5 ppm). That results show that the humidity has a significant impact on the elimination of odors. The adsorption ability grows at increasing conditions of relative humidity (RH). The adsorption capacity at RH = 80 % is 2 or 5 times higher than that shown at RH = 4 %. The surface of CuO nanoparticles is highly responsible for the formation of hydrated complexes that are effective in the acquisition of CH3SH.

Chemical engineering transactions, 2019

Ruthenium/osmium based controlled size nanoparticles (NPs), supported on graphene, have been prep... more Ruthenium/osmium based controlled size nanoparticles (NPs), supported on graphene, have been prepared by a simple synthetic strategy consisting in the thermolysis of a suitable precursor in organic solvent under a low oxygen enriched atmosphere. An excellent combination of a low Tafel slope of 28 mV/dec with a negligible overpotential was measured for the prepared nanocomposite (RuOs_G), due to metal oxides resulting in electron rich Ru and Os islands. The nanocatalyst shows an activity higher than that of common Pt. Additionally, the paper proves that it is possible to use the synthesized nanocatalyst to catalyse directly seawater splitting. RuOs_G resulted very stable and active in complex solutions during electrolysis under high current density.

Chemical engineering transactions, 2021

This work describes the preparation of an Al2O3 electrode material for a performing and stable su... more This work describes the preparation of an Al2O3 electrode material for a performing and stable supercapacitor. The electrode was prepared by a DC thermal plasma plant installed at ENEA Research Centre of Portici. The structures and morphologies of samples were characterized by SEM, XRD, TG, and FT-IR. Al2O3 electrode electrochemical characteristics were performed in a sulphuric acid solution electrolyte. Cyclic Voltammetry (CV) technique was carried out. The results show that Al2O3 exhibits a good specific capacitance. Furthermore, after 10000 cycles, 98% of the initial capacitance was maintained.

Chemical engineering transactions, 2021

A facile and cost-effective procedure to synthesize honeycomb-like porous TiO2, which exhibits sp... more A facile and cost-effective procedure to synthesize honeycomb-like porous TiO2, which exhibits specific capacitance of 0.2 F/cm2 at 20 mV/s, was proposed. Scanning Electron Microscopy (SEM), thermogravimetric analysis (TG), UV/Vis, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD) were employed for characterization. The electrochemical performances of the electrode were investigated in acidic solution.

Chemical engineering transactions, 2020

Here we report the performance in ammonia detection of polystyrene-based hyper-cross-linked polym... more Here we report the performance in ammonia detection of polystyrene-based hyper-cross-linked polymer (HCLP) synthesized with a new synthetic route. The resin loaded with PtRu nano-alloy covered by MoS2 nanosheets, prepared according to a “wet chemistry” approach, was broadly characterized: TEM images and XRD spectra showed the formation of nanoparticles with a few nanometers size partially covered by MoS2 layers. The sample was tested as an electrochemical sensor for the detection of small traces of NH3 in aqueous solutions with a limit of detection (LOD) of 4.5 µM. The sensor was tested also in simulated wastewater coming from the fertilizer industry, showing proper operation and excellent selectivity.

Energy generation from renewable sources such as solar and wind energy is more and more required,... more Energy generation from renewable sources such as solar and wind energy is more and more required, to decrease greenhouse gas emissions and fossil fuels consumption. Considering the intermittence and variability of renewable energy sources large-scale and highly efficient energy storage systems, able to quickly respond to large and rapid fluctuations, are crucial to enhance the renewable energy sources exploitation. For the practical application of large-scale energy storage, novel technologies, having major advantages of both electrochemical capacitors and batteries, are required. Energy storage systems common electrodes include carbon based materials (e.g. activated carbon, carbon nanotubes, graphene, etc.), transition-metal and metal oxides, conducting polymers and composites of these materials [1]. Thanks to their high conductivity, electrochemical stability and ability to electrons transport, noble metals have attracted increasing attention in the field of electrode materials [2...

