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The tailoring of multi-tasking perovskite oxide-based electrodes for solid oxide cells has shown growing interest. The development of flexible structures represents a crucial step towards the design of symmetric and possibly SOFC/SOEC reversible systems. In this work, low (0.5 mol%) B-site Pt-doping in a lanthanum strontium ferrite is presented as a successful approach to enhance the parent perovskite properties as both SOC air and fuel electrode. Structural, morphological and electrochemical characterizations of La0.6Sr0.4Fe0.995Pt0.005O3-δ (LSFPt005) are provided and compared to the undoped compound. LSFPt005-symmetric devices are tested as CO-SOFCs and CO2-SOECs at 850 °C, respectively, obtaining a maximum power density of 301 mW/cm2 and a current density of 0.82 A/cm2 at 1.5 V. Insights of cell operating mechanisms are provided through electrochemical impedance spectroscopy.

Due to global environmental concerns related to climate change, the need to improve the service life of structures and infrastructures is imminently urgent. Structural elements typically suffer service life reductions, leading to poor environmental sustainability and high maintenance costs. Graphene oxide nanosheets (GONSs) effectively dispersed in a cement matrix can promote hydration, refine the microstructure and improve interfacial bonding, leading to enhanced building materials’ performance, including mechanical strength and transport properties. Cement-based nanocomposites engineered with GONSs were obtained using two commercial nanofillers, a GO water suspension and a free-flowing GO nanopowder, characterized by fully comparable morphology, size and aspect ratio and different oxidation degrees (i.e., oxygen-to-carbon molar ratio), 0.55 and 0.45, respectively. The dosage of the 2D-nanofiller ranged between 0.01% and 0.2% by weight of cement. The electrical and thermal properties were assessed through electrochemical impedance spectroscopy (EIS) and a heat flow meter, respectively. The results were discussed and linked to micrometric porosity investigated by micro-computed tomography (μ-CT) and transport properties as determined by initial surface absorption test (ISAT), boil-water saturation method (BWS) and chloride ion penetration test. Extra-low dosage mortars, especially those loaded with a lower oxidation degree (i.e., 0.45GO), showed decreased permeability and improved barrier to chloride ion transport combined with enhanced thermal and electrical conductivity with respect to that of the control samples.

Mechanical performance of 3D printed ‘Rubber-like’ commercial resins are not comparable to typical vulcanized diene rubbers since they show lower strain at break. In the present work, samples made of liquid butadiene rubber have been photocured by thiol-ene chemistry and 3D printed. Morphological features and mechanical properties have been investigated by means of scanning electron microscopy (SEM), dynamic mechanical analysis (DMA) and tensile tests. The 3D printed samples show the characteristic mechanical properties of unfilled diene rubbers reaching a strain at break up to 400%.

Electrocatalytic nitrogen reduction reaction (ENRR) offers a carbon-neutral process to fix nitrogen into ammonia, but its feasibility depends on the development of highly efficient electrocatalysts. Herein, we report that Fe ion grafted on MoO3 nanorods synthesized by an impregnation technique can efficiently enhance the electron harvesting ability and the selectivity of H+ during the NRR process in neutral electrolyte. In 0.1 M Na2SO4 solution, the electrocatalyst exhibited a remarkable NRR activity with an NH3 yield of 9.66 μg h−1 mg−1cat and a Faradaic efficiency (FE) of 13.1%, far outperforming the ungrafted MnO3. Density functional theory calculations revealed that the Fe sites are major activation centers along the alternating pathway.

