photo-Fenton Catalyst Research Articles

Design of micro-nano spherical β-NiOOH/FeMoO4 composite with enhanced photo-Fenton performance

In this work, micro-spherical β-NiOOH/FeMoO4 with multiple active sites was prepared by one-step solvothermal method and its performance in the photo-Fenton system was investigated. The results indicate that highest degradation efficiency of methylene blue (MB) was obtained when the molar ratio of nickel to iron was 1:2.5. In addition, composites were assessed for its degradation performance for MB by adjusting the concentration of H2O2, pH and catalyst dosage. The pseudo-first-order kinetic rate constant of MB degradation in β-NiOOH/FeMoO4 catalyzed photo-Fenton system was 0.234 min−1 about 5 folds that of pristine FeMoO4 micro-sphere. The degradation mechanism of MB was deduced by active species quenching experiments and technology of coumarin fluorescent probe. And its degradation pathway was proposed by LC-MS identifying reaction intermediates produced during photo-Fenton catalysis. Recycling tests have confirmed excellent stability of β-NiOOH/FeMoO4 composite. In conclusion, this study demonstrates the β-NiOOH/FeMoO4 composite is a promising heterogeneous photo-Fenton catalyst.

Amino-functionalized MIL-88B as heterogeneous photo-Fenton catalysts for enhancing tris-(2-chloroisopropyl) phosphate (TCPP) degradation: Dual excitation pathways accelerate the conversion of [tbnd]FeIII to [tbnd]FeII under visible light irradiation

In this work, the amino-functionalized metal-organic frameworks (MIL-88B-NH2) was synthesized, characterized and used as heterogeneous photo-Fenton catalyst for tris-(2-chloroisopropyl) phosphate (TCPP) degradation. The photo-Fenton activity of MIL-88B-NH2 was investigated on the basis of influence factors, such as initial pH and TCPP concentration, and coexisting impurities. The results revealed that MIL-88B-NH2+H2O2+Vis system exhibited a satisfactory degradation efficiency of TCPP (almost 100%) within 60 min accompanied by a good reusability. Noticeably, the degradation kinetics constant of TCPP by MIL-88B-NH2+H2O2+Vis system was 0.086 min−1, which was visibly higher than that of MIL-88B+H2O2+Vis system (0.021 min−1) since the addition of amino-functionalized organic linker inhibiting the recombination rate of the photo-generated electron-hole pairs and improving the visible light response. Combined with the characterization, the conversion of FeIII to FeII could be accelerated by the photo-generated electron from the excitation of Fe-O clusters and NH2 functionalities, which strengthened the decomposition of H2O2 and formed plenty •OH. Simultaneously, six steady products were validated and potential degradation pathways of TCPP were proposed. It was anticipated that MIL-88B-NH2 could be considered as a desirable and alternative candidate in the application of heterogeneous photo-Fenton reaction to control the environmental risks caused by organophosphate flame retardants (OPFRs).

Applicability of amethyst mining rejects as a novel photo-fenton catalyst for the abatement of an emerging pollutant in water

For the first time, the applicability of amethyst mining rejects as a novel photo-Fenton catalyst was evaluated. Catalyst characterization was analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), specific surface area (BET), and X-ray fluorescence (FRX). The effects of operating parameters, such as pH (2.0–4.0), catalyst dosage (0.25–1.0 g L−1), and H2O2 concentration (2.5–8.5 mmol L−1) on the degradation efficiency of Ponceau 4R dye were evaluated. The amethyst mining rejects presented a mesoporous structure, an average pore size of 9.73 nm, a specific surface area of 13.43 m2 g−1, and 23%wt of Fe2O3 on its chemical composition. The material showed an excellent catalytic efficiency, reaching 97.02% decolorization at 60 min and 75.40% TOC removal at 300 min, in the following reaction conditions: catalyst dosage: 0.75 g L−1, H2O2 concentration: 4.5 mmol L−1, and pH: 3. The waste also showed high stability and effectiveness after three successive reuse cycles. In addition, the catalyst was highly effective for treating synthetic wastewater composed of various hazardous dyes and salts.