Chemical engineering transactions, 2020

Here we report the performance in 5-Hydroxymethylfurfural (HMF) reduction of Ag_graphene-based el... more Here we report the performance in 5-Hydroxymethylfurfural (HMF) reduction of Ag_graphene-based electrode. The prepared nanocomposite, synthesized according to a “wet chemistry” approach, was broadly characterized: SEM images and XRD spectrum indicate the formation of nanoparticles dispersed on few-layers graphene. A multimodal pore distribution, indicating a network of larger and smaller pores enabling electrode wettability and exposing surface nanoparticles, was evaluated.The sample was tested for the oxidation of HMF in a sulfate buffer solution. A very high overpotential gap between hydrogen production and HMF conversion was demonstrated. High efficiency (FE = 65.1%) and selectivity (70.2%), with little amount of bis(hydroxymethyl)furan by-product (FE < 6%), were demonstrated.

European Journal of Inorganic Chemistry, 2020

Few layer graphene (FLG)/Fe3O4 nanohybrid has been successfully synthesized by an one-step chemic... more Few layer graphene (FLG)/Fe3O4 nanohybrid has been successfully synthesized by an one-step chemical strategy, consisting in the thermolysis of a suitable magnetite precursor in organic solvent in the presence of surfactants and FLG. This way provides experimental easiness and potential low-cost production. Raman spectroscopy, Transmission electron microscopy – Energy dispersive X-ray spectroscopy (TEM-EDS), thermogravimetric analysis coupled with mass spectromery (TG-DTG-MS) and X-ray diffraction (XRD) were employed for characterization. The nanoparticles with a size of 5 nm, are monodispersed on FLG. The FLGFe3O4 hybrid supercapacitor has good electrochemical capacitance performance within potential range from 0 to 1.0 V. The resulting composite exhibited high specific capacitances of 227 F/g and good cyclability in a three-electrode electrochemical cell. The excellent electrochemical performances can be attributed to the high conductivity of FLG as well as to the uniform nano-size...

Mesoporous TiO 2 was prepared, inside "Taurasi" grape skins. The peel impregnation was followed b... more Mesoporous TiO 2 was prepared, inside "Taurasi" grape skins. The peel impregnation was followed by magnetic resonance imaging, to monitor the transport process in the natural template and the interaction of the solute with the templating structure. Moreover, the prepared mesoporous structure was used to support ultra-small platinum nanoparticles (USNPs), allowing high dispersion and maximizing active metals utilization. USNPs characterization was performed by means of high-resolution analytical transmission electron microscopy, CO-Diffuse Reflectance Infrared Fourier Transform spectroscopy, and X-ray photoelectron spectroscopy. Low Pt loaded TiO 2 was then tested in methanol oxidation reactions, showing an excellent behavior: negligible onset potentials (0.06 V) and very high If/Ib ratio (3.85). The results obtained in this work evidence the outstanding performances of the synthesized nano-electrocatalysts.

A controllable composition and morphology AuAg/ZnO catalyst, prepared by an easily scalable metho... more A controllable composition and morphology AuAg/ZnO catalyst, prepared by an easily scalable method, was, for the first time, explored for the electrocatalytic reduction of CO 2. It was found that the composition of the bimetallic alloy contributes to the overall CO 2 reduction performance. In particular, as also demonstrated by density functional theory calculations, CO production increases, decreasing the Au content in the catalyst alloy. The experimental investigation reveals that the products are H 2 and CO, which production rate increases in the presence of ZnO, up to a Faradic efficiency of 94.7 % at 0.4 V. On the other hand, controlling the oleic acid covering it is possible to modulate the surface properties allowing to obtain, at 0.6 V, H 2 /CO ratios equal to 1.1 and 1.9 for nanocatalysts thermally treated for 2 and 5 h, respectively.

