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Microbial fuel cell (MFC) is a useful biotechnology to produce electrical energy from different organic substrates. This work reports for the first time results of the application of single chamber MFCs to generate electrical energy from diluted white wine (WWL) and red wine (RWL) lees. Power obtained was of 8.2 W m −3 (262 mW m −2 ; 500 Ω) and of 3.1 W m −3 (111 mW m −2 ; 500Ω) using white and red wine lees, respectively. Biological processes lead to a reduction of chemical oxygen (TCOD) and biological oxygen demand (BOD 5 ) of 27% and 83% for RWL and of 90% and 95% for WWL, respectively. These results depended on the degradability of organic compounds contained, as suggest by BOD 5 /TCOD of WWL (0.93) vs BOD 5 /TCOD of RWL (0.33), and to the high presence of polyphenols in RWL that inhibited the process. Coulombic efficiency (CE) of 15 ± 0%, for WWL, was in line with those reported in the literature for other substrates, i.e. CE of 14.9 ± 11.3%. Different substrates led to different microbial consortia, particularly at the anode. Bacterial species responsible for the generation of electricity, were physically connected to the electrode, where the direct electron transfer took place.

We fabricate perovskite based solar cells using CH3NH3PbI3−xClx with different hole-transporting materials. The most used 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenylamine)9,9′-spirobifluorene (Spiro-OMeTAD) has been compared to the poly(3-hexylthiophene-2,5-diyl) (P3HT). By tuning the energy level of P3HT and optimizing the device's fabrication, we reached 9.3% of power conversion efficiency, which is the highest reported efficiency for a solar cell using P3HT. This result shows that P3HT can be a suitable low cost hole transport material for efficient perovskite based solar cells.

Pt clusters were deposited by an impregnation process on three carbon supports: multi-wall carbon nanotubes (MWNT), single-wall carbon nanohorns (SWNH), and Vulcan XC-72 carbon black to investigate the effect of the carbon support structure on the possibility of reducing Pt loading on electrodes for direct methanol (DMFC) fuel cells without impairing performance. MWNT and SWNH were in-house synthesised by a DC and an AC arc discharge process between pure graphite electrodes, respectively. UV–vis spectrophotometry, scanning and transmission electron microscopy, X-ray diffraction, and cyclic voltammetry measurements were used to characterize the Pt particles deposited on the three carbon supports. A differential yield for Pt deposition, not strictly related to the surface area of the carbon support, was observed. SWNH showed the highest surface chemical activity toward Pt deposition. Pt deposited in different forms depending on the carbon support. Electrochemical characterizations showed that the Pt nanostructures deposited on MWNT are particularly efficient in the methanol oxidation reaction.

Composite Nafion-based membranes were prepared and characterized, using an organosilane derivative (sulfonated diphenylsilanediol, SDPSD) as a filler. The physico-chemical and electrochemical properties of the composite membranes were investigated using differential scanning calorimetry (DSC), field emission scanning electron microscopy (FE-SEM), water uptake (W.U.), and electrochemical impedance spectroscopy (EIS). Both conductivity values and thermal features of the composite demonstrated that the presence of SDPSD as a filler significantly modified the properties of the Nafion matrix, allowing to increase its performance in terms of proton conductivity as well as thermal stability. In particular, the interaction between Nafion and SDPSD was found to improve the mechanical stiffness of the Nafion matrix, leading to an increase in the temperature range at which the Nafion membrane maintains proper hydration requirements and hence satisfactory proton conductivity values, allowing its use as an electrolyte in Polymer Electrolyte Fuel Cells operating at intermediate temperatures.

A nanocomposite re-cast Nafion hybrid membrane containing titanium oxide calcined at T = 400 oC as an inorganic filler was developed in order to work at medium temperature in polymer electrolyte fuel cells (PEFCs) maintaining a suitable membrane hydration under fuel cell operative critical conditions. Nanometre TiO2 powder was synthesized via a sol-gel procedure by a rapid hydrolysis of Ti(OiPr)4. The membrane was prepared by mixing a Nafion-dimethylacetammide (DMAc) dispersion with a 3 wt% of TiO2 powder and casting the mixture by Doctor Blade technique. The resulting film was characterised in terms of water uptake and ion exchange capacity (IEC). The membrane was tested in a single cell from 80 to 130 oC in humidified H2/air. The obtained results were compared with the commercial Nafion115 and a home-made recast Nafion membrane. Power density values of 0.514 and 0.256Wcm-2 at 0.56V were obtained at 110 and 130 oC, respectively, for the composite Nafion-Titania membrane. Preliminary tests carried out using steam reforming (SR) synthetic fuel at about 110 oC have highlighted the benefit of the inorganic filler introduction when PEFC operates at medium temperature and with processed hydrogen. © 2005 Elsevier B.V. All rights reserved.