A simple, flexible, and porous polypyrrole-wax gourd evaporator with excellent light absorption for efficient solar steam generation

Summary Solar interfacial water evaporation is considered as a potential green technology to solve the global shortage of freshwater resources. However, it is still an arduous task to develop a low-cost and efficient solar evaporator with a simple preparation method. Herein, a simple, flexible, and porous polypyrrole-wax gourd (PPy-wax gourd) biomass evaporator was reported for solar evaporation enhancement. Wax gourd had the advantages such as superhydrophilic wettability, massive microporous channels, and easy planting. PPy was a kind of black polymer with excellent light absorption ability, which greatly improved the light absorption of the PPy-wax gourd evaporator within a full spectrum of solar irradiance (300-2500 nm). The PPy-wax gourd evaporator prepared by the perfect combination of wax gourd and polypyrrole realized a superior vapor generation ability (1.57 kg m −2 hours −1 ) with a photothermal conversion efficiency of 77.3% under 1 solar intensity, which was better than some other biomass evaporators developed so far. In addition, the PPy-wax gourd evaporator also exhibited remarkable stability and durability under long-term recycling utilization and harsh environments. Importantly, the PPy-wax gourd evaporator demonstrated prominent wastewater purification capacity and desalination performance for dye wastewater and simulated seawater treatment. Based on these results, this work would offer a new strategy for developing novel biomass thermal evaporators the clean water production.