Functional Interfaces in Pure and Blended Oxide Nanoparticle Networks: Recombination versus Separation of Photogenerated Charges

Solvent-mediated particle aggregation was employed to produce nanoparticle networks containing a high abundance of functional interfaces. Using electron paramagnetic resonance spectroscopy (EPR), we experimentally observed that the intentional attachment of vapor-grown ZrO2 nanocrystals to TiO2 particle surfaces yields networks of intermixed nanoparticles with substantially improved charge separation properties. The superior performance holds also in comparison to homogeneous ZrO2 and TiO2 nanoparticle networks that exhibit a higher charge recombination loss in comparison to powders of unconnected nanocrystals.