Damage‐Free Solar Dewatering of Micro‐Algal Concentrates via Multifunctional Hierarchical Porous Graphene

Abstract A damage‐free dewatering method, without centrifugation, mechanical squeezing, and solar irradiation, is important for separating solids from pure water and can be used for the production of biomass‐derived renewable fine chemicals, fertilizers, and fuels in biotechnological applications. Herein a damage‐free steam generator constructed by a single sheet of nitrogen‐doped nanoporous graphene and nitrogen‐doped porous graphene foam as hierarchical structures is reported. The multifunctional hierarchical graphene steam generator has a high water evaporation rate (1.54 kg m⁻² h⁻¹) accompanied by a high energy conversion efficiency (82.2%). Furthermore, it exhibits excellent persistence in dewatering performance over multiple uses, unlike the graphene foam that shows marked reduction in performance after several reuses. Therefore, the multifunctional hierarchical graphene steam generator is a cost‐effective material for accelerating both the harvesting of biomass concentrates and the production of pure water.