PDMS@MoS₂/GO Janus Membrane-Based Solar-Driven Interfacial Evaporation for High-Yield Water Purification

Solar-thermal interfacial membrane evaporation (STIME) technology has emerged as a highly efficient method for seawater desalination. However, its application in heavy metal wastewater treatment remains challenging and requires further research to develop effective solutions. In this study, we present a Janus membrane, poly(dimethylsiloxane) (PDMS)@MoS₂/GO (P@MS/G), which integrates solar-driven water evaporation with the simultaneous adsorption of heavy metal ions, specifically Cu²⁺ and Pb²⁺ (X²⁺). The membrane exhibits an evaporation rate of 2.07 kg m^-2 h^-1 and a solar-to-vapor efficiency of 90.16% under 1 sun irradiation. The functional groups of graphene oxide (GO) impart exceptional adsorption capabilities for heavy metal ions to the composite material. The adsorption mechanism is characterized as an endothermic process. STIME enhances the interface temperature and local ion concentration, thereby promoting the adsorption of X²⁺. Further insight into the adsorption mechanism is provided through molecular dynamics (MD) simulations. As the simulation temperature increases, the diffusion coefficients of both heavy metal ions and water molecules increase, leading to an improved adsorption capacity and enhanced evaporation efficiency. These findings contribute valuable insights into the development of sustainable and effective water purification technologies, offering a promising approach to accessible, clean water solutions on a global scale.