A Tafel slope of 40 mV dec−1 and a very small overpotential were measured for our NiSMoS2G nanoca... more A Tafel slope of 40 mV dec−1 and a very small overpotential were measured for our NiSMoS2G nanocatalyst, prepared using a scalable approach, and consisting of NiS nanoparticles covered by a stabilizing coating of MoS2 nanosheets, on unsophisticated and easy to obtain physical exfoliated graphite. A careful study proves that it is possible to improve the Tafel slope and the overpotential through the optimization of amounts of the different components. The conductive nanocarbon network, the highly active to charge accumulation of NiS nanoparticles and the coupling with MoS2 nanosheets, exposing a large number of edges, result in a very high hydrogen production rate of 1.63 ml cm−2 h−1 at −0.12 V, measured by means of an on-line mass spectrometry analysis.

A novel electrocatalytic simple method, based on a Pt, Ir and Ru trimetallic nanoalloy (PtIrRu), ... more A novel electrocatalytic simple method, based on a Pt, Ir and Ru trimetallic nanoalloy (PtIrRu), was explored for the biodiesel production from Amalfi coast waste lemon seeds oil. The experiments were performed in a methanolic reaction mixture, in the absence of toxic co-solvents and active dissolved species, and operating at a moderate voltage. The transesterification reaction occurred with a low amount of nanocatalyst in a two-phase reaction mixture, where an emulsion of oil in the alcohol phase is formed under stirring. A systematic study, looking for combinations ensuring high biodiesel yields, was performed by varying the process parameters. The effects of the voltage, temperature, NaCl content, methanol/oil ratio, reaction time and water content on the methyl esters yield were explored and the products were analyzed. Although temperature does not significantly affect conversion, NaCl content and time were found crucial. Lemon seed oil conversion reached a value of 98.2% after 2 h at 15 V, 0.3 wt% of NaCl and 20°C, methanol/oil ratio 10:1, water content 2 wt%. Although a methyl esters yield reduction was observed in the presence of water, yields of 80% and 49.2% were still measured at 2 wt% and 4 wt% of water, respectively. The characteristics of the biodiesel produced were in agreement with the EN14214. The results of this paper constitute a proof of concept of the valorization in biodiesel of all lemon seed oils, also considering the large global scale citrus fruit consumption and processing, e.g. to produce fruit juices.

The direct conversion of methane is still a challenge. Here, an enhanced catalyst for direct and ... more The direct conversion of methane is still a challenge. Here, an enhanced catalyst for direct and selective oxidation of methane at low temperature was prepared by exploiting Rh single atoms, dispersed in a mixed oxides nanocomposite (based on NiO and V 2 O 5). We found that the prepared nanocatalyst can catalyze the selective oxidation of CH 4 efficiently to methanol. The maximum methanol production was 5.2 μmol/hcm 2 (0.65 mol h −1 g −1) with a current efficiency of 91 %. A negligible production of CO 2 (current efficiency of 6%) was the only other product. The methanol molar fraction kept stable for at least 500 min, at 100 mA, and T = 100°C. The comparative analysis with the literature results highlights the high efficiency of our catalyst in selectively promoting methanol production with high yields and stability, providing a novel pathway for the production of efficient catalysts based on the exploitation of single-atoms dispersed on useful surfaces.

MoS2/ZnO nanoparticles (NPs) were synthesized by a one step, highly promising synthesis approach,... more MoS2/ZnO nanoparticles (NPs) were synthesized by a one step, highly promising synthesis approach, to be tested for the effective removal of hydrogen sulfide from drilling mud. The syntheses were performed by thermolysis of ammonium thiomolybdates (NH4)2MoS4 and zinc(II)acetylacetonate in a three necked flask under a flow of nitrogen. Zinc oxide NPs alone were also prepared. The samples were characterized by Raman Spectroscopy, Transmission (TEM-EDS) Electron Microscopy and X-ray diffraction (XRD). The synthesized NPs were used to remove hydrogen sulfide from water based drilling fluid. The efficiency of these NPs in the removal of hydrogen sulfide from drilling mud was evaluated and compared with that of ZnO NPs alone. The obtained results show that an amount of 3 g of MoS2/ZnO NPs is able to remove 100% of H2S (800 ppm) from water based drilling mud in just few minutes. On the other hand, 60 minutes are required in the case of 3 g of ZnO NPs alone.

