Cuprous oxide (Cu2O) nanoparticles in nanofiltration membrane with enhanced separation performance and anti-fouling properties

Cuprous oxide nanoparticles (Cu2O) were synthesized by electrochemical method and as an add-on to construct polyethersulfone (PES) nanofiltration (NF) membranes. Field emission scanning electron microscopy (FESEM), 3D surface images, X-ray diffraction (XRD) analysis, and Fourier transform infrared (FTIR) spectroscopy were utilized to indicate membranes and nanoparticles. Membranes were evaluated by tests of water content, porosity, contact angle, salt rejection, water flux and average pore size measurements. The results show the enhancement of surface hydrophilicity by the addition of Cu2O nanoparticles. The highest unalloyed water flux was obtained by membrane, including 0.05 wt% Cu2O nanoparticles, and the highest rejection was revealed by a membrane containing 2 wt% Cu2O nanoparticles. The Na2SO4 rejection reached 66.94%, which was significantly higher than the bare PES membrane. This performance may be owing to increased Na2SO4 adsorption sites. The heavy metals rejection of CrSO4, Pb(NO3)(2), and Cu (NO3)(2) increased 79.38%, 85.08%, and 81% for the M5 membrane, respectively, while it was 45%, 46%, and 49% for bare membrane, respectively. Furthermore, the flux of unalloyed water increased from 9.78 L/m(2)center dot h on the pure PES membrane to 36.78 L/m(2)center dot h on the M1 membrane. The decrease of surface roughness and also the increase of hydrophilic groups improved the antifouling properties of the membranes.

Automated summary

Cuprous oxide nanoparticles were synthesized and used as an additive to fabricate polyethersulfone nanofiltration membranes. The membranes exhibited improved hydrophilicity and higher rejection rates for Na2SO4 and heavy metals compared to the bare PES membrane. The addition of Cu2O nanoparticles also resulted in an increase in water flux and improved antifouling properties.