Improved properties and salt rejection of polysulfone membrane by incorporation of hydrophilic cobalt-doped ZnO nanoparticles

In this study, the nanoparticles (NPs) of ZnO and Co²⁺ ions doped ZnO (doped ZnO) were incorporated into a matrix of polysulfone (PSf) membranes to enhance their surface properties prepared using a simple wet phase inversion technique. The hybrid PSf membranes were fabricated with 0.5 wt. % of ZnO and doped ZnO NPs. These membranes were characterized using XRD, TGA, FESEM-EDX, and salt rejection performance. The hydrophilicity of PSf membranes was improved by adding of ZnO and doped ZnO NPs which showed a decrease in contact angle values from 82° to 62° with an increased flux with water. Among the prepared membranes, doped ZnO NPs showed the highest salt rejection for both sodium chloride (NaCl) and sodium sulfate (Na₂SO₄) compared to pure PSf and PSf with ZnO NPs which confirm the improvement contact angle and water permeability. Overall, the results of this study showed that embedding a small amount of Co²⁺ ions doped ZnO NPs with PSf has significant potential to be applied in industrial-scale membrane applications.