“Quasi-In Situ Synthesis of Oxygen Vacancy-Enriched Strontium Iron Oxide Supported on Boron-Doped Reduced Graphene Oxide to Elevate the Photocatalytic Destruction of Tetracycline”

Abstract

The efficient use of visible light is necessary to take advantage of photocatalytic processes in both indoor and outdoor circumstances. Precisely manipulating the in situ growth method of heterojunctions is an effective way to promote photogenerated charge separation. Herein, the SrFeO 3 @B-rGO catalyst was prepared by an in situ growth method. At a loading of 10 wt % B-rGO, the nanocomposites revealed an excellent morphology and thermal, optical, electrochemical, and mechanical properties. X-ray diffraction analysis revealed the cubic spinel structure and a space group of Pm ̅ 3m for SrFeO 3 . High-resolution scanning electron microscopy and high-resolution transmission electron microscopy show the core−shell formation between SrFeO 3 and B-rGO. Furthermore, density functional theory of SrFeO 3 was performed to find its band structure and density of states. The SrFeO 3 @B-rGO nanocomposite shows the degradation rate of tetracycline (TC) reaching 92% in 75 min and the highest rate constant of 0.0211 min −1 . To improve the catalytic removal rate of antibiotics, the efficiency of e − and h + separation must be improved, as well as the generation of additional radicals. Radical trapping tests and the electron paramagnetic resonance method indicated that the combination of Fe 2+ and Fe 3+ in SrFeO 3 effectively separated e − and h + while also promoting the development of the superoxide anion ( • O 2 − ) to accelerate TC degradation. The entire TC degradation pathway using high-performance liquid chromatography and its mechanism were discussed. As a whole, this study delineates that photocatalysis is a viable strategy for the treatment of environmental antibiotic wastewater.

Synthesis of Acid Mine Drainage (AMD) Sludge-Derived Al–Fe3O4 as Fenton-like Catalysts for the Efficient Degradation of Tetracycline

“…However, the removal efficiency of TC solution did not change significantly when the H 2 O 2 concentration was up to 0.67 mL/L, which showed that excess H 2 O 2 could be turned into a scavenger of ·OH (eqs –) . In addition, the total organic carbon (TOC) measurement showed that the TC mineralization rate was 53.5% in the Al–Fe 3 O 4 + H 2 O 2 system, which confirmed that most of the TC molecules were mineralized to CO 2 and H 2 O by elimination and ring-opening reactions at the end, and the remainder exists in the form of intermediates, which possess relatively lower acute toxicity and chronic toxicity compared to those of TC. − 4 · O H → 2 H 2 O + O 2 O H + · O H → H 2 O 2 ·O H + H 2 O 2 → H 2 O + H O· 2 …”

Shining a light on fungicide- water: enhanced photocatalytic degradation using the CoTiO3/CaTiO3 nanocomposite and experimental and theoretical viewpoints on improved intervalence charge transfer from O2− to Ti4+ and from Co2+ to Ti4+ ions and spatial charge transfer

“…The XPS spectra of the samples were probed for the investigation of surface chemical composition and chemical valence state through measurement of the elemental binding energies (BE). 46 Fig. 2 shows all the core-level and sub-core-level peaks of constituent elements present in the XPS survey scan for the bare CoTiO 3 , CaTiO 3 , and CCO 75 : 25 composite.…”