Highly Efficient Solar Steam Generation and Desalination through Gourd‐Flesh Templated Polypyrrole Composite

Solar steam generation (SSG) is regarded as a promising technique due to its potential in seawater desalination. Photothermal conversion materials derived from biomass are good evaporators for SSG because of their sustainability and high efficiency. Herein, 3D‐cylindrical‐structured composite materials based on gourd flesh and polypyrrole (GPPY) are designed and used for high efficient SSG. The polypyrrole layer is deposited on the gourd flesh to provide broad optical absorption ability and high photothermal conversion efficiency. In addition, gourd flesh with porous structure can act as thermal insulators, confine the generated heat within the evaporative surface, and facilitate the efficient transport of water to the photothermally active area. Based on these characteristics of the composite, the evaporator made of GPPY can achieve a high evaporation rate of (1.63 kg m −2 h −1 ), and a superior photothermal conversion efficiency 95.8% under 1 solar irradiation (1 kW m −2 ). The GPPY can be expected to be a practical photothermal conversion material for commercial SSG based on its high efficiency and sustainability.