Engineering Hierarchically Structured Nanofibrous Aerogels for Highly Efficient Solar Vapor Generation and Desalination

Electrospun nanofiber-based evaporators have emerged as advanced candidates in the field of solar-driven desalination, stemming from their favorable flexibility, high porosity, and ease of functionalization. Herein, a novel and facile template-free method is developed for preparing polypyrrole nanorod-adorned nanofibrous aerogels, which are reliable and efficient for solar desalination. More notably, polypyrrole plays a crucial cross-linking role in promoting structural stability, avoiding the use of harmful cross-linkers. The presence of polypyrrole nanorods has further augmented light absorption, decreased vaporization enthalpy, and enhanced evaporation performance with an optimal evaporation rate of 2.37 kg m–2 h–1. In addition, the hierarchically structured nanofibrous aerogel enables durable and stable evaporation out of high-concentration brines, superior to most of the electrospun nanofiber-based evaporators. Taking advantage of the excellent photothermal property, the aerogel assembled with a thermoelectric generator can obtain 58.59 mV voltage output under one sun illumination. The exceptional aerogel holds great potential in harnessing solar energy to address the issue of water and energy scarcity.