Makara Seri Sains (Apr 2009)
Development of A Novel Methode for COD (Chemical Oxygen Demand) Measurement based onPhotoelectrochemical Cell: Characterization of TiO2/ITO Film Working Electrode
Abstract
Nanosize TiO2 film,immobilized on an ITO (Indium Tin Oxide) glass, was successfully fabricated. The film was prepared by a dip coatingtechnique in a hydrothermal sol-gel system and subjected to a heat treatment at 100°C up to 450°C. Characterization ofthe film by XRD, AFM, BET methods revealed the occurrence of anatase form and 9.64 nm in crystallite size; havingthree dimensional profile and roughness with height of typically 9.8 nm; and surface area of 58.21 m2/g. The film thenwas employed as a working electrode in a photo electrochemical system (PES). This PES generated a photocurrent thatproportional to the organic chemical concentration in the water sample. Integration of the photocurrent versus timegives a charge (Q) that represent the event of complete mineralization of organic chemical in the TiO2 surface and canbe correlated to the Chemical Oxygen Demand (COD) of measured water. This system has a potential to be developedfor a novel COD sensor.
