Ultra-thin graphene oxide intermediate layer for bipolar membranes using atomizing spray assembly

Bipolar membranes have interesting applications because they allow to produce an acid and a base from a neutral salt feed stream. Water dissociation occurred in intermediate layer plays a very important role for efficient bipolar membrane processes. Development of a strong hydrophilic and low resistance intermediate layer is crucial to further improve bipolar membrane efficiency. In this work, an utra-thin graphene oxide (GO) intermediate layer was successfully prepared by an atomizing spray assembly technique, which has greatly improved the water dissociation capacity. An optimal voltage obtained from GO -based bipolar membrane was only 1.85 V at 100 mA/cm(2), which was far lower than those previously reported. An electrodialysis test also showed that the H+ concentration was higher than that in a bipolar membrane without GO as an intermediate layer. These clearly indicated that GO was an effective catalyst for water dissociation and could significantly reduce the energy consumption of such a bipolar membrane. The preliminary performances suggested the great prospect of these GO-based membranes for bipolar membrane electrodialysis. (C) 2017 Elsevier B.V. All rights reserved.