A high-efficiency solar desalination biomass material prepared by DBD plasma

Abstract

Biomass materials for interfacial evaporation with solar energy have obvious advantages and potentials in the field of desalination. In this work, plasma technology is first used to prepare biomass materials for seawater desalination. The plasma carbonized film (PCF) is obtained from poplar chips treated by dielectric barrier discharge (DBD) plasma. The whole preparation process can be quickly achieved in one step without any chemical reagent or carrier gas. After DBD treatment, the original water channels of the xylem are preserved ensuring efficient water transport and high salt resistance. The hydrophobic nature of the evaporator surface makes it self-floating. Under sunlight irradiation, photons are captured by the black PCF surface converting solar energy into heat energy, and fresh water can be continuously and stably obtained from salt water. The evaporation rate under one sunlight by PCF in water and 3.5 wt% NaCl solution can reach 1.70 kg m−2 h−1, and 1.63 kg m−2 h−1, respectively. PCF has abundant micron-sized holes and low-distortion channels making the material form a 3D interconnection structure. Therefore, PCF has a solar-steam conversion efficiency as high as 91%. Besides, the tolerance test shows that PCF can still maintain a high evaporation rate and self-clean after long-term work.