Fabrication and Characterization of Co-Doped Fe₂O₃ Spindles for the Enhanced Photo-Fenton Catalytic Degradation of Tetracycline

Abstract

Co-doped Fe 2 O 3 spindles with different Co contents were successfully fabricated by a facile one-step hydrothermal method. The crystalline structure, morphology, optical properties, and chemical state of the as-prepared catalysts before and after photo-Fenton reaction were characterized. Co 2+ incorporated into the Fe 2 O 3 lattice was confirmed by the above characterizations. Also, the photocatalytic and photo-Fenton catalytic performances of the samples were evaluated by the degradation of tetracycline (TC) under visible light irradiation in the absence/presence of H 2 O 2 . The results demonstrated that Co-doped Fe 2 O 3 spindles exhibited better catalytic degradation performance in comparison with single Fe 2 O 3 spindles, and the sample of Co(5%)-Fe 2 O 3 spindles displayed the highest activity and best stability. The improvement of photo-Fenton activity might be attributed to two reasons: On the one hand, Co-doped Fe 2 O 3 spindles not only formed the Fe vacancies to reduce the band gap but also could build up an internal electric field, which inhibits electron/hole pair recombination and facilitates the transfer of photoexcited charge carriers. On the other hand, the intrinsic Co 2+ /Co 3+ redox cycling can accelerate the circulation between Fe 2+ and Fe 3+ in Co(5%)-Fe 2 O 3 spindles to facilitate H 2 O 2 consumption and produce more ·OH radicals for TC degradation.

Multistep Quenching of a Rust-Derived Catalyst for Enhanced Volatile Organic Compound Catalytic Oxidation

“…As presented in Figure S9, the Raman shifts observed at 213 and 270 cm −1 could be attributed to the A 1g and E g mode characteristic of Fe 2 O 3 . 16,29 When compared with the A 1g Raman mode of Fe 2 O 3 (212.7 cm −1 ) and Sn s :Fe 2 O 3 (212.3 cm −1 ), the red shift and a slightly broader full width at half-maximum (fwhm) on the Raman spectra of Sn q :Fe 2 O 3 (209.6 cm −1 ) indicated the creation of oxygen vacancies, resulting from the Sn doping and quenching step (Table S3). 30 Moreover, compared with the A 1g Raman spectra of Pt q /Fe 2 O 3 (212.7 cm −1 ) and Pt q /Sn s :Fe 2 O 3 (212.3 cm −1 ), that of Pt q / Sn q :Fe 2 O 3 downshifted to 210.2 cm −1 and showed broadened peaks, indicating that more vacancies were generated on Pt q / Sn q :Fe 2 O 3 (Figure S9 and Table S3).…”

Promoted photo-Fenton reactivity through electron transfer between non-contacted Au nanoparticles and Fe2O3 nanowires in a confined space

“…Crystal lattice distances of 0.25 nm and 0.23 nm were assigned to the Fe 2 O 3 (110) and Au (111) planes, respectively. 34,35 The energy-dispersive X-ray spectroscopy (EDS) mapping in Fig. 1e confirmed that the Au nanoparticles were evenly distributed on the inner surface of the SiO 2 shell, while the Fe 2 O 3 nanowires acted as the inner cable, further suggesting that the Au NPs and Fe 2 O 3 nanowires were not in direct contact.…”

Review on cobalt ferrite as photo-Fenton catalysts for degradation of organic wastewater

“…25 The photo-Fenton degradation efficiency of TC by Co-doped Fe 2 O 3 is significantly higher than that of single Fe 2 O 3 . 26 Moreover, Co–Fe co-doped SiO 2 also shows superior catalytic performance, which can achieve 98% degradation of CIP in 10 min. 27 This is because the introduction of other metal ions into the catalyst can accelerate the regeneration of Fe 2+ in the Fenton catalysis process, which has a positive effect on the generation of free radicals and will greatly improve the catalytic efficiency of the catalyst.…”