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Catalytic electroreduction of carbon dioxide represents a promising technology both to reduce CO2 emissions and to store electrical energy from discontinuous sources. In this work, electrochemical deposition of copper on to a gas-diffusion support was tested as a scalable and versatile nanosynthesis technique for the production of catalytic electrodes for CO2 electroreduction. The effect of deposition current density and additives (DAT, DTAB, PEG) on the catalysts’ structure was evaluated. The selectivity of the synthesized catalysts towards the production of CO was evaluated by analyzing the gaseous products obtained using the catalysts as cathodes in electroreduction tests. Catalyst morphology was deeply influenced by the deposition additives. Copper nanospheres, hemispherical microaggregates of nanowires, and shapeless structures were electrodeposited in the presence of dodecyltrimethylammonium bromide (DTAB), 3,5-diamino-1,2,4-triazole (DAT) and polyethylene glycol (PEG), respectively. The effect of the deposition current density on catalyst morphology was also observed and it was found to be additive-specific. DTAB nanostructured electrodes showed the highest selectivity towards CO production, probably attributable to a higher specific surface area. EDX and XPS analysis disclosed the presence of residual DAT and DTAB uniformly distributed onto the catalysts structure. No significant effects of electrodeposition current density and Cu(I)/Cu(II) ratio on the selectivity towards CO were found. In particular, DTAB and DAT electrodes yielded comparable selectivity, although they were characterized by the highest and lowest Cu(I)/Cu(II) ratio, respectively.
Gianluca Zanellato; Pier Giorgio Schiavi; Robertino Zanoni; Antonio Rubino; Pietro Altimari; Francesca Pagnanelli. Electrodeposited Copper Nanocatalysts for CO2 Electroreduction: Effect of Electrodeposition Conditions on Catalysts’ Morphology and Selectivity. Energies 2021, 14, 5012 .
AMA StyleGianluca Zanellato, Pier Giorgio Schiavi, Robertino Zanoni, Antonio Rubino, Pietro Altimari, Francesca Pagnanelli. Electrodeposited Copper Nanocatalysts for CO2 Electroreduction: Effect of Electrodeposition Conditions on Catalysts’ Morphology and Selectivity. Energies. 2021; 14 (16):5012.
Chicago/Turabian StyleGianluca Zanellato; Pier Giorgio Schiavi; Robertino Zanoni; Antonio Rubino; Pietro Altimari; Francesca Pagnanelli. 2021. "Electrodeposited Copper Nanocatalysts for CO2 Electroreduction: Effect of Electrodeposition Conditions on Catalysts’ Morphology and Selectivity." Energies 14, no. 16: 5012.
The increase in the annual flux of the end-of-life photovoltaic panels (EoL-PVPs) imposed the development of effective recycling strategies to reach EU regulation targets (i.e. 80% recycling; 85% recovery, starting from August 2018). The recycling targets in a PVP are generally glass, photovoltaic cell and metals, while no scientific paper or patent addressed polymeric fractions recycling and recovery, i.e. encapsulant polymer (EVA) and backsheet (Tedlar), starting from preliminarily milled EoL-PVPs. In the present study an optimization following the solvent treatment operation of the basic Photolife process (demonstrated at pilot scale), was proposed (lab scale) and validated (micropilot scale), focusing on polymers separation and metals recovery. The optimization was performed by testing 4 different processes. Specifically, the selectivity of the filtration operation (subsequent the solvent treatment) on polymers separation grade was evaluated, demonstrating that Tedlar can be effectively separated from EVA residues. Moreover, in comparison to the basic Photolife, a further operation was introduced treating thermally the EVA residues (containing the PV cell). The metal extraction yields highlighted the effectiveness of that strategy in comparison with direct extraction from the uncombusted EVA residues. Processing 100 Kg of crushed material, 0.03 Kg of Ag, 45.5 Kg of high value glass, 10 Kg of Al scraps and 1.2 Kg of metallic filaments can be recovered. Thanks to the optimization the recycling rate of the implemented process grew up to 82% (75% during demonstration of the basic Photolife process), while the recovery was estimated at 94%. Remarkably, these rates get over with EU Directive.
