Electrochemically assisted preparation of graphitic carbon nitride nanosheet membranes for efficient water purification

The development of a highly effective nanofiltration membrane for water purification is crucial for wastewater recovery. The graphitic carbon nitride (g-C3N4) membrane can be an ideal candidate for advanced water treatment due to its intrinsic porous structure and superior physicochemical stability. However, the developments of the g-C3N4 membranes are limited by their traditional preparation methods involving complicated processes, long reaction time and high-temperature conditions. A simple electrochemical-assisted strategy for the rapid preparation of the g-C3N4 nanosheet membranes at room temperature has been developed in this study. The ultra-thin g-C3N4 membrane with a uniform structure can be synthesized within 40 min, which is at least 7 times quicker compared to the traditional methods. The as-prepared g-C3N4 membrane shows a high water flux rate of ∼ 90 L m−2·h−1·bar−1. Simultaneously, an excellent rejection rate of 99.1 % toward Evans blue is achieved based on the synergistic effect of size sieving and electrostatic repulsion. The breakthrough in the preparation method of g-C3N4 nanosheet membranes in this work is of great significance to the development of g-C3N4 membranes in the field of water purification.