Photoelectrochemical reactivity of a hybrid electrode composed of polyoxophosphotungstate encapsulated in titania nanotubes

A polyoxometalate-modified titania hybrid electrode with a tailored microstructure is studied for its photoelectrochemical applications. A highly ordered TiO2 nanotube array is prepared by low-voltage anodization followed by calcination. Functionalized polyoxophosphotungstate-titania/titanium (POW-TiO2/Ti) hybrid electrodes are synthesized by encapsulating POW nanoaggregates in the TiO2 nanotube array. The morphological characteristics and structures of POW-TiO2 composites are examined by field-emission scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, and Fourier transform IR spectroscopy. The photoelectrochemical properties of the POW-TiO2/Ti electrodes are investigated by anodic polarization photocurrent-response measurements. Photocatalytic/photoelectrocatalytic reactivities of microstructured and nanotubular POW-TiO2/Ti photoanodes are studied for their use in the degradation of recalcitrant organic pollutants.