Chemical engineering transactions, 2019

Flower-like AuPtPd-Fe3O4 new nanohybrid prepared through a scalable synthetic approach was tested... more Flower-like AuPtPd-Fe3O4 new nanohybrid prepared through a scalable synthetic approach was tested for the effective and simultaneous removal of Humic Acids and Cr (VI). Field emission scanning electron microscopy (FESEM) equipped with an energy dispersive X-ray (EDX) probe, X-ray diffractometer (XRD) and thermogravimetric analysis (TG-DTG) were used for characterization. The nanocatalyst, at the end of the preparation process, results dispersible in water. Calibration equations were plotted for the removal evaluation of Cr(VI) and Humic Acids in water samples. Electrochemical tests were carried out at pH 3.0 and 30 mA. Humic Acids were highly mineralized with TOC removal efficiency of 95%. In 3 h, 99 % of total Cr was removed.

Chemical engineering transactions, 2019

Hyper-cross-linked (HCL) styrene-based resins filled with graphite nanoplatelets (GNP) at two dif... more Hyper-cross-linked (HCL) styrene-based resins filled with graphite nanoplatelets (GNP) at two different GNP concentrations were synthesized by means of a facile and efficient modified Davankov procedure. Firstly, the synthesized samples were broadly characterized by means of transmission electron microscopy (TEM) and thermogravimetric analysis (TG-DTG), and their BET surface areas were also evaluated. Afterwards, capacitance performance of the synthesized electrode materials was investigated by cyclic voltammetry in a 0.5 M H2SO4 solution at different scan rates, also exploring the effects of GNPs concentration. The synthesized materials showed high specific capacitances (Csp) of 52.1 F/g and 60.4 F/g, values obtained with a concentration of the GNP fillers equal to 7.5 wt% and 10 %wt respectively. Moreover, the synthesized nanocomposites exhibited a high capacitance retention up to 97 % over 10000 cycles, thus confirming their excellent performances as robust EDLC electrode materials.

Mercaptans are molecules with high volatility, responsible for unpleasant odours. They have a ver... more Mercaptans are molecules with high volatility, responsible for unpleasant odours. They have a very low olfactory threshold, e.g. for CH3SH of ~0.39 ppbv. In this paper, copper oxide nanoparticles supported on graphene were synthesized for the removal of low-concentration CH3SH (5 ppm). That results show that the humidity has a significant impact on the elimination of odors. The adsorption ability grows at increasing conditions of relative humidity (RH). The adsorption capacity at RH = 80 % is 2 or 5 times higher than that shown at RH = 4 %. The surface of CuO nanoparticles is highly responsible for the formation of hydrated complexes that are effective in the acquisition of CH3SH.

Chemical engineering transactions, 2019

Ruthenium/osmium based controlled size nanoparticles (NPs), supported on graphene, have been prep... more Ruthenium/osmium based controlled size nanoparticles (NPs), supported on graphene, have been prepared by a simple synthetic strategy consisting in the thermolysis of a suitable precursor in organic solvent under a low oxygen enriched atmosphere. An excellent combination of a low Tafel slope of 28 mV/dec with a negligible overpotential was measured for the prepared nanocomposite (RuOs_G), due to metal oxides resulting in electron rich Ru and Os islands. The nanocatalyst shows an activity higher than that of common Pt. Additionally, the paper proves that it is possible to use the synthesized nanocatalyst to catalyse directly seawater splitting. RuOs_G resulted very stable and active in complex solutions during electrolysis under high current density.

Chemical engineering transactions, 2021

This work describes the preparation of an Al2O3 electrode material for a performing and stable su... more This work describes the preparation of an Al2O3 electrode material for a performing and stable supercapacitor. The electrode was prepared by a DC thermal plasma plant installed at ENEA Research Centre of Portici. The structures and morphologies of samples were characterized by SEM, XRD, TG, and FT-IR. Al2O3 electrode electrochemical characteristics were performed in a sulphuric acid solution electrolyte. Cyclic Voltammetry (CV) technique was carried out. The results show that Al2O3 exhibits a good specific capacitance. Furthermore, after 10000 cycles, 98% of the initial capacitance was maintained.

