High Efficiency Double-Layer MwcntsHpps Photothermal Paper for Desalination and Sea Salt Collection

Solar energy is sustainable and environment-friendly, solar driven interface evaporation technology has been identified as a promising method to reduce the global water crisis. However, how to design an ideal structure of photothermal conversion evaporation device is particularly difficult. In this paper, HPPS paper with loose structure and appropriate water transmission performance was designed as the based-material and MWCNTs layer with excellent photothermal conversion performance was deposited on the surface to realize the high-efficiency solar driven evaporation performance. Under tail swabbing mode, the cold evaporation surface was existed on the bottom of HPPS layer, the energy generated by MWCNTs layer was transmitted to the cold evaporation surface, the maximum water evaporation rate of 1.23 L/m 2 ·h was achieved. By introducing Ethyl cellulose (EC) to adjust the water transmission performance of HPPS layer, a cold evaporation surface with large specific surface area was obtained, which caused the increase of water evaporation rate. In addition, there was continuous micro water circulation inside HPPS layer, which promoted the diffusion of high concentration brine caused by water evaporation on the top surface to the lower layer for crystallization and precipitation, so as to realize the dual output of drinking water and sea salt