Multifunctional MoS2/CNTs/Chitosan Hybrid Hydrogel Sponge for Efficient Solar-Driven Seawater Desalination and Wastewater Purification.

Solar-driven interfacial evaporation provides an eco-friendly and potentially effective method to addressing global freshwater shortages. However, designing multifunctional solar evaporators capable of high-efficiency evaporation and effective wastewater purification remaining significant technical challenges. Herein, we have fabricated a scalable and self-cleaning solar evaporator (MoS2/CNTs/CS@MS, abbreviated as MCCM) via strategic integration of MoS2, chitosan (CS), carbon nanotubes (CNTs), and melamine sponge (MS) into a hybrid materials system. The chitosan-modified melamine sponge immobilized MoS2/CNTs through robust electrostatic interactions, while simultaneously constructing hydrophilic pathways to facilitate mass and water transport. With a remarkable evaporation rate of 1.82 kg·m-2·h-1 (about 7.9 times that of natural evaporation, 0.23 kg·m-2·h-1), the MCCM evaporator also exhibited exceptional salt tolerance in 20 wt% NaCl brine, owing to synergistic capillary forces, porous structure, and hydrophilicity. MoS2/CNTs in MCCM improved light absorption property and promoted photoinduced charge separation, achieving 98.27 % of CR degradation under solar irradiation. With 22.45 kg·m-2 freshwater output in 9 h of natural solar light, desalinated water by MCCM not only meets WHO and EPA drinking water standards, but also effectively supports plant germination. By integrating solar evaporation with photocatalysis, this MCCM offers a viable solution for sustainable water purification in marine and industrial settings.