This work focuses on the replacement of mineral oils with bio-based waste cooking oils in rubber compounding. Two different waste cooking oils from potatoes and chicken frying process were analyzed by means of chemical and rheological tests to evaluate the chemical composition, the oxidative stability and the viscosity. Waste oils have been introduced in elastomeric compounds as substitute for typical processing aids (i.e. lubricants). Cure kinetics of rubber compounds was studied by rheological characterization. Mechanical properties of vulcanized samples were determined by means of tensile tests, hardness tests and dynamic mechanical analysis. The waste oils showed a rheological behavior very similar to the mineral oils conventionally employed in rubber manufacturing leading to almost the same processability of the resulting compound. The waste oils did not significantly affect the vulcanization kinetics of the rubber compound, as expected for conventional lubricants. Waste cooking oils and mineral oil show analogous influence on mechanical properties of cured compounds. At increasing oil content, the elongation at break and the tensile strength increased whereas the values of Elastic Modulus at 100% strain, the Storage Modulus and Shore A Hardness decreased with respect to the oil-free sample. These results are very promising, confirming the possibility to replace the mineral oils, in a good practice of circular economy.

Copyright: © 2021 by the authors. The impact of extra-low dosage (0.01% by weight of cement) Graphene Oxide (GO) on the properties of fresh and hardened nanocomposites was assessed. The use of a minimum amount of 2-D nanofiller would minimize costs and sustainability issues, therefore encouraging the market uptake of nanoengineered cement-based materials. GO was characterized by X-ray Photoelectron Spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), and Raman spectroscopy. GO consisted of stacked sheets up to 600 nm × 800 nm wide and 2 nm thick, oxygen content 31 at%. The impact of GO on the fresh admixtures was evaluated by rheology, flowability, and workability measurements. GO-modified samples were characterized by density measurements, Scanning Electron Microscopy (SEM) analysis, and compression and bending tests. Permeability was investigated using the boiling-water saturation technique, salt ponding test, and Initial Surface Absorption Test (ISAT). At 28 days, GO-nanocomposite exhibited increased density (+14%), improved compressive and flexural strength (+29% and +13%, respectively), and decreased permeability compared to the control sample. The strengthening effect dominated over the adverse effects associated with the worsening of the fresh properties; reduced permeability was mainly attributed to the refining of the pore network induced by the presence of GO.

Immiscible blends of ethylene‐propylene‐diene‐monomer (EPDM) and polyoxymethylene (POM), when EPDM is the major phase were compatibilized on the addition of an ionomer, poly(ethylene‐co‐methacrylic acid). The inclusion of the ionomer reduced the interfacial tension between the two phases, such that the diameter of the POM domains were significantly reduced to between 0.5 and 2 μm, typical of that required to toughen ductile polymers. The mechanical properties of the resultant compatibilized blends were significantly enhanced with increases in Young's modulus (↑54%), tensile strength (σ, ↑139%), elongation at break (e, ↑97%), and tensile toughness (↑500%) with increasing ionomer content, relative to EPDM rubber alone. The ShoreA hardness of the compatibilized blend was 70.1 compared with 56.8 for the immiscible binary blend and, 50.2 for neat EPDM rubber.

The impact of graphite nanoplatelets (GNPs) on the physical and mechanical properties of cementitious nanocomposites was investigated. A market-available premixed mortar was modified with 0.01% by weight of cement of commercial GNPs characterized by two distinctively different aspect ratios. The rheological behavior of the GNP-modified fresh admixtures was thoroughly evaluated. Hardened cementitious nanocomposites were investigated in terms of density, microstructure (Scanning Electron Microscopy, SEM and micro–Computed Tomography, μ-CT), mechanical properties (three-point bending and compression tests), and physical properties (electrochemical impedance spectroscopy, EIS and thermal conductivity measurements). At 28 days, all GNP-modified mortars showed about 12% increased density. Mortars reinforced with high aspect ratio GNPs exhibited the highest compressive and flexural strength: about 14% and 4% improvements compared to control sample, respectively. Conversely, low aspect ratio GNPs led to cementitious nanocomposites characterized by 36% decreased electrical resistivity combined with 60% increased thermal conductivity with respect to the control sample.

