A bio-inspired transpiration ion pump based on MXene

Abstract

Transpiration as one of the plant's vital movements can also be seen as a pump that pumps nutrients such as water and inorganic salts from the roots to the leaves. Learning of this process might find many applications in nanotechnology, materials science or bioscience. Here, we were inspired by the transpiration of plants and the remarkable photothermal conversion characteristic of MXene Ti₃C₂T_x, constructing a biomimetic transpiration ion pump based on macroscale evaporation induces nanofluidic ionic transportation. This device can pump ions with an inverse concentration gradient of 200-fold under asymmetric infrared light. Besides, such a device with reversible regulation and fast light response can also act as an energy conversion set-up, which generates a stable current and voltage of about 7.3 μA and 13.6 mV, respectively, at an infrared light intensity of ∼600 mW cm⁻². This conception of a biomimetic ion pump with a simple construction process might provide an idea for the potential research of power harvesting and energy conversion.