Novel Magnetic Fe₃O₄/α-FeOOH Nanocomposites and Their Enhanced Mechanism for Tetracycline Hydrochloride Removal in the Visible Photo-Fenton Process

Abstract

Magnetic Fe 3 O 4 /α-FeOOH heterojunction nanocomposites (denoted as Fe-NCs) have been synthesized by a fast one-pot hydrothermal method. The obtained Fe-NCs contain rich micropores with a high surface area of 135.15 m 2 /g. The different phases in the composites can efficiently enhance the visible-light absorption, improving the separation and transfer of photogenerated electron–hole pairs during the photocatalytic reaction. Thus, they show excellent degradation and mineralization of tetracycline (TC) over a wide pH range (5–9) in the visible photo-Fenton reaction. Especially, the catalyst exhibits the highest adsorption capacity toward TC at a neutral pH, which facilitates the surface reactions of TC with active species. Experiments evidence that the high production of photogenerated holes and superoxide radicals (O 2 •– ) in Fe-NCs are favorable to the high catalytic efficiency. Combined with liquid chromatography–mass spectrometry, the possible pathway toward TC degradation was proposed.

CuS@Cu-CD composites as efficient heterogeneous Fenton-like catalysts for the photodegradation of tetracycline

“…Table 1 lists a comparison of removal efficiencies of tetracycline in the present work with some reported Fenton-like catalysts. 43,49–51 As displayed, our designed catalyst exhibits relatively higher catalytic activity than those reported in the literature for the photodegradation of TC in the water.…”

Fe3O4 Nanoparticles Synthesized from Waste Iron Dust for Sunlight-Boosted Photodegradation of Nitrophenols and Their Mixtures

“…Advanced oxidation processes involving the influence of sunlight to improve the photodegradation rate possess enormous potential to be included in improving the present methodologies used for wastewater treatment. − One such example is the Fenton oxidation method, which is well-known and has been extensively investigated in wastewater treatment. , The simpler and well-explored examples involving Fenton-like oxidation reactions are iron-based catalysts such as Fe (oxy) hydroxides, namely, magnetite, , ferrihydrite, and hematite . Of them, magnetite (Fe 3 O 4 ) as a heterogeneous catalyst has always been advantageous as it can be easily magnetically separated from the solution. , Thus, the simple and viable synthesis of inverse spinel of Fe 3 O 4 at low cost and its use for the removal/degradation/photodegradation of complex toxic organic moieties in wastewater are significant areas of research interest .…”

Photoactive Fe3O4@Fe2O3 Synthesized from Industrial Iron Oxide Dust for Fenton-Free Degradation of Multiple Organic Dyes

“…Iron-based materials/nanomaterials showed a wide range of applications, especially their catalytic activities in various organic and inorganic reactions. − Additionally, showed their potential to acquire usable water from the contaminated wastewater using the process of advanced oxidation processes (AOP) including light-induced AOP. − During the AOP, the complex organic frameworks of organic pollutants are broken into small molecular weight hydrocarbons, carbon dioxide, and water, while in the case of inorganic contaminants they are reduced from higher toxic oxidation states to lower nontoxic oxidation states . From the many active iron-based catalysts as their (oxy) hydroxides, such as hematite, magnetite, ferrihydrite, etc., magnetite (Fe 3 O 4 ) and magnetite-based heterogeneous materials have been preferred for the photodegradation applications because of their easier separations after the experiments from the reaction mixture, such as Fe 3 O 4 @void@CdS, Fe 3 O 4 @rGO@TiO 2 , Fe 3 O 4 @Polydopamine-Ag Core–Shell, and Fe 3 O 4 @β-ketoenamine used for the degradation of methylene blue (MB) dye, Fe 3 O 4 /α-FeOOH Nanocomposites for removal of tetracycline hydrochloride, Fe 3 O 4 /CeO 2 for degradation of 4-chlorophenol, and Fe 3 O 4 @EDTA-Ag for degradation of organic dyes including rhodamin B (Rh–B), MB, alizarin yellow (AY), neutral red (NR), orange II/acid orange-7 (Orng-II), and azophloxine (Azp) in aqueous solution …”

“…4−9 During the AOP, the complex organic frameworks of organic pollutants are broken into small molecular weight hydrocarbons, carbon dioxide, and water, 10 while in the case of inorganic contaminants they are reduced from higher toxic oxidation states to lower nontoxic oxidation states. 11 From the many active iron-based catalysts as their (oxy) hydroxides, such as hematite, 4 magnetite, 12 ferrihydrite, 13 etc., magnetite (Fe 3 O 4 ) and magnetite-based heterogeneous materials have been preferred for the photodegradation applications because of their easier separations after the experiments from the reaction mixture, 14 such as Fe 3 O 4 @void@CdS, 15 Fe 3 O 4 @rGO@TiO 2 , 16 Fe 3 O 4 @Polydopamine-Ag Core−Shell, 17 and Fe 3 O 4 @β-ketoenamine 18 used for the degradation of methylene blue (MB) dye, Fe 3 O 4 /α-FeOOH Nanocomposites for removal of tetracycline hydrochloride, 19 Fe 3 O 4 /CeO 2 for degradation of 4-chlorophenol, 20 and Fe 3 O 4 @EDTA-Ag for degradation of organic dyes including rhodamin B (Rh−B), MB, alizarin yellow (AY), neutral red (NR), orange II/acid orange-7 (Orng-II), and azophloxine (Azp) in aqueous solution. 21 Concerning water contaminants, industrial effluents are released from carpet, paper, textile, distillery, leather, and printing in large amounts and contains a lot of toxic organic dyes.…”