Manuela Sonja Killian oral presentation (SN3-Wed2-2-3)
Novel p-type anodic NiO sponges for photocatalytic applications
Friedrich-Alexander-University Erlangen-Nürnberg, Martensstr. 7, 91058 Erlangen, Germany
Dye sensitized photocathodes have the potential to significantly contribute to the efficiency of the solar light-to-current conversion in photoelectrochemical cells (PECs). Suitable photoactive cathodes for hydrogen production should consist of earth-abundant elements and show high incident photon-to-current conversion efficiencies (IPCEs). NiO is a photostable and cheap material, has suitable band positions for catalyzing hydrogen evolution and shows sufficiently high photocurrents.
Anodic nanostructures facilitate fast charge separation and a directional charge transport. We developed a novel, highly porous, sponge-like nanoarchitecture of NiO, reaching layer thicknesses of up to 6.5mm. The nanosponge shows high thermal stability, the surface morphology was not altered even after exposure to 600°C. XPS, XRD and ToF-SIMS depth profiling confirmed that the oxide composition is NiO. The oxide exhibits p-type behaviour and a bandgap of 3.4eV. Several dyes for p-type photocatalytic materials were tested in combination with the newly developed NiO nanosponge and their adsorption to the oxide was investigated by ToF-SIMS and XPS. The developed dye sensitized p-type NiO based cathodes are promising for application in tandem cells for photocatalysis and water splitting.