Photoactivity and scattering behavior of anodically and cathodically deposited hematite photoanodes – a comparison by scanning photoelectrochemical microscopy

Two differently processed nanostructured hematite electrodes were prepared by anodic and cathodic electrodeposition in presence of small organic molecules as structure-directing agents on a divided conductive glass. As the materials were on the same support, all subsequent processing steps were identical. The materials were characterized with respect to light absorption. Raman spectroscopy and X-ray photoelectron spectroscopy were used for structural characterization. The morphology was assessed by scanning electron microscopy. The photoelectrochemical properties of both materials were compared by scanning photoelectrochemical microscopy in one experiment. Besides absorption properties, the scatttering properties of the materials were compared. It is found that the more rough cathodically deposited material exhibited higher light scattering efficiency and thus showed a 4.5 times higher average photocurrent.

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