A Mild in-Situ Method to Construct Fe-Doped Cauliflower-Like Rutile TiO2 Photocatalysts for Degradation of Organic Dye in Wastewater

Abstract

A mild in situ method was developed to construct an iron doped rutile TiO2 photocatalyst like cauliflower for degradation synthetic textile dye-methyl orange. The synthesized photocatalysts presented distinguished photocatalytic activity. At the optimal Fe concentration (0.5%), the decomposition rate of methyl orange (MO) was about 90% under 40 min of ultraviolet (UV) light irradiation. Whereas, to our knowledge, only 70% of the decomposition rate of MO was achieved by commercial photocatalyst P25 under the similar reaction condition. Additionally, the rutile preparation temperature did not exceed 100 °C, which was much lower than the traditional preparation calcination temperature (e.g., 600 °C). The specific surface area of Fe doped catalysts was bigger than that of the control sample and the catalyst characterization indicated that the doped iron was incorporated into the rutile TiO2 lattice and resulted in the lattice disorder. The lattice disorder would have generated surface defects in the crystal structure, which was in favor of the photocatalytic reaction. The UV-Vis diffuse refection characterization and Density Functional Theory (DFT) calculation suggested that doping a small amount of Fe into the lattice of rutile would lead to a narrower band gap and the formation of a doping energy level between conduction and valence bands of TiO2. This further increased the degradation efficiency of synthetic textile dyes in wastewaters. Our study has provided a relatively easy operation for synthesis Fe doped rutile TiO2, which is a benefit to decrease the cost in wastewater treatment process.

Degradation of Sulfamethoxazole Using Iron-Doped Titania and Simulated Solar Radiation

“…In recent studies, iron-doped titania nanoparticles and thin films were synthesized, characterized and tested for the degradation of methylene blue [30], phenol [31] and nitrobenzene [32] in water under visible irradiation. In other studies [33], a low-cost and easy procedure was established to synthesize an iron-doped titania, a cauliflower-like photocatalyst for the degradation of azodyes in water.…”

Density functional theory for doped TiO2: current research strategies and advancements

“…The calculation results obtained by Khan and Zeng demonstrated similar band gap values of 2.13 eV for pure anatase TiO 2 [96]. In the studies devoted to DFT calculations of the pure rutile TiO 2 electronic structure, the application of GGA functional also produced underestimated band gaps compared to experimental value (3 eV): 1.917 eV [12] and 2.92 eV [107], for example.…”

Photocatalytic and Electrocatalytic Properties of Cu-Loaded ZIF-67-Derivatized Bean Sprout-Like Co-TiO2/Ti Nanostructures

“…For the Raman spectrum of a Co-TiO 2 /Ti sample, very broad and strong Raman peaks were observed at 270 cm −1 , 439 cm −1 and 610 cm −1 , in addition to weaker and sharper Raman peaks at 141 cm −1 , 192 cm −1 , 482 cm −1 , 522 cm −1 , 620 cm −1 and 689 cm −1 . Three characteristic Raman active peaks at 141 cm −1 , 439 cm −1 and 610 cm −1 could be assigned to the B 1g , E g and A 1g modes of rutile TiO 2 , respectively [ 40 , 41 ]. The corresponding peak at 240 cm −1 is due to the multi-phonon scattering process [ 41 ].…”