Study on Photo-Catalytic Properties of Nano-TiO2/Anthraquinone in a Sandwich-Type Bipolar Membrane

Abstract

A sandwich-type bipolar membrane (BPM) was prepared by a paste method, consisted of an anionic layer, a cationic layer and a catalytic intermediate layer. Carboxymethylcellulose (CMC) and chitosan (CS) were modified by Fe3+ and glutaraldehyde respectively to prepare the mCMC/mCS BPM. Semiconductor photocatalyst combined with photosensitizes was applied to improve the water dissociation at the intermediate layer of the bipolar membrane, using nanometer-sized titanium dioxide (TiO2) as a photocatalyst and anthraquinone (Anth) as a photosensitize. The impedance of bipolar membrane and the performance of hydrolysis influenced by the composite catalytic center were studied. The sandwich-type BPM exhibited several good properties, such as higher efficiency for the water splitting at the intermediate layer, protons and hydroxyl ions permeabilities, higher operational current density as well as lower impedance and potential drop. Under the UV illumination, the corresponding voltage reached as low as 5.0V when the operational current density was 125mA/cm2.