Heat and osmosis cooperatively driven power generation in robust two-dimensional hybrid nanofluidic channels

Abstract

The conversion of osmotic energy and low-grade heat into electricity provides new solutions to the looming energy crisis. The cooperative utilization of these two kinds of renewable energy sources might enhance the power generation density. Herein, we demonstrate heat and osmosis cooperatively driven power generation in 2D hybrid nanofluidic channels composed of montmorillonite and graphene oxide nanosheets. The hybrid nanochannels exhibit enhanced mechanical strength, cation selectivity and ion flux when compared with single-component nanochannels. With the cooperation of osmosis (artificial sea/river water) and heat (50 °C gradient), the hybrid nanochannels output a high power density of ∼10.29 W m⁻², which is improved by 96% when compared with the power density under a single osmotic gradient. The cooperation effect can be ascribed to the enhanced ion permeation from high to low concentrations by judiciously engineering the direction of the heat gradient, which is subsequently supported by theoretical simulations. Our work demonstrates the potentiality to maximize power generation by cooperatively harvesting multiple renewable energies.