Multifunctional and sustainable chitosan-based interfacial materials for effective water evaporation, desalination, and wastewater purification: A review

Freshwater scarcity, energy shortage, and water pollution are the three most serious threats to sustainable development. Solar interfacial evaporation technologies have shown great potential for harvesting green solar energy for freshwater production, seawater desalination, and wastewater treatment. Chitosan-based solar interfacial evaporators (CS-SIEs) can realize efficient water evaporation due to their unique properties such as lower vaporization enthalpy, salt resistance, antibacterial properties, and thermal insulation. This review paper summarizes four types of CS-SIEs platforms, including hydrogels, aerogels, sponges and membranes (films). Five types of modified materials used in CS-SIEs are emphasized and summarized, including carbonized chitosan, carbonaceous materials, semiconductors, polymeric and multiple materials. In addition, diversified applications of CS-SIEs are highlighted in water evaporation, desalination, and wastewater purification. Finally, challenges and future prospects are presented to reveal bottlenecks in the applications of CS-SIEs for sustainable water and environmental pollution control engineering. This article aims to provide an overview of the latest development in CS-SIEs and inspire further exploration of novel CS-SIEs with higher efficiency and more versatility to address the limitations of their current research and promote their early industrialization.