Solvent-free fabrication of photothermal polypyrrole-coated sulfur particles for solar steam generation

Abstract

The use of solar heat to produce steam holds great potential in terms of solving drinkable freshwater scarcity worldwide. However, the fabrication of low-cost, large-scale photothermal materials remains difficult; existing multi-step processes use toxic solvents. Here, a solvent-free and facile synthetic process is presented: we coat sulfur (S) with polypyrrole (PPY), then use PPY-coated S (S-PPY) as a photothermal layer for solar steam generation. We demonstrate an excellent solar steam evaporation rate (2.13 kg m-2h−1 at 1 Sun light intensity; efficiency 88.92 %). The use of inexpensive and abundant S as a substrate for PPY photothermal composites will find many energy-conversion applications as welll as water purification and desalination via solar steam generation.