Mesoporous structure and amorphous Fe-N sites regulation in Fe-g-C3N4 for boosted visible-light-driven photo-Fenton reaction

Heterogeneous photo-Fenton catalysts prepared by doping metal ions in g-C3N4 are promising alternatives to traditional homogeneous Fenton catalysts, but are restricted by poor mesoporous structure and agglomerate of metal species. Recently, the highly uniformly dispersed metal-N active sites in various photocatalysts have been proved to be the critical reason for their enhanced catalytic activity. In this study based on reasonable control of mesoporous structure and metal-N active sites, mesoporous Fe-g-C3N4 was synthesized using a simple one-step thermal shrinkage polymerization method using ferrous oxalate as iron source and pore-forming agent. The Fe and N elements in the triazine ring skeleton of Fe-g-C3N4 form a σ-π bond, thus the photogenerated electrons can be quickly transferred to Fe3+ to form Fe2+ under the interaction of chemical bonds, accelerating the Fenton reaction rate. Density functional theory calculations results demonstrate that the energy band structure and electron cloud density distribution of Fe-Nx active structure are better than that of routine FeOx crystal structure with metal species agglomeration. In addition, the excellent mesoporous structure of Fe-g-C3N4 creates conditions for the high exposure of Fe-Nx active sites in the photo-Fenton reaction under visible light. The as-developed Fe-g-C3N4 system shows high recyclability and excellent photo-Fenton performance for removal of typical intractable pollutants (The degradation rate of dye and tetracycline reaches 98.2% and 98.7% at 60 and 120 min, respectively). This work provides a facile and sustainable route to develop mesoporous highly-active heterogeneous Fenton-like catalysts and even further general the design of general catalyst with ideal metal-N active sites, thereby promoting a feasible and efficient wastewater remediation solution.

Facile Synthesis of Carbon- and Nitrogen-Doped Iron Borate as a Highly Efficient Single-Component Heterogeneous Photo-Fenton Catalyst under Simulated Solar Irradiation.

The development of a heterogeneous catalyst for use in environmental remediation remains a challenging and attractive research endeavor. Specifically, for Fenton reactions, most research approaches have focused on the preparation of iron-containing heterostructures as photo-Fenton catalysts that utilize visible light for enhancing the degradation efficiency. Herein, the synthesis and novel application of C,N-doped iron borates are demonstrated as single-component heterogeneous photo-Fenton catalysts with high Fenton activity under visible light. Under the optimal conditions, 10 mg of the catalyst is shown to achieve effective degradation of 10 ppm methylene blue (MB) dye, Rhodamine B (RhB) dye, and tetracycline (TC) under simulated solar irradiation with a first-order rate constant of k = 0.218 min−1, 0.177 min−1, and 0.116 min−1, respectively. Using MB as a model system, the C,N-doped iron borate exhibits 10- and 26-fold increases in catalytic activity relative to that of the 50 nm hematite nanoparticles and that of the non-doped iron borate, respectively, in the presence of H2O2 under the simulated solar irradiation. Furthermore, the optimum reaction conditions used only 320 equivalents of H2O2 with respect to the concentration of dye, rather than the several thousand equivalents of H2O2 used in conventional heterogeneous Fenton catalysts. In addition, the as-prepared C,N-doped iron borate achieves 75% MB degradation after 20 min in the dark, thus enabling the continuous degradation of pollutants at night and in areas with poor light exposure. The stability and recyclability of C,N-doped iron borate for the oxidation of MB was demonstrated over three cycles with insignificant loss in photo-Fenton activity. The high Fenton activity of the C,N-doped iron borate is considered to be due to the synergistic action between the negatively-charged borate ligands and the metal center in promoting the Fenton reaction. Moreover, carbon and nitrogen doping are shown to be critical in modifying the electronic structure and increasing the conductivity of the catalyst. In view of its synthetic simplicity, high efficiency, low cost of reagents, and minimal cost of operation (driven by natural sunlight), the as-prepared heterogeneous single-component metal borate catalyst has potential application in the industrial treatment of wastewater.

High surface area magnetic double perovskite La2AlFeO6 as an efficient and stable photo-Fenton catalyst under a wide pH range

Photo-Fenton process is an efficient way to treat the organic pollutants in wastewater. However, the efficiency is limited by serious leaching of iron ions, separation of spent catalyst from reaction system for facile recycling, acidic reaction environment (pH＜4). Herein, a novel double perovskite photocatalyst La2AlFeO6 with high surface area was developed to counter these issues. By altering complexing agents, iron ion content discrepancy and B’-O-B” varies in La2AlFeO6 led to a high surface Fe3+ ratio and an excellent magnetic property. >98.4% of phenol could be degraded in a wide pH range over La2AlFeO6 because of the high surface Fe3+ ratio and promotion of generated ·OH, ·O2– and 1O2. The excellent magnetic property would contribute to separate catalyst from water, and led the used La2AlFeO6 to be reused after simple deionized water rinsing and air drying without any further treatment or calcination.

