Etude comparative d'une méthode d'électrodéposition directe et pulsée de films de TiO2 et son effet sur la dégradation photoélectrocatalytique du méthylorange (MO)

Abstract

The present study reports on the titanium dioxide (TiO2) films synthesized from TiCl3 precursor on ITO glass substrates using two electrochemical techniques, namely direct electrodeposition (DE) and pulse electrodeposition (PE). The synthesis potential was fixed at − 1.5 V during the time-On (Ton) period, while open-circuit potential is applied during the time-off (Toff) period. The effect of the technique of electrodeposition and also time-off (Toff) duration on the properties of TiO2 films and their photoelectrocatalytic activity were investigated. The obtained films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Uv-vis spectrometer, and photocurrent measurement respectively. It is found that the use of the (PE) technique at different (Toff) improves the properties of TiO2 films compared to the (DE) technique. The XRD patterns show the anatase phase with a marked preferential orientation along the (101) direction for all samples. From the SEM analysis, it is seen a significant change from big multigrain agglomerates at DE to a dense film structure and small multigrain agglomerates at different Toff. As the Time-off (Toff) decreases from 3 to 1 s , the photocurrent response rises and reach to high value about 12 mA/cm2. Compared with DE, and under UV ligh the photocatalytic property of TiO2 film synthesis via PE has been improved in the degradation of methyl orange (MO). Finally, the films deposited at low Time-off (Toff) (1 s) shows a faster degradation of MO