Novel TiO2/graphene oxide functionalized with a cobalt complex for significant degradation of NOx and CO

Abstract

We are reporting a well-designed nanostructured composite, consisting of titanium dioxide (TiO₂) and cobalt (Co) imidazole (Im) complex functionalized graphene oxide (FGO). The Co–Im complex was attached on the GO by covalent bonding of Im with the graphene functional groups. The films were characterized by XRD, XPS, TEM, UV-vis, FTIR and Raman spectroscopy in order to subsequently prove the evidence of hybridization of GO with the Co–Im complex. The band gap calculated for the TiO₂ thin film was 3.10 eV, 2.96 eV for TiO₂/GO and 2.776 eV for TiO₂/FGO. Experimental results confirmed high-percentage deterioration of NO_x (51%) and CO (46%). The photodegradation experiments revealed a significant photocatalytic character of TiO₂, physical adsorption of GO, and the affinity of cobalt to undergo complex formation with pollutant gases. The TiO₂/FGO composite increases air pollutant degradation by nearly three times that of the bare TiO₂ thin film.