Novel graphene-based microporous layers (MPLs) have been developed as a possible alternative to conventional carbon black-based MPLs aiming to enhance electrical performance and durability of PEM fuel cell systems. Graphene nanoplatelets (GNPs) have been used as carbonaceous conductive phase in the ink formulation for MPL due to their low electrical resistance, high surface area and mechanical stability. The novel MPLs exhibited more homogeneous and less cracked surfaces compared to MPLs containing carbon black. Such enhanced MPL surface resulted in a better electrical contact between MPL and fuel cell electrode and a consequent lower ohmic resistance. Moreover, chemical and mechanical accelerated stress tests were developed in order to evaluate durability of the prepared samples and the most detrimental degradation mechanism. Fresh MPLs showed very similar electrochemical behaviors in running fuel cells while GNPs-based MPLs proved to be more resistant against both stress factors than conventional ones.

Photoanodes for water-splitting applications were produced by coating acid-treated Ti slabs using an aqueous dispersion of TiO 2 , polyvinyl alcohol and glycerol. Such components were adjusted to achieve a lower viscosity at a 10 s-1 shear rate, considered as representative of the dip-coating application, for the sake of reducing the final coating thickness while increasing its quality. A correlation was found between the thickness of the oxide layer and the percentage of area occupied by the crevices, which appeared, during the thermal treatment, as an effect of the liquid phase removal. Also, the adhesion appeared to be strongly related to the cracking phenomena, since less cracked samples withstood much lower weight losses during the adhesion tests. The lower adhesion of thicker coatings was found to affect the photo-catalytic performances of the photoanodes, showing lower photocurrents and efficiencies when compared with thinner ones.