Bioinspired, Sustainable, High-Efficiency Solar Evaporators for Sewage Purification

To alleviate the severe water crisis, an interfacial solar evaporator provides a promising method to produce freshwater. Although many superior solar evaporators present high evaporation rates by reducing the water evaporation enthalpy, adapting sustainable materials to construct high-efficiency solar evaporators remains challenging. Herein, inspired by the corncob pith's structure and functional groups, interconnected porous cellulose hydrogel is proposed by crosslinking sustainable hydroxypropyl cellulose. Benefiting from the porous structure and abundant hydroxy group, the corncob pith/carbon nanotubes (CNTs) and cellulose hydrogel/CNTs evaporators show a low evaporation enthalpy of 880.5 ± 42.1 and 1280.7 ± 57.8 J g⁻¹ due to the reduced hydrogen bond numbers between water molecules and enable evaporation rates of 3.06 and 2.56 kg m⁻² h⁻¹, respectively. Moreover, the evaporators present superior purification performance for seawater and sewage, and show excellent anti-biological fouling properties under light irradiation. It is anticipated that the bionic strategy would provide an in-depth understanding of designing next-generation sustainable solar evaporators in the framework of the dual-carbon concept.