Cu(II) doped FeOCl as an efficient photo-Fenton catalyst for phenol degradation at mild pH

In this work, the Cu(II) doped iron oxychloride composites (Cu-FeOCl) were successfully synthesized and applied to the photo-Fenton degradation of phenol for the first time. Effect of various objective parameters on catalytic performance have been systematically evaluated, such as the doping amount of Cu(II), catalyst dose, pH value and H2O2 dose. The Cu(II) doping in FeOCl accelerated significantly the decomposition of H2O2 to generate hydroxyl radicals (•OH). Furthermore, the introduction of Cu(II) would produce lattice defects on the surface of FeOCl, which was benefit for the separation efficiency of the photogenerated electron-hole pairs. The 0.5Cu-FeOCl composite exhibited excellent degradation performance over a wide pH range of 3–8. The 0.5Cu-FeOCl/H2O2/Vis system degraded 95.2% of phenol (20 mg/L) within 14 min and removed 79.9% TOC within 120 min with low dosage of H2O2 (3 mM). The main intermediates of phenol degradation were identified by LC-MS, and a possible photo-Fenton catalytic mechanism for phenol degradation by 0.5Cu-FeOCl catalyst was proposed. This study would provide some new insights into developing photo-Fenton catalysts and treatment of phenolic organic wastewater.

MIL-88/Go derived Fe2O3/rGO as a photo-Fenton catalyst: Free radical generation by multipath electron transfer

Accelerating electron transfer can improve the catalytic performance. MIL-88/Go composites were synthesized by hydrothermal method using the oxygen-containing functional group of graphene oxide (GO) as the MIL-88 unit cell nucleus. Fe2O3/rGO composites with small particle size were prepared by roasting of MIL-88/GO. It has high degradation efficiency (99%) and good recycling performance for tetracycline hydrochloride (TC-HCl) in photo-Fenton system. The combination of oxygen vacancies produced by roasting MIL-88 and the conductivity of reduced graphene oxide (rGO) improves the rate of electron transfer. The efficient electron transfer promotes the formation of OH and O2− and thus improve the catalytic activity.

Synthesis of Template-Free Iron Oxyhydroxide Nanorods for Sunlight-Driven Photo-Fenton Catalysis.

Designing a photocatalyst with high efficiency using semiconductor materials emerges as a promising approach for the treatment of wastewater. At the same time, it is very essential to develop nondestructive, green, and sustainable techniques for the degradation of refractory pollutants. Here, we have demonstrated a facile route to prepare iron oxyhydroxide nanorods (β-FeOOH) without employment of any templating agent via a light-driven solution chemistry pathway and explored the as-prepared nanorods as the photo-Fenton catalyst under solar light irradiation. The photocatalytic experiments were performed toward the degradation of the aqueous solution of two different pollutants, namely, methylene blue and rhodamine B dyes. We have illustrated the effect of pH of the solution together with the concentration of H2O2 during the degradation process and optimized the solution pH as well as the H2O2 concentration. The superb photocatalytic efficiency of β-FeOOH is attributed to the generation of reactive oxygen species in the presence of solar light, and these photo-produced reactive oxygen species assist the degradation process. The excellent photocatalytic efficacy and sustainability of β-FeOOH nanorods along with their effortless synthesis approach point to a cost-effective and environmentally benign pathway in fabricating a highly active photocatalyst for the degradation of organic dyes.

Fe3+-Bridged Cellulose–Alginate Composite Gel Beads as Stable and Effective Photo-Fenton Catalysts

Fe³⁺-Bridged Cellulose–Alginate Composite Gel Beads as Stable and Effective Photo-Fenton Catalysts

Enhanced visible light photo-Fenton-like degradation of tetracyclines by expanded perlite supported FeMo3Ox/g-C3N4 floating Z-scheme catalyst

In the conventional Fenton system, the relatively low efficiency of Fe (II) regeneration is a significant drawback. To address this shortcoming, a novel floating Z-scheme photo-Fenton catalyst FeMo3Ox/g-C3N4/EP was prepared by a facile dip-calcination method, in which iron and molybdenum oxides with mixed valence states (FeMo3Ox) and graphitic carbon nitride (g-C3N4) were loaded on the expanded perlite. The removal efficiencies reached the maximum at 98.0%, 93.1% and 97.1% for tetracycline, oxytetracycline and chlortetracycline, respectively, after 60 min dark adsorption and 60 min photo-Fenton process. The aid of dual ion (Fe and Mo) synergy system and photoreduction by Z-scheme photocatalyst enhanced the Fe (II) regeneration, resulting in the excellent performance. Radical scavenger experiment, electron spin resonance spectra (ESR) and X-ray photoelectron spectra (XPS) were used to confirm the mechanism of free radicals’ formation and Fe/Mo redox cycling. ·OH, ·O2- and 1O2 played important roles in the pollutant’s degradation, while the generation of ·O2- was enhanced due to the floatability in this system. The possible degradation pathways of TC were put forward according to the results of mass spectrum and Orbital-Weighted Fukui Function. Overall, this work provides new insights on the cooperation between iron-based mix oxides and semiconductor in the photo-Fenton system.

