Efficient solar energy conversion via bionic sunlight-driven ion transport boosted by synergistic photo-electric/thermal effects

Abstract

Mimicking smart light-controlled ion transport in biological channels exhibits exceptional application potential. However, to achieve efficiency comparable to those of biological counterparts, both constructing delicate nanoarchitectures and developing novel light-responsive mechanisms are urgently required. Herein, unique light-regulated ion transport driven by a photo-electric/thermal synergistic effect was realized in a two-dimensional Ti₃C₂T_x/g-C₃N₄ heterogenous nanochannel. Under illumination, the separation of photoexcited charge carriers in nanofluidic channels directly prompted spontaneous ion migration. Furthermore, benefiting from the light-to-heat conversion of Ti₃C₂T_x channels, the temperature field further reinforced the transport motivation. On this basis, effective modulation of ionic diffusion was achieved even under natural sunlight. In this regime, not only osmotic power in traditional salinity-gradient systems could be efficiently harvested with the help of light irradiation, but also the ionic energy could be successfully converted into electricity in a symmetric solution system. Our work opens up an avenue for the design of intelligent light-triggered nanochannels for solar energy conversion and storage.