Antonio Rubino; Pier Giorgio Schiavi; Pietro Altimari; Francesca Pagnanelli. Valorization of polymeric fractions and metals from end of life photovoltaic panels. Waste Management 2021, 122, 89 -99.
AMA StyleAntonio Rubino, Pier Giorgio Schiavi, Pietro Altimari, Francesca Pagnanelli. Valorization of polymeric fractions and metals from end of life photovoltaic panels. Waste Management. 2021; 122 ():89-99.
Chicago/Turabian StyleAntonio Rubino; Pier Giorgio Schiavi; Pietro Altimari; Francesca Pagnanelli. 2021. "Valorization of polymeric fractions and metals from end of life photovoltaic panels." Waste Management 122, no. : 89-99.
Photovoltaic panels were included in EU Directive as WEEE (Wastes of Electric and Electronic Equipment) requiring the implementation of dedicated collection schemes and end-of-life treatment ensuring targets in terms of recycling rate (80%) and recovery rate (85%). Photovoltaic panels are mainly made up of high-quality solar glass (70–90%), but also metals are present in the frames (Al), the cell (Si), and metallic contacts (Cu and Ag). According to the panel composition, about $72 per 100 kg of panels can be recovered by entirely recycling the panel metal content. The PhotoLife process for the treatment of end-of-life photovoltaic panels was demonstrated at pilot scale to recycle high value glass, Al and Cu scraps. A process upgrade is here reported allowing for polymer separation and Ag and Si recycling. By this advanced PhotoLife process, 82% recycling rate, 94% recovery rate, and 75% recoverable value were attained. Simulations demonstrated the economic feasibility of the process at processing capacity of 30,000 metric ton/y of end-of-life photovoltaic panels.
Antonio Rubino; Giuseppe Granata; Emanuela Moscardini; Ludovica Baldassari; Pietro Altimari; Luigi Toro; Francesca Pagnanelli. Development and Techno-Economic Analysis of an Advanced Recycling Process for Photovoltaic Panels Enabling Polymer Separation and Recovery of Ag and Si. Energies 2020, 13, 6690 .
AMA StyleAntonio Rubino, Giuseppe Granata, Emanuela Moscardini, Ludovica Baldassari, Pietro Altimari, Luigi Toro, Francesca Pagnanelli. Development and Techno-Economic Analysis of an Advanced Recycling Process for Photovoltaic Panels Enabling Polymer Separation and Recovery of Ag and Si. Energies. 2020; 13 (24):6690.
Chicago/Turabian StyleAntonio Rubino; Giuseppe Granata; Emanuela Moscardini; Ludovica Baldassari; Pietro Altimari; Luigi Toro; Francesca Pagnanelli. 2020. "Development and Techno-Economic Analysis of an Advanced Recycling Process for Photovoltaic Panels Enabling Polymer Separation and Recovery of Ag and Si." Energies 13, no. 24: 6690.
Electrochemical nucleation and growth of cobalt nanoparticles on aluminium was investigated by potentiostatic electrodeposition from cobalt sulphate solutions buffered with boric acid. At sufficiently low overpotential, the experimental current transients could be fairly reproduced by a mathematical model describing nucleation and growth under mixed kinetic-diffusion control, yielding an estimated number of particles per surface area in agreement with the SEM analysis of the deposits. However, the model gave estimates for the charge-transfer kinetic constant several orders of magnitude lower as compared to the Tafel analysis of cobalt electrodeposition on a previously electrodeposited cobalt film. This deviation can be explained by the inhibition of the direct attachment of metal ions, which can be induced by the adsorption of hydrogen onto cobalt particles and/or the formation of stable nanocluster aggregates. The implemented model failed to reproduce the current transients generated at larger overpotential values. A revision of the implemented mathematical model overcoming this limitation is proposed.
Pietro Altimari; Pier Giorgio Schiavi; Antonio Rubino; Francesca Pagnanelli. Electrodeposition of cobalt nanoparticles: An analysis of the mechanisms behind the deviation from three-dimensional diffusion-control. Journal of Electroanalytical Chemistry 2019, 851, 113413 .
