Biomimetic Design of Macroporous 3D Truss Materials for Efficient Interfacial Solar Steam Generation

Interfacial solar steam generation (ISSG) utilizing local heating technology for evaporation at the water-to-steam interface is drawing great attention because of its high efficiency of solar-thermal conversion for a sustainable and eco-friendly drinking water regeneration process. Here, inspired by the structure of penguin feathers and polar bear hairs that both have macropores to trap air for thermal insulation, we report a bionic solar evaporator (BSE) with macroporous skeleton for partial thermal management and macro patulous channels for abundant water transportation and rapid steam extraction. Meanwhile, the 3D hierarchical isotropic truss structures can induce multiple light reflections to enable omnidirectional light absorption, and bimodal pores facilitate ion diffusion to suppress salt deposits. This BSE exhibits an evaporation rate of 2.3 kg m^-2 h^-1 and efficiency of 93% under 1 sun. The multiple advantages of high efficiency and salt resistance make BSE available for future practical sewage purification and desalination applications.