Effect and regulation mechanism of oxidation degrees on the O–MoS2 structure and separation performance of nanofiltration membrane

Abstract Oxidized molybdenum disulfide (O–MoS2) as a two-dimensional (2D) functional nanosheets material, has been used to fabricate high separation performance nanofiltration (NF) membranes for water treatment. However, the effect and regulation mechanism of the degree of oxidation on structure and separation performance of O–MoS2 modified NF membrane has not yet been fully understood. In this work, O–MoS2 with different oxidation degrees was synthesized by adjusting the oxidation time and KMnO4 oxidant content via Hummers’ method. The results demonstrated that the O–MoS2 synthesized under with an oxidation time of 3 h and MoS2:KMnO4 ratio of 1:2 had excellent stability under acidic, neutral and alkaline conditions. The pure water flux increased 2.5 times and the Na2SO4 salt rejection increased to 97.6% with this O–MoS2 incorporation compared to the control membrane. The influence of different oxidation degrees on the performance of O–MoS2 is a breakthrough finding of this work to provide a theoretical basis for the application of O–MoS2 in the field of membrane separations.