REDOX PROPERTIES OF NANOPOROUS TIO2 (ANATASE) SURFACE-MODIFIED WITH PHOSPHOTUNGSTIC ACID

Nanostructured anatase TiO2 electrodes surface modified with inorganic metal oxide clusters, i.e., phosphotungstic acid (PWA), was studied b y XPS and spectroelectrochemistry. The surface modifiers were electroa ctive and could be addressed reversibly by changing the applied bias. The formation of new states in the electronic structure of TiO2 and th e PWA was monitored by XPS using a novel preparation technique. The co loration efficiency of the deposit was about 20 cm(2)/C. Prolonged ele ctrochemical cycling degraded the electrical contact between the PWA a nd the TiO2 surface. (C) 1998 Elsevier Science S.A. All rights reserve d.