Recent improvements in additive layer manufacturing (ALM) have provided new designs of geometrically complex structures with lighter materials and low processing costs. The use of additive manufacturing in spacecraft production is opening up many new possibilities in both design and fabrication, allowing for the reduction of the weight of the structure subsystems. In this aim, polymeric ALM structures can become a choice, in terms of lightweight and demisability, as far as good thermomechanical properties. Moreover, provided that fused-deposition modeling (FDM) is used, nanosats and other structures could be easily produced in space. However, the choice of the material is a crucial step of the process, as the final performance of the printed parts is strongly dependent on three pillars: design, material, and printing process. As a high-performance technopolymer, polyether ether ketone (PEEK) has been adopted to fabricate parts via ALM, however, the space compatibility of 3D-printed parts remains not demonstrated. This work aimed to realize a nanosat polymeric structure via FDM, including all the phases of the development process: thermomechanical design, raw material selection, printing process tuning, and manufacturing of a proof of concept of a technological model. The design phase includes the application of topology optimization to maximize mass saving and take full advantage of the ALM capability. 3D-printed parts were characterized via thermomechanical tests, outgassing tests of 3D-printed parts are reported confirming the outstanding performance of polyether ether ketone and its potential as a material for structural space application.

Reversible solid oxide cell (RSOC) technology allows use of a single device to efficiently derive chemicals from power (power-to-fuel) and power from chemicals (fuel-to-power). Fuel flexibility is a key aspect, as developing SOCs able to operate on fuels other than hydrogen can ease their integration into existing infrastructure. In addition, H2O and/or CO2 reduction is favorable in SOECs as polarization losses are reduced at high temperature. Here, a composite fuel electrode, 60 wt.% La0.6Sr0.4Fe0.8Mn0.2O3-δ (LSFMn) and 40 wt.% (5 wt.% Ni)-containing Ce0.85Sm0.15O2-δ (Ni-SDC) was investigated in H2-fueled, CO-fueled SOFCs and for CO2 reduction in SOEC mode. In reducing conditions, Fe exsolved from the LSFMn perovskite formed a Ni-Fe alloy with Ni present on SDC. The composite fuel electrode showed remarkable activity for CO2 reduction with a current density output of 1.40 A cm-2 (1.5 V) at 850 °C. SOFC/SOEC cell reversibility was obtained in different CO2:CO mixtures. Electrochemical impedance spectroscopy analysis was used to better understand cell mechanisms in SOFC and SOEC mode.

Processing biological materials with 3-dimensional (3D) printers has attracted increasing interest in several research areas. At the same time, off-the-shelf solutions are increasingly available in a wider variety to meet the current market demand. However, most of the available bioprinters are closed source, thus, modifications are quite challenging or require an avoidable consultation process with the manufacturer. Furthermore, the entry prices for basic machines amount to several thousands of euros. Whereas, high-end 3D bio printers with a vast array of features are available for several hundred thousand euros. Due to the immense potential of this tool in the field of biotechnology it is important to extend the availability of this technology for research purposes in terms of adaptability and price. This ongoing work focuses on open-source 3D printer heads with the ability to extrude biological materials. The print heads include several techniques to process low as well as high viscose biomaterials such as agar and gelatin. Additionally, obstacles such as continuous substrate tempering or integration into existing 3D printers are addressed. The work presented is open source and thus freely adaptable to any user’s specific needs. Our goal is to process a diverse range of biomaterials with different print techniques.

Strain monitoring is of great interest in order to check components structural life, to prevent catastrophic failures, and, possibly, to predict residual life in case of unexpected events. In this study, strain sensing epoxy-based coatings containing carbon nanotubes (MWCNTs), graphene nanoplatelets (GNPs), and a mix of the two (MWCNT+GNP) have been produced, with the same initial electrical resistivity, and applied on glass fiber reinforced composites. Morphological, mechanical, and electrical tests have been then performed evaluating the resistance variation and the strain sensing performance of the sensors. A theoretical model to relate the resulting gauge factors to the different types of nanofillers has been applied. The results showed that all systems present a strain sensing performance with different gauge factors (and hence sensitivity) at low strain: GNP samples showed the highest gauge factor (10.3), MWCNT samples the lowest (1.5), and the mixed system lies in the middle (4.3). From analytical analysis, the value of initial distance among conductive particles was found to be 0.3 nm in the case of MWCNT and 1.2 nm for GNP, explaining why the gauge factors of the produced sensors are different.

