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. The PPy‐wax gourd evaporator achieved excellent water evaporation ability and fascinating evaporation efficiency. Wax gourd‐based biomass materials are desirable for solar steam generation. Durability under harsh working environments. Highly effective removal for salts and organic dyes.