Sustainable and low-cost cellulose aerogel-based absorber for solar steam generation

Abstract

Solar steam generation is a promising technology for sustainable seawater desalination. However, its practical application is hindered by the low water evaporation rate and the high cost of materials. Carbon aerogels have demonstrated superior properties for clean water production through solar steam generation, but the complex and time-consuming preparation process inhibits their development and applications. In this study, high-performance solar steam absorbers based on cellulose-derived carbon aerogels were prepared from paper and waste paper using a simple green method. The fabricated carbon aerogels have a typical microporous structure (pore diameter: 20–250 µm), super-hydrophilic properties, good mechanical properties and efficient solar light absorption (∼96 %), which make them ideal for application in solar steam generation. Three different configurations based on cellulose and carbon aerogels were fabricated (bulk absorber, double-layer absorbers and ink-based absorber) to achieve the best design with high efficiency for steam generation. The surface temperature of the bulk absorber and dry double-layer absorbercan achieve 100 °C under 1 kWm−2irradiation. Among all configurations, the double-layer absorbers represented the highest efficiencies, 90.4 % for paper and 84.3 % for waste paper, under 1 kWm−2 irradiation, which are higher than most reported results. According to the results, the sustainable cellulose-based double-layer absorbers were promising materials for efficient solar steam generation due to their high hydrophilicity, high sunlight absorption, open porous structure, non-toxicity, biodegradability, availability and low cost.