Pt@WS2 Mott–Schottky Heterojunction Boosts Light-Driven Active Ion Transport for Enhanced Ionic Power Harvesting

Abstract

Bioinspired light-driven ion transport in two-dimensional (2D) nanofluidics offers exciting prospects for solar energy harvesting. Current single-component nanofluidic membranes often suffer from low light-induced driving forces due to the easy recombination of photogenerated electron–hole pairs. Herein, we present a Pt@WS₂ Mott–Schottky heterojunction-based 2D nanofluidic membrane for boosting light-driven active ion transport and solar enhanced ionic power harvesting. The photovoltaic effect in the Mott–Schottky heterojunctions and photoconductance effect in WS₂ multilayers account for more efficient charge separation across the nanofluidic membrane. In an equilibrium electrolyte solution, we observe directional cationic transport from the WS₂ to the Pt region under visible-light illumination. In 10^–3 M KCl electrolyte, the photocurrent and photovoltage reach 11.84 μA cm^–2 and 30.67 mV, respectively. Moreover, the output power can reach up to 5.02 W m^–2 under light illumination, compared to a value of 2.56 W m^–2 without irradiation. This work not only introduces a driving mechanism for boosting ion transport but also offers a pathway for integrating multiple energy sources.