Preparation and characterization of bipolar membranes modified by photocatalyst nano-ZnO and nano-CeO2

Nano-ZnO–CeO2 coupled semiconductor was added into the chitosan (CS) anion exchange membrane layer to prepare the PVA–CMC/nano-ZnO–CeO2–CS (here, PVA: polyvinyl alcohol; CMC: carboxymethyl cellulose) bipolar membrane (BPM), and the prepared BPM was characterized by SEM, J–V characteristics, electronic universal testing machine, contact angle measurement and so on. Experimental results showed that nano-ZnO–CeO2 exhibited better photocatalytic property for water splitting at the interlayer of BPM than nano-ZnO or nano-CeO2, which could greatly reduce the membrane impedance of the BPM. Under the irradiation of high-pressure mercury lamps, the cell voltage of PVA–CMC/nano-ZnO–CeO2–CS BPM decreased by 0.7 V at the current density of 60 mA/cm2, and the cell voltages of PVA–CMC/nano-ZnO–CS BPM and PVA–CMC/nano-CeO2–CS BPM were only reduced by 0.3 V and 0.5 V, respectively. Furthermore, the hydrophilicity, and mechanical properties of the modified BPM were increased.