Photocatalytic Degradation of Gaseous Benzene Using Cu/Fe-Doped TiO2 Nanocatalysts under Visible Light

Abstract

Visible-light-enhanced TiO2 nanocatalysts doped with Cu and Fe were synthesized using the sol–gel method to investigate their performance in degrading gaseous benzene. The structure and morphology of mono- and co-doped TiO2 (i.e., Cu/Fe-TiO2, Cu-Fe-TiO2) were characterized using SEM, EDS, XRD, BET, Raman, UV-vis-DRS, and XPS techniques. The results indicated that the presence of Cu/Fe mono- and co-doped TiO2 leads to the formation of an anatase phase similar to pure TiO2. Furthermore, the introduction of Cu/Fe enhanced the presence of lattice defects and increased the specific surface area of TiO2. This enhancement can be attributed to the increase in oxygen vacancies, especially in the case of Cu-Fe-TiO2. Additionally, Cu-Fe-TiO2 showed a higher concentration of surface-bound hydroxyl groups/chemically adsorbed oxygen and a narrower bandgap than pure TiO2. Consequently, Cu-Fe-TiO2 exhibited the highest photocatalytic performance of 658.33 μgC6H6/(g·h), achieving a benzene degradation rate of 88.87%, surpassing that of pure TiO2 (5.09%), Cu-TiO2 (66.92%), and Fe-TiO2 (59.99%). Reusability tests demonstrated that Cu-Fe-TiO2 maintained a high benzene degradation efficiency of 71.4%, even after five experimental cycles, highlighting its exceptional stability and reusability. In summary, the addition of Cu/Fe to TiO2 enhances its ability to degrade gaseous benzene by prolonging the catalyst’s lifespan and expanding its photoresponse range to include visible light.

Zn-Doped MnCO3/CS Composite Photocatalyst for Visible-Light-Driven Decomposition of Organic Pollutants

“…In the literature, the range of light absorption of the catalyst could be extended by introducing other metal ions [ 15 ]. In addition, it has been reported that doping with elements such as Zn 2+ , Bi 3+ , Fe 3+ , Ni 2+ , and Cu 2+ can increase photocatalytic activity owing to enhanced electron exchange rates and a reduced band gap [ 16 , 17 , 18 ]. For instance, Zn doping enhances the charge separation and the utilization of visible light, and changes band gaps; therefore, porous Zn doped Zr 3+ -ZrO 2 composite showed excellent photocatalytic activity for tetracycline degradation due to its narrow band gaps and broaden visible light [ 16 ].…”

“…It has been reported that Cu- and Fe-doped TiO 2 nanocatalysts reveal more lattice defects and a higher concentration of surface-bound hydroxyl groups/chemically adsorbed oxygen. Consequently, Cu-Fe-TiO 2 composite has demonstrated significant photocatalytic activity, which can be attributed to its reduced band gap [ 18 ].…”

Characterization and Mechanism Elucidation of Nano-TiO2 Composites Prepared by Gaseous Detonation Method

“…Cu 2+ doping improved the wave absorption performance. Tian et al 28 synthesized Cu- and Fe-doped TiO 2 using the sol–gel method, demonstrating that the introduction of Cu and Fe increased the presence of lattice defects and the specific surface area of TiO 2 .…”