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

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.