Sodium alginate (SA) and chitosan (CS) were modified by Fe^3＋ and glutaraldehyde as linking reagents to prepare CuTsPc-SA/mCS bipolar membrane (BPM). The copper phthalocyanine tetrasulfonic acid (CuTsPc) was added into the SA cation exchange layer to improve the ion exchange capacity and promote water splitting at the interlayer of the CuTsPc-SA/mCS BPM. X-ray photoelectron energy spectrum (XPS) was used to characterize the CuTsPc-SA cation exchange membrane. The experimental results indicated that the ion exchange capacity and hydrogen ion transmigration rate of the CuTsPc-SA cation exchange membrane were increased. In comparison with the mSA/mCS BPM modified by Fe^3＋ or ferrocene, the membrane impedance and IR drop of the CuTsPc-SA/mCS BPM were decreased. The cell voltage was only 5.6 V at a higher current density of 120 mA•cm^―2. When the concentration of CuTsPc was 2.5%, the CuTsPc-SA/mCS BPM was stable in an acid solution ([H^＋]＜8 mol/L).

Key words: bipolar membrane, sodium alginate, chitosan, copper phthalocyanine tetrasulfonic acid