Sunlight-assisted enhancement of hydroelectric generators utilizing p-type and n-type CNT fabrics

Abstract

Hydrovoltaic technology harnesses the ubiquitous and perpetual hydrologic cycle for solid–liquid interfacial energy conversion. However, contemporary hydrovoltaic systems exhibit multifaceted performance degradation, which includes dopant dissolution, destabilization of the electric double layer, and interfacial recombination. These factors collectively impair operational consistency and commercial viability. To address these limitations, we have developed sunlight-regenerable generators based on p-/n-type carbon nanotube (CNT) organic fabrics fabricated via scalable drop-casting techniques. The doped p-/n-type CNT organic fabrics facilitate photo-triggered recovery effects under AM 1.5 G irradiation (100 mW/cm2). Spectral and thermal analyses confirm that the recovery mechanism is primarily photo-triggered and is cooperatively assisted by photothermal effects, thereby restoring interfacial functionality. The system achieves markedly improved sustained voltage/current output, a higher peak power density of 16.46 μW at a 10 kΩ load resistance, and scalable integration with an output of 8.7 V from 20 serially connected units and 15.5 mA from 40 parallelly connected units. This work establishes a solar-hydro synergistic strategy for resolving the stability-compatibility dilemma in hydrovoltaic energy harvesting.