Electrocatalytic nitrogen reduction to ammonia has attracted increasing attention as it is more energy-saving and eco-friendly. For this endeavor, the development of high-efficiency electrocatalysts with excellent selectivity and stability is indispensable to break up the stable covalent triple bond in nitrogen. In this study, we report monodisperse Cu clusters loaded on defective ZrO2 nanofibers for nitrogen reduction under mild conditions. Such an electrocatalyst achieves an NH3 yield rate of 12.13 μg h-1 mgcat.-1 and an optimal Faradaic efficiency of 13.4% at -0.6 V versus the reversible hydrogen electrode in 0.1 M Na2SO4. Density functional theory calculations reveal that the N2 molecule was reduced to NH3 at the Cu active site with an ideal overpotential. Meanwhile, the interaction between bonding and antibonding of the Cu-N bond promotes activation of N2 and maintains a low desorption barrier.

The electrocatalytic nitrogen reduction reaction (NRR) has been deemed a promising and reliable approach to massively produce ammonia under ambient conditions. A high-efficiency electrocatalyst with an excellent selectivity is highly required to reduce the multiple reaction barriers of N2 + 3H2O → 2NH3 + 1.5O2. Here, we report electrospun zirconia nanofibers as a non-noble NRR electrocatalyst to convert nitrogen to ammonia. Theoretical calculations predict that the Zr sites with oxygen vacancies are favorable for nitrogen adsorption and reduction. Experimentally, the larger concentration of oxygen defects in such an electrocatalyst allowed achieving a NH3 formation rate of 9.63 μg h−1 mgcat.−1 and an optimal faradaic efficiency of 12.1% at −0.7 V vs. the reversible hydrogen electrode in 0.1 M Na2SO4.

Intermittency of renewable energy sources can be profitably faced using efficient energy storage systems. Reversible solid oxide cells (RSOCs) able to operate with carbon-containing species are likely among the most appealing choices. Energy can be obtained by natural gas and/or biogas (SOFC mode), with useful recovery of CO2 in the exhausts. Besides, if the electrode is also active towards CO2 electrolysis (SOEC mode), CO2 is reduced to CO and O2. In this work a composite material with in-situ formed Ni-Fe alloy catalyst consisting of La1.2Sr0.8Fe0.6Mn0.4O4 Ruddlesden-Popper perovskite and Ni-Ce0.85Sm0.15O2-δ fluorite was developed as a multi-functional fuel-electrode for RSOCs. The composite electrode was tested in SOFC mode as anode for hydrogen, dry methane and carbon monoxide oxidation and showed power density outputs of 657, 668 and 527 mW/cm2 at 850 °C, respectively, together with redox stability and coking tolerance for over 120 h. In SOEC mode, it was tested as cathode and delivered 2.66 A/cm2 at 2 V in a 95:5 CO2:CO mixture, retaining a current density of 1 A/cm2 for more than 40 h.

In this work, porous complex and metal-free cathodes based on a (La0.6Sr0.4) (Cr0.5Mn0.5) O3 (LSCM) screen-printed backbone infiltrated with Ce0.9Gd0.1O2 (GDC) were fabricated for solid oxide electrolyzer cells. GDC infiltration has been optimized by structural and microstructural investigation and tested by electrochemical measurements in CO/CO2 mixtures. Infiltrated electrodes with a non-aqueous GDC solution showed the best electro-catalytic activity towards CO2 reduction, exhibiting a much lower polarization resistance, i.e., Rpol = 0.3 Ω&middot, cm2 at 900 &deg, C. The electrochemical performance of LSCM/GDCE in terms of Rpol is comparable to the best-performing Ni-YSZ cathode in the same operating conditions (Rpol = 0.23 Ω&middot, cm2).

