Three-Dimensionally Structured Polypyrrole-Coated <i>Setaria viridis</i> Spike Composites for Efficient Solar Steam Generation

Abstract

Solar-driven steam generation is a promising technology for the production of freshwater from seawater and polluted water. High water evaporation rates have been achieved via the interfacial heating scheme; however, they are still limited to meet the increasing need for freshwater due to the restricted evaporation area of two-dimensionally (2D) geometrical planar photothermal membranes. Herein, a three-dimensionally (3D) structured solar evaporator is prepared via coating photothermal polypyrrole (PPy) on the spike of <i>Setaria viridis</i>(<i>S. viridis</i>) for highly efficient evaporation. Due to the enlarged evaporation area and open structure for vapor dissipation, the PPy-coated <i>S. viridis</i> spike solar evaporator shows a high water evaporation rate of 3.72 kg m^-2 h^-1 under one sun illumination. The 3D solar evaporator also demonstrates good durability and anti-salt-clogging performance for real-life applications. Furthermore, we show that the 3D solar evaporator demonstrates effective decontamination of saline water, dye-contaminated water, and corrosive water. This work can inspire new paradigms toward developing high-performance solar steaming technologies for effective water purification to address the worldwide crisis of freshwater shortage.