Fabrication of efficient and cost effective multi-podal TiO2 nanotube array photo-anode on replacing conventional platinum counter electrode by graphite foil

Abstract

Cost effective graphite foil (GF) were used as counter electrode (CE) to fabricate multi-podal TiO2 nasnotube array (MTNA) via electrochemical anodization route. Moreover, the MTNA fabricated while using GF as CE were greater in length than that obtained while using PF as CE. Correspondingly, the changed dimensional parameters in such anodized MTNA prepared photo-anode resulted appreciable enhancement in photocurrent density from 18 to 21.8 mA/cm2 under 1 sun illumination (100 mW/cm2). The use of platinum foil as counter electrode shows feeble degree of deterioration despite its appreciable nature of inertness. The corresponding amount of platinum lost by the CE is being added to the electrolyte which in turn contaminates the MTNA in the working electrode. As such nanotubes with purposeful composition are not being produced on using platinum foil as CE. Replacing platinum foil with graphite one, the purposeful composition in nanotubes is possible despite GF shows deterioration as well, as graphite (carbon) gets evaporated on annealing at 500 °C to obtain a desired anatase phase which is not possible in case of platinum contamination.