AMA StylePietro Altimari, Pier Giorgio Schiavi, Antonio Rubino, Francesca Pagnanelli. Electrodeposition of cobalt nanoparticles: An analysis of the mechanisms behind the deviation from three-dimensional diffusion-control. Journal of Electroanalytical Chemistry. 2019; 851 ():113413.
Chicago/Turabian StylePietro Altimari; Pier Giorgio Schiavi; Antonio Rubino; Francesca Pagnanelli. 2019. "Electrodeposition of cobalt nanoparticles: An analysis of the mechanisms behind the deviation from three-dimensional diffusion-control." Journal of Electroanalytical Chemistry 851, no. : 113413.
In this work, an electrochemical approach to synthesize Metal-MetalOxide/Hydroxide core-shell nanowires electrodes (NWE) is illustrated. NWE electrodes were obtained by electrodeposition of a targeted metal into the nanopores of nanoporous alumina templates generated by one-step anodization of aluminum. Following metal electrodeposition, the alumina template was selectively etched to obtain an array of free-standing metal nanowires. The imposed electrodeposition conditions allowed directly attaining a core-shell nanostructure, with a metal core covered by a thin metal oxide/hydroxide film. NWE electrodes produced by the proposed synthesis route were tested for the application as electrodes in lithium batteries and supercapacitors. To this purpose, an array of cobalt nanowires (CoNWs) supported by a nanostructured copper current collector was produced by sequential electrodeposition of cobalt and copper, and it was employed as anode in a lithium battery, while a NWE based on Ni-NiO/OH2 (NiNWs) was obtained by nickel electrodeposition and tested as electrode in a supercapacitor. A thorough analysis and characterization of the produced electrodes were performed. The experiments with the lithium cell evidenced the positive effect of metallic core on stability, while the electrochemical characterization of the supercapacitor showed the presence of both NiO and NiOH2 leading, when cycled, to a capacity close to the best literature value.
Pier Giorgio Schiavi; Luca Farina; Antonio Rubino; Pietro Altimari; Maria Assunta Navarra; Robertino Zanoni; Stefania Panero; Francesca Pagnanelli. Electrochemical synthesis of nanowires electrodes and their application in energy storage devices. 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) 2019, 2145, 020012 .
AMA StylePier Giorgio Schiavi, Luca Farina, Antonio Rubino, Pietro Altimari, Maria Assunta Navarra, Robertino Zanoni, Stefania Panero, Francesca Pagnanelli. Electrochemical synthesis of nanowires electrodes and their application in energy storage devices. 15th International Conference on Concentrator Photovoltaic Systems (CPV-15). 2019; 2145 (1):020012.
Chicago/Turabian StylePier Giorgio Schiavi; Luca Farina; Antonio Rubino; Pietro Altimari; Maria Assunta Navarra; Robertino Zanoni; Stefania Panero; Francesca Pagnanelli. 2019. "Electrochemical synthesis of nanowires electrodes and their application in energy storage devices." 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) 2145, no. 1: 020012.
Energy from renewables (solar, photovoltaic, geothermal), is a major challenge for researchers’ efforts in reason of the intermittent nature of these energy sources. Systems like photoelectrochemical (PEC) cells are promising devices that allow the direct conversion of solar energy into electric power and/or chemical fuels. The direct conversion of solar energy in fuels can be achieved using photocatalysts, based on semiconductors like TiO2. In this work TiO2 nanotubes were achieved through “one-step” anodization of titanium, a low cost and accurate method which allowed to control dimensions and morphology of the nanostructured Ti/TiO2 electrodes. Central limit for TiO2 photoconversion efficiency is its wide bandgap (i.e. ~3.2eV), which limits light absorption to the ultraviolet region (3–5% of the solar radiation). Composite Cu2O/TiO2 systems have attracted much attention: Cu2O is a promising semiconductor material (bandgap 2.0-2.6eV), suitable to absorb visible light. Traditionally, Cu2O deposition techniques include the impregnation of TiO2 with a copper salt and subsequent calcination, but offers little control on sizes, shape and deposit’s composition. In this work we developed an electrodeposition method in order to control Cu2O morphology and sizes in the composed Ti/TiO2/Cu2O electrodes.