Perovskite oxides such as ferrites have been widely investigated for their remarkable electrochemical activity as SOFC electrodes. However, their phase instability in reducing conditions remains an issue for anode application. The role of Mn substitution into B-site of La0.6Sr0.4FeO3-δ (LSF) perovskite oxide was investigated. New insights on the structural evolution of La0.6Sr0.4Fe0.8Mn0.2O3-δ (LSFMn) upon high temperature reduction were revealed. In oxidizing atmosphere, Mn substitution reduces the oxygen vacancy concentration while, switching to reducing conditions, it drives the transition from rhombohedral perovskite to single Ruddlesden-Popper phase, affecting the Fe0 exsolution. Redox-cycles of LSFMn were investigated and the properties of re-oxidized compounds were highlighted. The effect of Mn substitution on perovskite conductivity was also evaluated both in oxidizing and reducing conditions.

A structured catalyst for the dry reforming of methane (DRM) was investigated as a biogas pre-reformer for indirect internal reforming solid oxide fuel cell (IIR-SOFC). For this purpose, a NiCrAl open-cell foam was chosen as support and Ni-based samarium doped ceria (Ni-SmDC) as catalyst. Ni-SmDC powder is a highly performing catalyst showing a remarkable carbon resistance due to the presence of oxygen vacancies that promote coke gasification by CO2 activation. Ni-SmDC powder was deposited on the metallic support by wash-coating method. The metallic foam, the powder, and the structured catalyst were characterized by several techniques such as: N2 adsorption-desorption technique, X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), focused ion beam (FIB), temperature programmed reduction (H2-TPR), and Raman spectroscopy. Catalytic tests were performed on structured catalysts to evaluate activity, selectivity, and stability at SOFC operating conditions.

In cultural heritage field, significant research efforts have been recently made to improve the efficacy of anti-vegetative treatments and to reduce the environmental impact caused by biocides high concentration. According to the pro-ecological approach, this work reports a novel approach based on the encapsulation/incorporation of environmentally-friendly biocides in different silica nanosystems in order to control the development of biological patinas on outdoor cultural heritage. Two different green biocides have been selected and tested in silica nanosystems: the zosteric acid sodium salt (ZS), a natural antifoulant compound produced by Zostera marina (eelgrass), and the usnic acid (UA), a secondary metabolite produced by some saxicolous lichens. ZS was previously successfully encapsulated but never entrapped in mesoporous silica; instead, UA is, for the first time, encapsulated and in situ entrapped into the silica nanosystems in order to control the release over time. Both silica nanosystems have been characterized as far as their dimensions and superficial properties and loading capability. The antifouling activity was assessed against microorganisms from biopatinas colonising the Aurelian Walls in Rome. Our results have shown that the two nanosystems have complementary properties, thus it is possible to tune the antifouling efficiency by combining the two in different proportions.

Solid oxide photoelectrochemical cells (SOPECs) with inorganic ion-conducting electrolytes provide an alternative solution for light harvesting and conversion. Exploring potential photoelectrodes for SOPECs and understanding their operation mechanisms are crucial for continuously developing this technology. Here, ceria-based thin films were newly explored as photoelectrodes for SOPEC applications. It was found that the photoresponse of ceria-based thin films can be tuned both by Sm-doping-induced defects and by the heating temperature of SOPECs. The whole process was found to depend on the surface electrochemical redox reactions synergistically with the bulk photoelectric effect. Samarium doping level can selectively switch the open-circuit voltages polarity of SOPECs under illumination, thus shifting the potential of photoelectrodes and changing their photoresponse. The role of defect chemistry engineering in determining such a photoelectrochemical process was discussed. Transient absorption and X-ray photoemission spectroscopies, together with the state-of-the-art in operando X-ray absorption spectroscopy, allowed us to provide a compelling explanation of the experimentally observed switching behavior on the basis of the surface reactions and successive charge balance in the bulk.

