Nano-silver incorporated amine functionalized graphene oxide titania nanotube composite: a promising DSSC photoanode

Abstract

BackgroundIn dye-sensitized solar cell (DSSC), the semiconductor photoanode plays a vital role in gathering photo-excited electrons from the sensitizer. Generally, the photoconversion efficiency of photoanode is hampered by electron-hole recombination. To circumvent this, modification of TiO2 nanotubes with amine functionalized graphene oxide (GO) has been attempted. MethodsNanocomposites consisting of ethylenediamine functionalized graphene oxide (GO/NH2) and titania nanotubes (TiO2 NTs) are prepared by hydrothermal method and are incorporated with 3 wt% of Ag nanoparticles. The nanocomposites are studied using diffuse reflectance spectroscopy, Raman spectroscopy, XRD, TEM and XPS techniques. Significant FindingsThe GO surface acquire defect structure and disorder after amine functionalization which occurs via reactive oxygen groups to form C−N bond. The nano-silver incorporated amine functionalized GO modified TiO2 nanotubes (TiO2 NTs-GO/NH2/Ag) exhibit high dye adsorption capacity and leads to more light gathering. The DSSC fabricated with TiO2 NTs-GO/NH2/Ag photoanode exhibits very good photo-conversion efficiency (8.18%). Significant light-to-electrical energy conversion efficiency of the TiO2 NTs-GO/NH2/Ag photoanode DSSC is due to the efficient charge transport at the interfaces, high dye loading and broad absorption by the sensitizer adsorbed TiO2 NTs-GO/NH2/Ag thin-film.