João E. Benedetti

Enhancement of photocurrent generation and open circuit voltage in dye-sensitized solar cells using Li+ trapping species in the gel electrolyte

The influence of the addition of 12-crown-4 ether in a gel polymer electrolyte based to a PEO copolymer and its application in dye sensitized solar cells were investigated. Introduction of these Li+ trapping species brought beneficial contributions to both V(oc) and J(sc) values, increasing the devices performance.

Synthesis and characterization of a quaternary nanocomposite based on TiO2/CdS/rGO/Pt and its application in the photoreduction of CO2 to methane under visible light

‘Together we are stronger’ In this work, the preparation of the quaternary nanocomposite TiO2/CdS/rGO/Pt is reported along with its application, for the first time, as a catalyst for the photocatalytic reduction of carbon dioxide (CO2) to methane (CH4). TiO2/CdS nanoparticles and Pt nanoparticle-decorated reduced graphene oxide sheets (rGO/Pt) were synthesized separately and characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), Raman spectroscopy, UV-vis spectroscopy and photoelectrochemical experiments. Hydrocarbon samples were collected and analysed using gas chromatography (GC). After 5 hours of illumination under visible light, 0.11 μmol of CH4 was produced at an average production rate of 0.0867 μmol h−1, which is higher than the production of CH4 measured from the TiO2/CdS and the TiO2/CdS/Pt control samples. The photoelectrochemical experiments confirmed that the presence of rGO sheets in the nanocomposite enhanced the electrochemical and photocatalytic properties of the nanocomposite as a result of rapid electron transport and the inhibition of charge recombination.

Polymer electrolytes for dye-sensitized solar cells

Abstract: Polymer electrolytes or gel-type polymer electrolytes are interesting alternatives to substitute liquid electrolytes in dye-sensitized solar cells (DSSC). The interest in this research field is growing, reflected in the increased number of papers published each year concerning these materials. This chapter presents a brief review of the history and development of polymer electrolytes aiming at the application in DSSC. Recent improvements achieved by modifications of the composition and by introduction of additives such as inorganic nanofillers, organic molecules and ionic liquids are described. The stability of DSSC assembled with these materials, and scaling-up of such devices are also discussed.