Rapid preparation of Janus biomass evaporator by dielectric barrier discharge plasma for high-efficiency desalination and wastewater purification

The conversion of biomass into desalination evaporators for the fresh water production has been proven a promising green strategy for the replenishment of fresh water resources. However, the primary challenges for the widespread application of such technologies are time-consuming, complex preparation processes and the stability of the evaporation interface. Herein, a novel biomass based hydrophilic/hydrophobic Janus structure plasma carbonized film material (JPCF) was prepared by dielectric barrier discharge (DBD) plasma. The preparation involved a short treatment time of 12 min after applying crylamide (AM) solution and sodium metasilicate nonahydrate (SMN) solution to different sides of a poplar chip. The evaporation rate of the prepared JPCF can reach 1.77 kg m−2h−1 in pure water and 1.75 kg m−2h−1 in 3.5 wt% NaCl solution under 1 solar irradiation. During a continuous evaporation of 14 h, the evaporation performance remained stable and no obvious salt accumulation appeared at the evaporation interface. More importantly, the JPCF showed an excellent purification ability to wastewater containing dye, oil, acids and alkalis. These key properties make the biomass-based Janus evaporator prepared by DBD plasma have a wide range of applications in desalination and wastewater treatment.