Microbial fuel cell performance of graphitic carbon functionalized porous polysiloxane based ceramic membranes.

Proton-conducting porous ceramic membranes were synthesized via a polymer-derived ceramic route and probed in a microbial fuel cell (MFC). Their chemical compositions were altered by adding carbon allotropes including graphene oxide (GO) and multiwall carbon nanotubes into a polysiloxane matrix as filler materials. Physical characteristics of the synthesized membranes such as porosity, hydrophilicity, mechanical stability, ion exchange capacity, and oxygen mass transfer coefficient were determined to investigate the best membrane material for further testing in MFCs. The ion exchange capacity of the membrane increased drastically after adding 0.5 wt% of GO at an increment of 9 fold with respect to that of the non-modified ceramic membrane, while the oxygen mass transfer coefficient of the membrane decreased by 52.6%. The MFC operated with this membrane exhibited a maximum power density of 7.23 W m-3 with a coulombic efficiency of 28.8%, which was significantly higher than the value obtained using polymeric Nafion membrane. Hence, out of all membranes tested in this study the GO-modified polysiloxane based ceramic membranes are found to have a potential to replace Nafion membranes in pilot scale MFCs.

Hybrid metal-Cu2S nanostructures as efficient co-catalysts for photocatalytic hydrogen generation.

In this communication, we present a new synthesis method for the fabrication of hybrid metal-Cu2S (M = Pt, FePt) nanocrystals (HNs). The metal-Cu2S HNs were investigated in photocatalytic hydrogen generation as effective co-catalysts on TiO2. The Pt-Cu2S/TiO2 catalyst showed a higher hydrogen generation rate compared with a pure TiO2 catalyst. This enhancement is attributed to the synergistic effects between Cu2S and Pt, which significantly improve the light absorption ability and the charge separation activity.