Photoelectrochemical switch based on cis-Azobenzene chromophore modified TiO2 nanowires

Carboxylated-azobenzene chromophore modified TiO2 nanowire composites were prepared and characterized. Photocurrent measured with monochromatic incident light irradiation results showed that azobenzene modified TiO2 nanowire electrode had obviously higher photocurrent and broader visible light response covering range of 350–650 nm, and the wavelength position corresponding to the maximum photocurrent was red shift to about 470 nm. After alternate irradiation with UV and visible light, the azobenzene modified TiO2 nanowire electrode exhibited obvious photoelectrochemical switching properties. Furthermore, the photocurrent under visible light irradiation was much higher than that under UV irradiation due to the cis-to-trans isomerization transformation of azobenzene chromophore.