A thermoresponsive Pluronic/alginate semisynthetic hydrogel is used to bioprint 3D hepatic constructs, with the aim to investigate liver-specific metabolic activity of the 3D constructs compared to traditional 2D adherent cultures. The bioprinting method relies on a bioinert hydrogel and is characterized by high-shape fidelity, mild depositing conditions and easily controllable gelation mechanism. Furthermore, the dissolution of the sacrificial Pluronic templating agent significantly ameliorates the diffusive properties of the printed hydrogel. The present findings demonstrate high viability and liver-specific metabolic activity, as assessed by synthesis of urea, albumin, and expression levels of the detoxifying CYP1A2 enzyme of cells embedded in the 3D hydrogel system. A markedly increased sensitivity to a well-known hepatotoxic drug (acetaminophen) is observed for cells in 3D constructs compared to 2D cultures. Therefore, the 3D model developed herein may represent an in vitro alternative to animal models for investigating drug-induced hepatotoxicity.

In the frame of the HERACLES (HEritage Resilience Against CLimate Events on Site) project, a set of cultural heritage sites was studied to improve their resilience against climate events. The mediaeval Town Walls of Gubbio, in the centre of Italy, are among these. Over the centuries, several factors including environmental actions and structural and material repairs have produced different criticalities, involving both structure and materials. A severe problem consists in the progressive degradation of the mortars binding the masonry. Since the wall body structure behaves/reacts properly only if the cohesion between mortar and stones is sufficiently large, it follows that mortars degradation represents a quite significant issue that deserves a special attention. The present work focuses on the characterization of the mortars sampled in various parts of the Walls, corresponding to different historical periods, restoration measures and interventions. They were characterized to determine the corresponding mineralogical and chemical compositions along with morphological features and to investigate their mechanical properties. For that purpose, penetrometric and sclerometric tests on site and ex situ laboratory techniques, such as X-ray diffraction, polarized light microscopy, scanning electron microscopy, thermogravimetry and differential thermal analysis, were used to examine the weathering effects on mortars and more generally their degradation state, in order to plan appropriate restoration and repair actions.

In this study an extensive experimental campaign has been conducted on mortars modified with nano-Graphite (nG) aimed to assess the properties of the resulting nanocomposites in terms of density, microstructure, flexural and compressive strength, damping ratio, thermal and electrical conductivity. Permeability properties were also investigated in terms of initial surface absorption, water contact angle, volume of permeable voids and chloride ion diffusion. Premixed mortars have been modified with different dosages of commercial nG, i.e. 0.01%, 0.1%, or 0.2% by weight of cement. The rheological behavior of the fresh admixtures has been investigated. Specimens were casted in bars and hardened in water for 7, 14 or 28 days. At 28 days all samples showed enhanced density (i.e. up to 16%) and mechanical properties (i.e. up to 30%) combined to remarkable decreased overall permeability. The lowest dosage of nG (i.e. 0.01% by weight of cement) resulted in cement nanocomposites with the highest increase in damping ratio, electrical and thermal conductivity, 68%, 30% and 55%, respectively.

An innovative concept of a low-cost pH optode with working volumes of less than 150 µL is presented. The pH monitoring is based on the color changing effect of pH indicators. The optode includes an RGB color sensor patch TCS34725 from Adafruit, a controllable LED and reactor slides and is addressed by a self-written LabVIEW© software. Utilizing the hue value of the HSV color model, it is possible to analyze the color change of the indicator and estimate the pH value of the analyzed samples by exploiting sigmoidal fit models. Measurements carried out with phenol red and DMEM (Dulbecco's Modified Eagle's Medium) reported a standard error of calibration in the physiologic pH range (6.5–7.5) of ±0.04 pH units.

