Equilibrium and optimization of water-heat transfer in natural cellulose-based hybrid hydrogel for efficient solar desalination

Abstract

Solar interfacial evaporation for seawater desalination and wastewater purification is considered a promising strategy to alleviate the water scarcity crisis. Currently, the ways to improve evaporators usually revolve around iteration of photothermal materials (enhancing heat generation) or macrostructural remodeling (altering water transport rate), but these means have limitations and do not achieve simultaneous and precise regulation of water-heat utilization. Herein, a simple hydrothermal method is used to synthesize natural cellulose-based hybridized hydrogels, exhibiting a high evaporation efficiency (97.67%) and a full range of water purification capabilities, including antimicrobial, anti-salt accumulation, and degradation of organic dyes. Significantly, the enhancement mechanism of the energy-mass utilization of this evaporator can be explained from two aspects. Firstly, the hybridization of natural cellulose and inorganic carbon materials can supplement a large number of hydrophilic functional groups, thus fully activating the water molecules and reducing the evaporation energy consumption. Furthermore, the COMSOL simulation is used to clarify the distribution of water and heat, and by adjusting the height of the hydrogel, the balance of water-heat transfer is cleverly achieved with the maximization of energy utilization. Overall, the optimization idea of water-heat transfer provides a new direction for future evaporator design and a fresh opportunity for the improvement of energy-mass management model.