STUDY OF NANOCRYSTALLINE TIO2 (ANATASE) ELECTRODE IN THE ACCUMULATIONREGIME

The formation of an accumulation layer on a nanocrystalline TiO2 (anat ase) electrode was studied by cyclic voltammetry in solutions of MCF(3 )SO(3) (M = Li, Na, K, Cs, NBu(4); Bu = n-butyl) + propylene carbonate . In the LiCF3SO3 solution, the electron accumulation is accompanied b y a reversible insertion of Li+ into the anatase lattice. Other cation s give only capacitive effects at comparable conditions. The stability of electrolyte solutions against cathodic breakdown was studied by in -situ subtractively normalized interfacial Fourier transform IR (SNIFT IR) spectroscopy. The reduction of trace water triggers solvent decomp osition. Prolonged application of voltammetric scans shifts the flatba nd potential negatively and decreases the integral voltammetric charge . The formation of the accumulation layer follows complex kinetics, wh ich are attributed to electron trapping in surface states and charge p ropagation in the nanocrystalline semiconducting skeleton.