Self-floating Bi2S3/poly (vinylidene fluoride) composites on polyurethane sponges for efficient solar water purification

Solar water purification (SWP) has been considered as one of the most sustainable techniques to address clean water shortage problem. Although significant strategies have been proposed to explore portable SWP device, many challenges, such as complicated fabrication, high costs and poor practicability, still remain to be solved. Here, a facilely and integrally designed Bi2S3/poly (vinylidene fluoride) (BP) composites based on polyurethane (PU) Sponges (PBP composites) is reported. The PBP composites consist of integrated structures, in which multiple internal reflections guarantee sufficient harvest of incident light and tip thermal effects of chrysanthemum-like Bi2S3 ensure efficient solar thermal conversion, and porous BP endows it with adequate water supply, thus exhibiting a high water evaporation rate of 1.66 kg m(-2) h(-1) and a solar thermal efficiency of 92.9% under one sun irradiation. This bionic optical design and heat management design may provide a new inspiration to utilize solar energy in water purification and other related applications.