Photoinduced Cation Coupled Electron Transfer for Efficient Ionic Power Harvesting Based on CNT/MoS₂ Heterostructures

Inspired from the light-driven proton-coupled electron transfer during photosynthesis in green plants, an engineered CNT/MoS₂ biomimetic nanofluidic system has been successfully developed, which achieves photo-activated ion transport in iso-concentration electrolytes through synergistic photothermal-photoelectric coupling. Under light irradiation, localized photothermal effects in CNT generate a temperature gradient, driving thermophoretic ion migration, while the same irradiation triggers a MoS₂-mediated surface charge gradient via photoexcited carrier redistribution, encompassing both vertical charge transfer and horizontal carrier diffusion. The resultant dual gradients of surface charge asymmetry and temperature differential cooperatively drive autonomous ion pumping. Experimental and theoretical analyses reveal that the temperature gradient dominates the initial unidirectional migration of ions, whereas the surface charge gradient further enhances active ion transport. The synergistic interplay of these gradients yields a unidirectional ion flux, enabling efficient ionic energy harvesting with an output power density of 18.98 mW m^-2 and an energy conversion efficiency of 8.3 × 10^-4%. Systematic investigations of illumination conditions (214-759 mW cm^-2), electrolyte concentration (10^-6-10^-1 m), pH (2-10), and ion species (K⁺ → Mg²⁺) confirm robust adaptability across diverse conditions, establishing a blueprint for artificial non-equilibrium iontronics that merges biological transport principles with opto-nanofluidic engineering for sustainable energy harvesting.