Durable photocatalytic membrane of PAN/TiO2/CNT for methylene blue removal through a cross-flow membrane reactor

Abstract

PAN/TiO₂/CNT and PAN/TiO₂/CNT-PVA composite nanofibrous membranes with photocatalytic activity were successfully synthesized using electrospinning. The effect of CNT concentration and PVA coating on the membrane surface toward the membrane performances was investigated. TiO₂ anatase phase was exist on the respective membranes. SEM morphological investigation revealed the random orientation of the nanofibers with beads decorated in each strand. The PAN/TiO₂/CNT composite nanofiber membrane exhibited high performance for the removal of cationic organic dye methylene blue (MB) in a cross-flow photocatalytic membrane reactor under low power visible light of LED lamp (14.5 W) and a constant pollutant flow rate of 0.21 L/min. The presence of TiO₂/CNT photocatalyst was proven to prolong the lifetime of the photocatalytic membrane and retard membrane fouling to the maximum extent. PAN/TiO₂/CNT membrane has displayed 100% MB rejection for the first 8 h of operation. Both, PAN/TiO₂/CNT and PAN/TiO₂/CNT-PVA maintained their membrane performances and did not show major flux decline even after five recycling uses. The incorporation of TiO₂/CNTs on PAN nanofibers has resulted in a durable photocatalytic membrane for the effective removal of dye waste using a cross-flow membrane reactor.