Enhancing the efficiency of energy harvesting from salt gradient with ion-selective nanochannel

The development of a nanofluidic energy harvesting system plays a fundamental role in harvesting osmotic power from Gibbs free energy within the salt concentration gradient, which is considered to be a clean and renewable energy source for the future. In this study, a silica-nanochannel based nanofluidic energy harvesting system was fabricated and the output power density reached 705 W m^-2 under suitable KCl concentration bias which exceeded-by almost two orders of magnitude-the results obtained by previous work. The enhancement of energy harvesting was mainly ascribed to the appropriate length of nanochannel that provides a good balance between the desirable ion selectivity and the unfavorable large resistance from the nanochannel. This high-performance nanofluidic energy device could be used in a variety of applications, including to power tiny biomedical devices or for constructing future clean-energy recovery plants.