High-efficiency, thermal stable, and self-floating silver nanowires/Ti3C2Tx MXene/aramid nanofibers composite aerogel for photothermal water evaporation and antibacterial application

Abstract

Interfacial solar steam generation shows great potential as a technology for seawater desalination. However, there are still considerable challenges in manufacturing photothermal evaporators with ultra-low thermal conductivity, mechanical robustness, and high-temperature resistance. Herein, we report Ag nanowires/Ti3C2Tx MXene/aramid nanofibers (Ag/Ti3C2Tx/ANFs) composite aerogel photothermal evaporators with internal three-dimensional (3D) micropores and a layered structure. The ANFs porous frame, with excellent mechanical properties and low thermal conductivity, allows abundant water transmission channels and reduces heat loss. Ti3C2Tx MXene and Ag NWs, known for their broadband absorption capability and antibacterial properties, enhance photothermal conversion efficiency. The Ag/Ti3C2Tx/ANFs composite aerogel distinguishes itself with a wide compression range (2 %∼60 %), remarkable light absorption capacity (96 %), and low thermal conductivity (0.49 W/mK), excellent thermal stability ensures the composite aerogel could withstand a wide temperature range from ∼500 °C to ∼196 °C. As expected, under one sun illumination, the Ag/Ti3C2Tx/ANFs composite aerogel presents a high evaporation rate of 2.21 kg m-2h−1 with an energy efficiency of 92 %. In addition, this evaporator composite aerogel exhibits outstanding and efficient salt tolerance, desalination, antibacterial properties, and heavy-metal ion wastewater purification capabilities. The unique evaporator structure presented here offers a new perspective for the structural design of next-generation, high-efficiency solar evaporators.