Nanofiber Membranes Comprising Mn+1AXn Phases as the Basis of Durable Photothermal Evaporators in Extreme Environments

Solar-driven interfacial evaporation (SDIE) has emerged as an efficient approach for sustainable freshwater generation, with current research predominantly focusing on photothermal materials and evaporator configurations. However, there is less attention from a practical engineering perspective for SDIE applications in extreme environments or industrial requirements, such as strong acids, alkalis, and high-salinity wastewater. Herein, we propose a one-dimensional (1D) MAX phase-based photothermal evaporator that combines exceptional solar-thermal conversion efficiency with high chemical stability, enabling efficient solar energy conversion to produce freshwater in various extreme environments. The engineered Ti₂AlSnC nanofiber membrane evaporator demonstrates a continuous 30-day operation in concentrated acids (pH < 1) while maintaining a stable evaporation rate of 2.8 kg m^–2 h^–1. Furthermore, the integrated Joule heating module enables all-day operation under low-light conditions with a minimal energy input (≤3 V). The development of such a material establishes a promising strategy for more practical and durable water treatment solutions to harsh environments.