A novel chitosan/Chinese ink composite aerogels: Preparation and application for solar steam generators

Abstract

The use of carbon-based materials as photothermal components in solar steam generators faces challenges such as complex preparation processes and pollution during carbonization. To overcome these issues, a one-pot green immersion preparation process was developed, incorporating carbon nanoparticles from traditional Chinese ink (CI) with photothermal properties into chitosan (CS) aerogels for steam generation under sunlight. The resulting three-dimensional sponge-like porous structure features oriented two-dimensional water transport channels, enabling rapid water pumping and multiple light path refractions within the aerogel. The carbon nanoparticles in CI were shown to disperse uniformly in the CS matrix. This lightweight aerogel, characterized by low thermal conductivity, achieves an evaporation rate of 2.13 kg m⁻² h⁻¹ under 1.0 sunlight, demonstrating high efficiency in treating seawater with high salinity, strong acid/base solutions, and dye-containing wastewater. The aerogel minimizes heat loss during solar evaporation and achieves effective self-desalination during the desalination process. Utilizing simple and green CI as a photothermal material offers a sustainable and cost-effective approach to address global water and energy shortages.