Improvement of photocatalytic activity of TiO2 via a dual approach, consisting of iron doping and incorporation in Cu-based metal-organic framework

Abstract

In attempt to develop an efficient photocatalyst, TiO₂ particles were doped with iron to give Fe–TiO₂ particles with lower band-gap energy (2.25 eV). The resultant particles were then incorporated in Cu-based metal-organic framework with high specific surface area (1151 m²g^-1) via in-situ approach to furnish a photocatalytic nanocomposite, which was comprehensively characterized via FTIR, XRD, BET, XPS, SEM/EDS, TEM and DRS. The results underlined that metal-organic framework was successfully formed in the presence of Fe–TiO₂ particles and the particles were located on the surface and within the pores of metal-organic framework. Moreover, the band-gap energy of the composite was measured as 2.60 eV. The photocatalytic activity of the as-prepared photocatalyst was assessed for degradation of Congo red dye under UV light irradiation and the effects of influential parameters, such as dye initial concentration and catalyst loading were investigated. The results confirmed high photocatalytic activity of the composite (89 % degradation yield), which was superior compared to that of its components, confirming the synergistic effects. Furthermore, the composite was recyclable and could be recovered and reused for six successive runs with slight loss of activity and leaching of Fe–TiO₂ (1 wt%). Kinetic studies also indicated that photodegradation proceeded via a second-order model.