Low-cost and scalable carbon bread used as an efficient solar steam generator with high performance for water desalination and purification.

Solar steam generation has been considered as a promising method for water desalination and purification. Achieving a simple, scalable and cost-effective method to fabricate solar-thermal materials with high performance is the key for its widespread application. Herein, we demonstrate high performance "carbon bread" as a solar steam generator via a facile one-pot baking process, which can be carried out in most household kitchens in our daily life without high-temperature carbonization. The carbon bread could achieve ∼85.9% conversion efficiency under 1 sun illumination and ∼81.7% efficiency even under 0.25 sun. The highly efficient solar steam generation performance benefits from the unique structure and properties of carbon bread: efficient and broadband light absorption, 3D interconnected hierarchical pores, excellent hydrophilicity and thermal insulation. This scalable material could generate fresh drinkable water from seawater and wastewater under ambient conditions. The successful demonstration of this simple and easily accessible carbon bread material could inspire the development of solar-driven water evaporators derived from low cost and commercially available raw chemicals through a simple manufacturing process for practical water desalination and purification on a large scale.