In this work, hydrophilic silver nanoparticles (AgNPs), bifunctionalized with citrate (Cit) and L-cysteine (L-cys), were synthesized. The typical local surface plasmon resonance (LSPR) at &lambda, max = 400 nm together with Dynamic Light Scattering (DLS) measurements (&lt, 2RH&gt, = 8 &plusmn, 1 nm) and TEM studies (&Oslash, = 5 &plusmn, 2 nm) confirmed the system nanodimension and the stability in water. Molecular and electronic structures of AgNPs were investigated by FTIR, SR-XPS, and NEXAFS techniques. We tested the system as plasmonic sensor in water with 16 different metal ions, finding sensitivity to Hg2+ in the range 1&ndash, 10 ppm. After this first screening, the molecular and electronic structure of the AgNPs-Hg2+ conjugated system was deeply investigated by SR-XPS. Moreover, in view of AgNPs application as sensors in real water systems, environmental safety assessment (ecosafety) was performed by using standardized ecotoxicity bioassay as algal growth inhibition tests (OECD 201, ISO 10253:2006), coupled with determination of Ag+ release from the nanoparticles in fresh and marine aqueous exposure media, by means of ICP-MS. These latest studies confirmed low toxicity and low Ag+ release. Therefore, these ecosafe AgNPs demonstrate a great potential in selective detection of environmental Hg2+, which may attract a great interest for several biological research fields.

Copper and gadolinium doped ceria (GDC) anode supported fuel cells were co-sintered at relatively low temperature (900 °C) and successfully tested in the intermediate temperature (IT) range. The GDC electrolyte densification was promoted by a compressive strain induced by increasing the anodic thickness and was evaluated by SEM investigation. Instead of more commonly used La0.8Sr0.2Fe0.6Co0.4O3-δ, strontium and copper-doped lanthanum ferrite La0.8Sr0.2Fe0.8Cu0.2O3-δ (LSFCu) mixed with 30 wt% GDC (LSFCu-GDC) was employed as cathodic material. Preliminary tests on Cu-GDC/GDC/LSFCu-GDC single cells showed promising results at temperature as low as 650 °C using hydrogen as fuel.

High materials costs and low performance are the persisting bottlenecks that significantly affect the microbial fuel cells (MFCs) applications. The membraneless single-chamber MFC with an air-breathing cathode is a simple configuration where the bacteria play a role in both the anodic and cathodic processes. However, the microbial cathodic semi-reaction is the rate-determining step that can impair the advantage of the natural availability of oxygen in the air. In this work, the microbial catalysis was improved adding cerium oxide nanoparticles (nanoceria) in carbon-based cathodes of air-breathing MFCs, boosting their performance. Two kinds of nanoparticles were tested: CeO2 and Sm-doped CeO2 (Sm-CeO2) on carbon powder, using pristine carbon powder cathodes as a control. The energy generated was 113, 65 and 31 mWh m−2, for Sm-CeO2, CeO2 and control MFCs, respectively, during four subsequent fed cycles of 0.036 mol L−1 Na-acetate in carbonate buffer solution. The better performance of MFCs was correlated to the oxygen preferential and controlled entrapping and release via Ce4+/3+ redox reaction at the carbon particle surface, as well as to the increased cathode active specific surface area. The achieved results suggest that nanoceria can act as oxygen storage for bacteria in the anaerobic biofilm colonizing the cathode.

We have synthesized two-dimensional carbon nanoparticles by oxidative unfolding of C60 fullerene and demonstrated that the selective sensitivity of this material to the presence of Cu2+ and Pb2+, resulting in variations of the fluorescence intensity and optical absorbance, is related to nanoparticle aggregation processes. This mechanism occurs through coordination of the metal ions and, above a certain ion concentration, leads to precipitation of the carbon material that reduces the metal content in solution. The effect has been characterized by optical measurements while Atomic Absorption Spectroscopy have been carried out for a precise assessment of the real ion concentration in solution.We have synthesized two-dimensional carbon nanoparticles by oxidative unfolding of C60 fullerene and demonstrated that the selective sensitivity of this material to the presence of Cu2+ and Pb2+, resulting in variations of the fluorescence intensity and optical absorbance, is related to nanoparticle aggregation processes. This mechanism occurs through coordination of the metal ions and, above a certain ion concentration, leads to precipitation of the carbon material that reduces the metal content in solution. The effect has been characterized by optical measurements while Atomic Absorption Spectroscopy have been carried out for a precise assessment of the real ion concentration in solution.

