Monolithic integrated multifunctional photoelectrochemical device for smart ultraviolet management

Ultraviolet (UV) radiation is crucial for the survival and evolution of organisms, while multifunctional electronics for smart UV management remain undeveloped. Herein, we design a novel monolithic integrated photoelectrochemical (PEC) device, in which the TiO₂ film, meshy Pt layer and viologen solution are used as the photoelectrode, counter electrode, and electrolyte, respectively. The obtained device exhibits three functions, including photodetection, electrochromism, and light-assisted coloration function, which can detect, shield, and trace the UV radiation. Meanwhile, the PEC device possesses excellent properties, including a high photoresponsivity of 20 mA/W, a high coloration efficiency of 236.7 cm²/C at a wavelength of 600 nm, 98.5% UV blocking mainly in UV-A range, and an instant light-assisted coloring process. By combining the passive detecting and the active shielding, the PEC device enables the intelligent management of the UV radiation, which also provides a general strategy for designing and fabricating multifunctional smart electronics.