Antonio Rubino; Pier Giorgio Schiavi; Pietro Altimari; Francesca Pagnanelli. Ti/TiO2/Cu2O electrodes for photocatalytic applications: Synthesis and characterization. 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) 2019, 2145, 020005 .
AMA StyleAntonio Rubino, Pier Giorgio Schiavi, Pietro Altimari, Francesca Pagnanelli. Ti/TiO2/Cu2O electrodes for photocatalytic applications: Synthesis and characterization. 15th International Conference on Concentrator Photovoltaic Systems (CPV-15). 2019; 2145 (1):020005.
Chicago/Turabian StyleAntonio Rubino; Pier Giorgio Schiavi; Pietro Altimari; Francesca Pagnanelli. 2019. "Ti/TiO2/Cu2O electrodes for photocatalytic applications: Synthesis and characterization." 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) 2145, no. 1: 020005.
A novel process is proposed to produce nanostructured batteries anodes from spent lithium-ion batteries. The electrodic powder recovered by the mechanical treatment of spent batteries was leached and the dissolved metals were precipitated as cobalt carbonates. Two different precipitation routes were separately tested producing cobalt carbonates with different Cu and Fe contents. Nanowire anodes were produced by electrodeposition into nanoporous alumina templates from the electrolytic baths prepared by dissolution of the precipitated carbonates. The electrochemical performances of the produced anodes were evaluated as compared to nanowire anodes produced with the same electrodeposition method but using a synthetic cobalt bath. The application of the carbonates produced by directly precipitating all the leached metals gave nanowires with capacity about halved as compared to the nanowires electrodeposited from the synthetic bath. Selectively removing Cu and Fe prior cobalt carbonate precipitation yielded, in contrast, nanowires with capacity initially larger and then gradually approaching that attained by the nanowire electrodeposited from the synthetic bath. A detailed analysis is presented describing the role of metallic impurities in determining the capacity of the produced nanowires. The impact of the illustrated results for the development of sustainable recycling processes of lithium-ion batteries is discussed.
Pier Giorgio Schiavi; Luca Farina; Robertino Zanoni; Pietro Altimari; Iulia Cojocariu; Antonio Rubino; Maria Assunta Navarra; Stefania Panero; Francesca Pagnanelli. Electrochemical synthesis of nanowire anodes from spent lithium ion batteries. Electrochimica Acta 2019, 319, 481 -489.
AMA StylePier Giorgio Schiavi, Luca Farina, Robertino Zanoni, Pietro Altimari, Iulia Cojocariu, Antonio Rubino, Maria Assunta Navarra, Stefania Panero, Francesca Pagnanelli. Electrochemical synthesis of nanowire anodes from spent lithium ion batteries. Electrochimica Acta. 2019; 319 ():481-489.
Chicago/Turabian StylePier Giorgio Schiavi; Luca Farina; Robertino Zanoni; Pietro Altimari; Iulia Cojocariu; Antonio Rubino; Maria Assunta Navarra; Stefania Panero; Francesca Pagnanelli. 2019. "Electrochemical synthesis of nanowire anodes from spent lithium ion batteries." Electrochimica Acta 319, no. : 481-489.
In this contribution, two different strategies are discussed to synthesize cobalt nanostructures: direct cobalt electrodeposition on a planar aluminum electrode and cobalt electrodeposition into nanoporous alumina templates generated by aluminum anodization (template electrodeposition). In the direct electrodeposition of cobalt on aluminum, cobalt nanoparticles are formed during the early stage of electrodeposition, which causes the depletion of cobalt ions near the electrode. Water reduction then takes place catalyzed by electrodeposited cobalt nanoparticles, which increases the pH near the electrode and can induce cobalt hydroxide precipitation. By varying the electrode potential and the cobalt ion concentration, the interplay between electrochemical growth of cobalt and water reduction could be controlled to induce transition from cobalt hexagonal nano-platelets to nanostructured films composed of cobalt nanoparticles and cobalt hydroxide nano-flakes. Cobalt nanowires can be synthesized by electrodeposition into nanoporous alumina templates generated by aluminum anodization. This approach typically involves the application of alumina templates produced by a two-step anodization procedure: the alumina nanoporous layer generated by a first anodization is dissolved in a chromic acid solution while a very ordered alumina nanoporous layer is produced by a second anodization stage. In accordance with previous studies, this procedure is fundamental to achieve uniform filling of the nanopores in the subsequent electrodeposition stage. In the present study, uniform filling of the nanoporous alumina generated by one-step anodization could be achieved by the electrodeposition of cobalt nanowires. This result was made possible by the application of a novel pulsed electrodeposition strategy.
