Hierarchical Directed Self-Assembly of Carbon Nanotubes for Textile-Based Solar-Driven Clean Water Generation and Integrated Photochemical Degradation

Solar-driven water evaporation has emerged as a promising solution to the freshwater shortage crisis in modern industry. However, significant challenges remain in developing water evaporation materials that combine high evaporation efficiency with salt resistance, cost-effectiveness, scalability, and portability. Herein, we propose a textile-based solar-driven water evaporator prepared by the hierarchical directed self-assembly of carbon nanotubes (CNTs), further incorporating visible-light-driven photocatalytic nanoparticles for pollution degradation. The CNTs were aligned along the fiber directions during the hierarchical directed self-assembly, thereby forming dense nanochannels. The as-prepared CNT-coated fabric proves a synergistic impact based on the confined effect of the interfacial nanochannels and capillary force between the fibers as well as its excellent photothermal conversion capability, resulting in efficient water evaporation. The results demonstrate a rapid evaporation rate of 1.51 kg m^-2 h^-1 and energy efficiency of 83.9% under 1.0 sun irradiation, as well as high-yield clean water generation in high salinity seawaters and dye wastewaters. Incorporating visible-light-driven photocatalytic nanoparticles, the coated fabric enabled the dye solutions of 10 mg mL^-1 methylene blue (MB) and methylene orange (MO) to degrade almost completely within 1 h. This work offers a facile strategy for constructing an efficient textile-based water evaporator for practical large-scale clean water treatment.