Robust Membrane for Osmotic Energy Harvesting from Organic Solutions

Using particulate nanochannels for desired ions transport is a potential technology for nanofluidic osmotic energy harvesting. However, the finite fresh water as an essential part of this harvesting system limits its development. Therefore, developing a robust membrane for harvesting energy from other solutions such as waste organic solutions is attractive. Here, we develop bioinspired membrane based on boron nitride flakes and aramid nanofibers with nanochannels via a layer-by-layer assembly technique for harvesting nanofluidic energy from organic solutions directly. Enhancement of the synergistic effect of the boron nitride flakes and aramid nanofibers endows the aramid-boron nitride (ABN) membrane with a superstrong mechanical performance (360 MPa). The ABN membrane showed a pressured-induced current in LiCl-methanol solution and NaCl-ethanol solution, respectively. More importantly, the ABN membrane exhibited outstanding stable and high-energy harvesting with salinity gradient dependence in LiCl-methanol, LiCl-ethanol, and NaCl-ethanol solutions, respectively. Impressively, the voltage produced from the organic solutions (LiCl-methanol, Ch/Cl = 1000) can power the transistor and it works well for 1 h as a gate voltage. The design of bioinspired membrane enables a robust and efficient harvesting of osmotic energy from organic solutions.