Pier Giorgio Schiavi; Antonio Rubino; Pietro Altimari; Francesca Pagnanelli. Two electrodeposition strategies for the morphology-controlled synthesis of cobalt nanostructures. EMERGING TECHNOLOGIES: MICRO TO NANO (ETMN-2017): Proceedings of the 3rd International Conference on Emerging Technologies: Micro to Nano 2018, 1990, 020005 .
AMA StylePier Giorgio Schiavi, Antonio Rubino, Pietro Altimari, Francesca Pagnanelli. Two electrodeposition strategies for the morphology-controlled synthesis of cobalt nanostructures. EMERGING TECHNOLOGIES: MICRO TO NANO (ETMN-2017): Proceedings of the 3rd International Conference on Emerging Technologies: Micro to Nano. 2018; 1990 (1):020005.
Chicago/Turabian StylePier Giorgio Schiavi; Antonio Rubino; Pietro Altimari; Francesca Pagnanelli. 2018. "Two electrodeposition strategies for the morphology-controlled synthesis of cobalt nanostructures." EMERGING TECHNOLOGIES: MICRO TO NANO (ETMN-2017): Proceedings of the 3rd International Conference on Emerging Technologies: Micro to Nano 1990, no. 1: 020005.
The electrodeposition of cobalt nanowires into nanoporous alumina templates produced by one-step anodization of low-purity aluminium was investigated. Aluminium was electropolished prior anodization to generate a hexagonal cell pattern, and a tree-like structure was introduced at the aluminium/aluminium oxide interface by progressively decreasing the anodization potential following potentiostatic anodization. Pulsed electrodeposition including the periodic application of a cathodic potential pulse with constant amplitude was performed to fill the generated alumina template by cobalt nanowires. With this strategy, cathodic potential pulses with amplitude lower than −5 V (vs. Ag/AgCl) were necessary to enforce uniform and instantaneous cobalt nucleation at the bottom of template nanopores, which allowed achieving uniform filling and narrow length distribution of the electrodeposited nanowires. However, the uniform growth of the nucleating cobalt nanowires could be sustained by considerably less cathodic potential pulses (up to −1.5 V vs. Ag/AgCl). Uniform filling of the alumina template could accordingly be achieved by a two-stage-pulsed electrodeposition strategy including the application of a high cathodic pulse (<−5 V) inducing uniform and instantaneous cobalt nucleation followed by the periodic application of a lower cathodic pulse (>−1.5 V) sustaining nanowire growth. The mechanisms that govern cobalt nucleation at the bottom of nanopores and the technical advantages of the proposed nanowire synthesis strategy are discussed
Pier Giorgio Schiavi; Pietro Altimari; Antonio Rubino; Francesca Pagnanelli. Electrodeposition of cobalt nanowires into alumina templates generated by one-step anodization. Electrochimica Acta 2018, 259, 711 -722.
AMA StylePier Giorgio Schiavi, Pietro Altimari, Antonio Rubino, Francesca Pagnanelli. Electrodeposition of cobalt nanowires into alumina templates generated by one-step anodization. Electrochimica Acta. 2018; 259 ():711-722.
Chicago/Turabian StylePier Giorgio Schiavi; Pietro Altimari; Antonio Rubino; Francesca Pagnanelli. 2018. "Electrodeposition of cobalt nanowires into alumina templates generated by one-step anodization." Electrochimica Acta 259, no. : 711-722.