A versatile solar-powered vapor generating membrane for multi-media purification

Water evaporation driven by solar energy is an efficient, renewable, and environmentally friendly method to purify polluted or saline water. However, current solar-powered evaporation systems generally suffer from the poor stability, high materials cost, and complex fabrication processes. In this work, an inexpensive and versatile photothermal membrane (PTM) is prepared with basalt-fibers, which are prepared from natural basalt and synthesized by fiber forming and annealing. Owing to the special chemical composition and physical structure, the basalt-fiber PTM is very robust and corrosion resistant in extreme environments such as a strong acid, organic solvent, and alkali. The water evaporation processes are investigated and the floating-with-insulator mode shows the lowest heat dissipation and highest water evaporation rate. The basalt-fiber fabric is optimized by carbonization and a vaporization rate of 1.50 kg.m(-2).h(-1) and energy utilization efficiency of 82.5% are achieved for evaporation of pure water. The basalt-fiber PTM can be hand washed at least 30 times without efficiency deterioration and the process can be readily scaled up to address commercial needs.

Automated summary

The study introduces an inexpensive and versatile photothermal membrane made from basalt fibers, which exhibit excellent corrosion resistance in extreme environments and high water evaporation efficiency and energy utilization. The membrane can be hand washed multiple times without efficiency deterioration and easily scaled up to meet commercial needs.