Magnetic recyclable Fe3O4@Ti3C2TX nanoparticles for high-efficiency solar membrane distillation

Over the last few years, solar energy has emerged as a sustainable energy which can replace traditional fossil energy sources. Solar evaporation systems are very dependent on the concentration of light-absorbing particles. However, solar evaporation systems have low water production rates and the used nanofluids usually causes secondary pollution. These problems seriously limit the wide application of solar evaporation techniques. In this work, we established a novel solar direct contact membrane distillation system combining Fe3O4@MXene light absorbing particles (Fe3O4 nanoparticles modified with Ti3C2Tx MXene) and membrane distillation, which could improve the water production rates and the used light-absorbing nanoparticles were easily separated by magnetic field for reuse. In this system, Fe3O4@MXene acts as an efficient photothermal conversion particle that heats the feedwater for membrane distillation by absorbing sunlight, eliminating the additional energy input. The test results showed that the water production rate of this system was superior to that of most published solar membrane distillation systems, which the flux could reach 2.26 kg/m2/h, and the nanoparticles could be almost completely recycled. The work not only provides a useful method of desalination using solar energy and membrane distillation, but also to reduce the materials consumption and overall operating cost.