Proton-conducting oxides offer a promising electrolyte solution for intermediate temperature solid oxide fuel cells (SOFCs) due to their high conductivity and low activation energy. However, the lower operation temperature leads to a reduced cathode activity and thus a poorer fuel cell performance. La0.8Sr0.2MnO3−δ (LSM) is the classical cathode material for high-temperature SOFCs, which lack features as a proper SOFC cathode material at intermediate temperatures. Despite this, we here successfully couple nanostructured LSM cathode with proton-conducting electrolytes to operate below 600°C with desirable SOFC performance. Inkjet printing allows depositing nanostructured particles of LSM on Y-doped BaZrO3 (BZY) backbones as cathodes for proton-conducting SOFCs, which provides one of the highest power output for the BZY-based fuel cells below 600°C. This somehow changes the common knowledge that LSM can be applied as a SOFC cathode materials only at high temperatures (above 700°C).

TiO2 coatings on AA6082 aluminium alloy were obtained at low temperature (80 and 100°C) by the sol-gel dip-coating technique starting from titanium tetra-isopropoxide solution in ethyl alcohol. The preparation was carried out in the presence of acetic acid with both functions of catalyst and chelating agent. The curing temperatures used for these coatings are between 80 and 100°C, low enough to make such coatings suitable to incorporate additives such as organic inhibitors or polymeric nanoparticles. The coated samples were characterised by scanning electron microscopy and energy-dispersive spectroscopy, atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy (EIS). Compact coatings with a thickness of 500 nm, consisting of amorphous and nearly stoichiometric titanium dioxide, were obtained. EIS results revealed an effective corrosion protection of the substrate for more than 120 h of immersion in 3.5 wt-% NaCl aqueous solution.

One of the main problems for the deployment of intermediate-temperature solid oxide fuel cells (IT-SOFCs) is their chemical stability, since most of SOFCs contain alkaline-earth metal elements (Ba, Sr and Ca) that easily react with CO2 forming carbonates. To tackle this problem, we performed a systematic investigation of a series of Ni0.7Co0.3O–Ce0.8Sm0.2O1.9 (NC3O-SDC) composite cathodes, which are CO2-stable and alkaline-earth-free compounds. In this work, NC3O-xSDC (with x = 0-60 wt.%) were synthesized by self-propagating combustion method and investigated as new cathode materials for oxygen-ion conducting SOFCs. The thermal stability and phase structure of NC3O polycrystalline powders were studied using TG-DTA and XRD analysis, which confirmed that NC3O is chemically compatible with SDC. The electrical conductivity and thermal expansion of the NC3O-xSDC samples were measured. The electrochemical properties of NC3O-xSDC/SDC/NC3O-xSDC cells were studied using electrochemical impedance spectroscopy measurements. Among the NC3O-xSDC series, NC3O-30SDC showed a minimum in cathode polarization resistance, being 0.071 Ωcm2 at 800. A maximum power density of 200 mWcm-2 at 600 was obtained using anode-supported SOFCs.

International audience; Bare and Al2O3-coated austenitic steel samples are exposed to lead-fast-reactor relevant corrosive conditions.Selective leaching of Ni, Mn and Cr is observed in bare samples exposed to high temperature stagnant lead(550 DC, 10et8722;8 wt.percent oxygen, 1000 and 4000 h). By contrast, corrosion is not observed in either pristine (4000 h)or irradiated (1000 h) coated samples. Further characterization and testing methods include SEM, TEM, STEM,EDS, cyclic nanoimpact, microindentation, scratch, and thermal cycling. Overall, the results show that thecoatings retain structural integrity under the conditions investigated, which is a crucial prerogative for corrosionprotection with ceramic coatings.