Graphene oxide laminates intercalated with Prussian blue nanocube as a photo-Fenton self-cleaning membrane for enhanced water purification

Abstract

The separation performance of nano-laminated graphene oxide membranes is heavily decided by their nanoscale structures. Antifouling properties of the membrane have an influence on membrane performance significantly beside tuning 2D GO interlayer spacing. Herein, we intercalated a photo-Fenton catalytic Prussian blue nanocubic into graphene oxide laminates to fabricate a GO/PB membrane through a simple vacuum filtration process, the 2D nano-channel was characterized and simulated by SEM and Molecular dynamics (MD) simulations. The PB nanocubic can not only serve as nano pacers to prevent the restacking of GO nanosheets and adjust 2D nanochannels, but endow the membrane with photo-Fenton self-cleaning function. As a consequence, the GO/PB membrane presents a high separation efficiency (∼100% dye rejection), and the water permeability is nearly 2 times higher than that of the pristine GO membrane under synergistic separation and photo-Fenton self-cleaning processes. Scavenging experiments and characterization results indicated the active species of h+ and ·OH play a major role in the degradation process. In addition, the GO/PB membrane exhibited outstanding antifouling performance and reusability, retaining high dye removal efficiency (>95%) and high water-permeability (∼132.7 Lm−2h−1bar−1) after three separation cycles with photo-Fenton treatment in each cycle. Moreover, full-scale zebrafish toxicology assays have indicated that the dye stock solution exerted significant toxic effects on zebrafish with increased mortality and malformations compared to the control, while the filtrate induced negligible toxic effects. Overall, this work reveals the dual roles of PB as nanospacers and photo-Fenton catalytic nano-filler, providing a new concept for the development of hybrid nanolaminated membranes for water purification and textile wastewater treatment.