The exploration of interfacial phenomena in metal oxide nanoparticle networks and the identification of related synergistic effects are vital to the development of functional particle systems. Corresponding insights are highly important for applications that focus on the conversion of photon energy to chemical processes and/or electric energy.1 For this reason we investigated the photoelectronic properties of TiO2, SnO2 and ZrO2 interfaces inside powders quantitatively. In order to obtain metal oxide nanoparticles with narrow size distributions we employed the metal organic chemical vapor synthesis method in a flow reactor system. Structure, morphology and spectroscopic properties (UV-Vis, Electron Paramagnetic Resonance) of the resulting particles were characterized.2To create the desired nanoparticle blends with a high abundance of functional TiO2-SnO2 interfaces we employed the self-assembly of oppositely charged particles2,3 in colloidal dispersion using formic acid for the adjustment of surface charge. In comparison to mixed particle systems prepared in pure water the mixed particle systems which were obtained via surface charge-directed aggregation show a substantially increased yield for photogenerated hole centers. The extremely high concentration of SnO2-TiO2 heterojunctions actually gives rise to an enhanced cross section for the separation of photogenerated charges.[1] Kisch, H., Angew. Chemie. Int. Ed. 52 (2013) 812.[2] Siedl, N. et al.; J.Phys. Chem. C, 2012, 116, 22967.[3] L�pez-L�pez, J. M. et al.; Soft Matter 2006, 2 1025.

Metal oxide particle networks from powder mixtures: Generation of functional heterojunctions via surface charge induced heteroaggregation

246th National Meeting (2013)

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