High efficient 3D solar interfacial evaporator: Achieved by the synergy of simple material and structure

Solar steam generation has attracted tremendous attention because of severe freshwater scarcity and people's high degree of recognition of solar energy. However, photothermal conversion efficiency and thermal management capability are still the key factors restricting solar steam generation. Here, we prepared an efficient 3D solar interfacial evaporator via material selection and simple structural design. The microstructure shows that the air-laid paper is made up of two layers of unidirectional fibers of different shapes, which can provide efficient water transportation and strong photon capture capability. As for macrostructure, the 3D arched evaporator can greatly reduce heat conduction loss by reducing the contact area between the evaporator and bulk water and achieve high efficiency of solar utilization throughout the day. Finally, the 3D arched structure is beneficial for steam diffusion. As a result, the evaporator showed excellent photothermal conversion efficiency and thermal management capability by the synergy of microstructure and macrostructure. It has achieved an evaporation rate of 2.0 kg m−2 h−1 under 1 sun illumination with an energy utilization efficiency of 93.5%, and the efficiency remained above 90% when the incidence angle changed from 90° to 45°, which can produce clean water from seawater and contaminated water. •An efficient 3D solar interfacial evaporator was prepared via material selection and simple structure design.•The evaporator achieved an evaporation rate of 2.0 kg m−2 h−1 under 1 sun with an energy utilization efficiency of 93.5%.•The unique microstructure of the modified paper makes the evaporator efficient in water transfer and solar absorption.•The macrostructure of the evaporator can reduce heat loss greatly and result in excellent thermal management.