Low-cost 2D nanochannels as biomimetic salinity- and heat-gradient power generators

Abstract

Organisms can make use of the ion channels embedded on the cell membranes to harvest osmotic energy and heat energy, which provides inspirations to design artificial nanochannel-based power generators. Herein, two-dimensional (2D) montmorillonite (MMT) nanochannels are fabricated with a facile method of direct assembling the exfoliated monolayers in a liquid phase to achieve the biomimetic power generation from salinity- and heat-gradient. The high cation selectivity and sufficient ion flux enable MMT nanochannels to present high power densities of ∼4.58 W/m2 under 50-fold concentration gradient and ∼0.47 W/m2 under 30 °C temperature gradient, respectively. The performance can be further improved to ∼8.53 W/m2 to harvest the energy stored in the thermal-osmotic gradient. The facile and cost-effective MMT nanochannels open new insights into biomimetic energy conversion from various sources.