Effect of phase disparity of MoS2 nanosheets on the performance of PES membranes for dual industrial oil-in-water emulsion separation and dyes adsorption

Abstract

Water shortage is a global challenge due to increased demand and hence, reliable wastewater treatment avenues must be created to solve this problem. In this work, we report about the fabrication of dual performance polyethersulfone (PES) membranes modified with molybdenum disulfide (MoS2) nanosheets of different phases for wastewater remediation. We optimised process parameters to obtain large area, defect free membrane sheets. Comprehensive characterization revealed the phase disparity of MoS2, and changes introduced in the modified PES membranes. Blending MoS2 with PES membranes enhanced the mechanical properties as well as water uptake differently. The optimum PES membrane was modified with 0.2 wt% of 70% 1 T/2 H MoS2 and possessed superior pure water permeance of 778 kg/m2.h.bar. It also showed superior performance towards oil removal with rejection efficiency of 99% for 1 g/L oil concentration and it revealed excellent antifouling properties. The optimum membrane showed appreciable performance in organic dye rejection, even though it was outpaced by the 0.5 wt% of 70% 1 T/2 H MoS2 modified PES with a dye rejection of 98% towards methylene blue and 92% towards Rhodamine B. This work revealed that the phase of MoS2 strongly influences the structure and performance of the resultant PES-based nanocomposite membranes in ultrafiltration applications.