3D Graphene Composite Foams for Efficient and Stable Solar Desalination of High‐Salinity Brine

Abstract

Solar‐driven interfacial evaporation (SIE) is a promising desalination technology that utilizes solar energy and seawater. However, most SIE systems are limited by high cost, complex fabrication, and low salt tolerance. Herein, a simple method is presented for preparing a 3D graphene/carbon nanotubes/polypyrrole foam (GCPF) evaporator that exhibits high evaporation efficiency, excellent mechanical performance, and stable solar desalination of high‐salinity brine. The excellent processability of melamine foam enables the easy preparation of the 3D GCPF, which exhibits an enhanced evaporation rate of 4.012 kg m−2 h−1 and a photothermal conversion efficiency of 97.8% under one sun irradiation. Compared with the 2D sample, the GCPF‐3 evaporator utilizes solar energy more efficiently and maintains higher evaporation performance even when the light angle changes. Moreover, the 3D GCPF shows remarkable salt tolerance and durability, achieving a stable evaporation rate of 4.005 kg m−2 h−1 for 30 h with a salinity of 25 wt%, which is the best‐reported result among solar desalination systems. This work provides new insights into the design of 3D graphene composite foams and demonstrates their potential applications in continuous solar desalination.