Euplectella aspergillum inspired PPAN@g-C3N4 fibrous membrane with abundant micro/nano pores for high-throughput wastewater purification

Abstract

Integrating photocatalytic degradation and membrane separation is a crucial approach to water purification. Here, inspired by Euplectella aspergillum, we presented an electrospinning fibrous membrane containing polyacrylonitrile (PAN), graphitic carbon nitride (g-C3N4) particles, and polyvinylpyrrolidone (PVP). The g-C3N4 particles undertook the task of photocatalytic degradation for various contaminants. The PVP molecules assumed the role of pore-forming agent for providing additional channels for high-throughput wastewater purification. Furthermore, the micro/nano porous structure of the PPAN@g-C3N4 fibers promoted the exposure of the photocatalytic active center of the g-C3N4 particles, improving the light absorption capacity and enhancing photocatalytic performance. Hence, the prepared PPAN@g-C3N4 fibrous membrane possessed excellent separation properties for the oil/water mixture (53,555 ± 3241 L m−2 h−1 bar−1) and oil-in-water emulsion (103,689 ± 13,286 L m−2 h−1 bar−1), and maintained its initial separation performance after cyclic separation. Moreover, the membrane showed excellent photocatalytic performance for different pollutants, among which the photocatalytic efficiency of RhB, MB, and MG was about 100 %. After 7 consecutive photocatalytic degradation of RhB, the efficiency remained above 95 %. Meanwhile, the antibacterial efficiency was more than 87 %. The combination of high-throughput separation performance and excellent catalytic performance exemplifies its potential attractiveness for practical wastewater purification.