Pyridyl anchor-assisted photoresponsiveness of 4-(4-diethylaminophenylazo)pyridine on TiO2 surface

Abstract

The adsorption of organic molecule on metal oxide surfaces via a suitable anchoring group is important to realize various optoelectronic devices and surface switches. In this manuscript, we investigate the pyridyl anchor-assisted molecular adsorption of an azo dye 4-(4-diethylaminophenylazo)pyridine on TiO2 surface and the photoresponsiveness of the pyridyl anchoring-containing dye/TiO2 interfacial structure. The photoisomerization and photocurrent generation of the azo dye are activated on the TiO2 surface via the pyridyl anchor, which are otherwise unavailable when the azo dye is in the free form in the solution. The first-principles calculations elucidate the detailed nanoscopic structure and optoelectronic properties of the different molecule/TiO2 isomers. This manuscript highlights the potentials of the pyridyl anchor to substitute the traditional carboxylate group for the surface photoisomerization and photoresponsive studies, which can benefit various TiO2-incorporated surface switches and optoelectronic devices.