Chemical engineering transactions, 2021

A facile and cost-effective procedure to synthesize honeycomb-like porous TiO2, which exhibits sp... more A facile and cost-effective procedure to synthesize honeycomb-like porous TiO2, which exhibits specific capacitance of 0.2 F/cm2 at 20 mV/s, was proposed. Scanning Electron Microscopy (SEM), thermogravimetric analysis (TG), UV/Vis, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD) were employed for characterization. The electrochemical performances of the electrode were investigated in acidic solution.

Chemical engineering transactions, 2020

Here we report the performance in ammonia detection of polystyrene-based hyper-cross-linked polym... more Here we report the performance in ammonia detection of polystyrene-based hyper-cross-linked polymer (HCLP) synthesized with a new synthetic route. The resin loaded with PtRu nano-alloy covered by MoS2 nanosheets, prepared according to a “wet chemistry” approach, was broadly characterized: TEM images and XRD spectra showed the formation of nanoparticles with a few nanometers size partially covered by MoS2 layers. The sample was tested as an electrochemical sensor for the detection of small traces of NH3 in aqueous solutions with a limit of detection (LOD) of 4.5 µM. The sensor was tested also in simulated wastewater coming from the fertilizer industry, showing proper operation and excellent selectivity.

Energy generation from renewable sources such as solar and wind energy is more and more required,... more Energy generation from renewable sources such as solar and wind energy is more and more required, to decrease greenhouse gas emissions and fossil fuels consumption. Considering the intermittence and variability of renewable energy sources large-scale and highly efficient energy storage systems, able to quickly respond to large and rapid fluctuations, are crucial to enhance the renewable energy sources exploitation. For the practical application of large-scale energy storage, novel technologies, having major advantages of both electrochemical capacitors and batteries, are required. Energy storage systems common electrodes include carbon based materials (e.g. activated carbon, carbon nanotubes, graphene, etc.), transition-metal and metal oxides, conducting polymers and composites of these materials [1]. Thanks to their high conductivity, electrochemical stability and ability to electrons transport, noble metals have attracted increasing attention in the field of electrode materials [2...

Chemical engineering transactions, 2020

Here we report the performance in 5-Hydroxymethylfurfural (HMF) reduction of Ag_graphene-based el... more Here we report the performance in 5-Hydroxymethylfurfural (HMF) reduction of Ag_graphene-based electrode. The prepared nanocomposite, synthesized according to a “wet chemistry” approach, was broadly characterized: SEM images and XRD spectrum indicate the formation of nanoparticles dispersed on few-layers graphene. A multimodal pore distribution, indicating a network of larger and smaller pores enabling electrode wettability and exposing surface nanoparticles, was evaluated.The sample was tested for the oxidation of HMF in a sulfate buffer solution. A very high overpotential gap between hydrogen production and HMF conversion was demonstrated. High efficiency (FE = 65.1%) and selectivity (70.2%), with little amount of bis(hydroxymethyl)furan by-product (FE < 6%), were demonstrated.

European Journal of Inorganic Chemistry, 2020

Few layer graphene (FLG)/Fe3O4 nanohybrid has been successfully synthesized by an one-step chemic... more Few layer graphene (FLG)/Fe3O4 nanohybrid has been successfully synthesized by an one-step chemical strategy, consisting in the thermolysis of a suitable magnetite precursor in organic solvent in the presence of surfactants and FLG. This way provides experimental easiness and potential low-cost production. Raman spectroscopy, Transmission electron microscopy – Energy dispersive X-ray spectroscopy (TEM-EDS), thermogravimetric analysis coupled with mass spectromery (TG-DTG-MS) and X-ray diffraction (XRD) were employed for characterization. The nanoparticles with a size of 5 nm, are monodispersed on FLG. The FLGFe3O4 hybrid supercapacitor has good electrochemical capacitance performance within potential range from 0 to 1.0 V. The resulting composite exhibited high specific capacitances of 227 F/g and good cyclability in a three-electrode electrochemical cell. The excellent electrochemical performances can be attributed to the high conductivity of FLG as well as to the uniform nano-size...