Recyclable Solar Evaporator Based on 0d Hollow Glass Microspheres for Water Purification and Desalination

Abstract

Solar-driven interfacial steam generation (SISG) has attracted much more attention for its significant potential in water purification and desalination. Herein, we report the fabrication of a novel photothermal material (MHGM/Fe3O4/TiO2–Ag/PPy) by coating Fe3O4, TiO2 & Ag, and fluorosilane doped polypyrrole on (3-Aminopropyl)triethoxysilane (APTES) modified HGM, respectively, and a certain amount of such hollow microspheres self-float on the water surface as a solar evaporator for efficient SISG. Based on its unique 0D hollow structure with low thermal conductivity (0.0455 W m–1 k–1), strong light absorption (about 95%) and hydrophobic wettability, as well as the self-floating ability of MHGM/Fe3O4/TiO2–Ag/PPy and the gap between the microspheres provides the channels for water transportation, the solar evaporator of MHGM/Fe3O4/TiO2–Ag/PPy shows a high water evaporation rate of 1.5516 kg m–2 h−1 under 1 kW m–2 solar irradiation and excellent salt resistance. Moreover, the evaporator possesses efficient photodegradation and antibacterial performance. Most importantly, the evaporator exhibits magnetic property and can be magnetically recovered. This solar evaporator composed of 0D recyclable hollow microspheres is reported for the first time and shows great potential for practical applications, including seawater desalination, sterilization and synergistic water purification during freshwater production.

Keywords: Solar-driven interfacial steam generation, hollow glass microspheres, salt resistance, Desalination, Water purification