Three different single solid oxide fuel cells based on Ce0.85Sm0.15O2-δ electrolyte were prepared by infiltration method varying the microstructure of the porous Ce0.85Sm0.15O2-δ scaffold. La0.8Sr0.2CoO3-δ was used as the cathode and La0.3Sr0.7VO3-δ as the anode activated with CeO2 and Pd nanoparticles. The microstructure of the porous Ce0.85Sm0.15O2-δ scaffolds was characterized using modified FIB-SEM. Single cell with the finest electrolyte framework and the highest porosity of the scaffold exhibited the best power density value, 320 mW cm-2 at 873 K, using humidified hydrogen as the fuel. In contrast, the single cell with somewhat lower porosity of the scaffold and bigger Ce0.85Sm0.15O2-δ particles, but with similar pore sizes, had the best power density value, 175 mW cm-2 at 873 K, using humidified methane as the fuel.

Nitrogen-and sulfur-codoped carbon catalysts were prepared as electrocatalytic materials for the oxygen reduction reaction (ORR). Herein, we propose a novel and effective one-pot synthetic approach to prepare a NS-doped carbon catalyst by using the mixture of graphene oxide and multi-walled carbon nanotubes as a carbon support. Successful NS-doping of carbon and formation of the catalytically active sites were confirmed by X-ray photoelectron spectroscopy and with energy dispersion spectroscopy. The ORR activity of NS-codoped carbon was investigated by using a rotating disc electrode method. The NS-doped carbon shows superior ORR performance in alkaline media, and the electrocatalytic mechanism for the reduction of oxygen was well explained by density functional theory calculations of graphene sheets.

The degradation of TiO2 coatings is quantified, considering pH, temperature, illumination and operating times relevant to practical photoelectrochemical devices.

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