Ultraviolet-Light-Driven Electricity Generation by a TiO₂/Graphene Composite in Water

Photoinduced power generation from solid/liquid heterojunctions is an environmentally friendly method to alleviate the energy crisis. However, the utilization of volatile and corrosive electrolytes weakens the stability of harvesting solar energy, and it is challenging to obtain flexibility because of the device architecture. This study reports the fabrication of a novel photo-to-electrical energy conversion device based on a TiO 2 /graphene/thermoplastic polyurethane (TPU) composite film in water. Under ultraviolet (UV) light illumination, an output voltage of 0.52 V and power density of 2.32 mW/m 2 were generated. A stable output voltage of 1.53 V was achieved by connecting three generators in series. Moreover, the generator shows efficient and stable energy harvesting from sunlight outdoors. Based on the output behavior of the device, a working mechanism based on ultraviolet-light-induced radical recycling at the electrodes was proposed. This new photo-to-electrical energy conversion technology may provide a general approach to meet the energy requirements of electronic devices and a novel method for fabricating self-powered UV sensors.