Engineering FeS2 nanoparticles on tubular g-C3N4 for photo-Fenton treatment of paint wastewater

An efficient photo-Fenton catalyst (FeS2@HTCN) was designed by maximizing the synergistic effect of FeS2 nanoparticles and hollow tubular g-C3N4 (HTCN). Molecule self-assembly and molten salts-assisted calcination were used to engineering the hollow structured g-C3N4 before anchoring FeS2 nanoparticles on the walls of HTCN via reflux method. Compared to bulk g-C3N4, the unique structure of HTCN and heterojunction in the composite endowed FeS2@HTCN with more active sites and abundant channels for electron transfer and charge separation. The enriched electrons can improve the Fe3+ recycling and boost Fe2+ catalyzed •OH production via H2O2. As-prepared photo-Fenton catalyst was successfully applied to the treatment of industrial paint wastewater. The paint wastewater with its COD as high as 8200 mg/L can be effectively degraded with 0.2 mol/L H2O2 in 90 min under visible light irradiation. The photo-Fenton system was further evaluated according to the process stability and economic benefit, proving that the strategy presented in this work would be applicable to the treatment of real wastewater.

An efficient photocatalytic degradation of nitrophenols using TiO2 as a heterogeneous photo-Fenton catalyst

An efficient photocatalytic degradation of nitrophenols using TiO2 as a heterogeneous photo-Fenton catalyst

Efficient Fenton-Like Catalysis Boosting the Antifouling Performance of the Heterostructured Membranes Fabricated via Vapor-Induced Phase Separation and In Situ Mineralization.

A photocatalytic membrane with significant degradation and antifouling performance has become an important part in wastewater treatment. However, the low catalyst loading on the polymer membrane limits its performance improvement. Herein, we fabricated poly(vinylidene fluoride) (PVDF) and poly(acrylic acid) (PAA) blend membranes with a rough surface via a vapor-induced phase separation (VIPS) process. Then Fe3+ was cross-linked with the carboxyl groups on the membrane surface and further in situ mineralized into β-FeOOH nanorods. The resultant membranes exhibit not only hydrophilicity and underwater superoleophobicity but also favorable separation efficiency and high water flux in oil-in-water emulsions separation. Under visible light irradiation, the membrane can degrade methylene blue (MB) to 95.2% in 180 min. More importantly, the membrane has a significant photocatalytic self-cleaning ability for crude oil with a flux recovery ratio (FRR) as high as 94.1%. This work brings a new strategy to fabricate the rough and porous surface for high loading of the hydrophilic photo-Fenton catalyst, improving the oil/water emulsion separation and antifouling performance of the membranes.

A novel heterogeneous photo-Fenton Fe/Al2O3 catalyst for dye degradation

The activity of heterogeneous photo-Fenton catalysts based on iron and supported on commercial alumina was studied for the degradation of rhodamine B, methyl orange and methylene blue under UV irradiation. The catalysts were prepared by impregnation, drying, and calcination or omitting this last step and referred to as dried or calcined samples. All samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption, diffuse reflectance UV–vis absorption spectroscopy and X-ray photoelectron spectroscopy (XPS). The XRD results revealed that all catalysts showed peaks of α-Al2O3 and FeSO4. The band gap of the catalysts compared with alumina decreased, due to the presences of Fe species which functioned as traps inhibiting the electron-hole recombination. The XPS results revealed the presence hydroxyl groups on the surface and the presence of both Fe3+ and Fe2+ in both catalysts. The photodegradation experiments showed that the heterogeneous photo-Fenton process was much faster compared with the heterogenous photocatalyst on all the tested dyes. The dried Fe/Al2O3 with the presence of H2O2 under UV irradiation showed the best degradation of rhodamine B, methyl orange, and methylene blue at 99.6, 100, and 99.1% at 5, 10, and 5 min, respectively. This could probably be ascribed to a good dispersion of Fe particle species on Al2O3, a low band gap and a proper concentration of hydroxyl groups and sulfate groups on the surface. The scavenger test revealed that the hydroxyl radicals played the main role in the photodegradation of dyes in this process compared with the superoxide radicals and positive holes.

Efficient charge separation of photo-Fenton catalyst: Core-shell CdS/Fe3O4@N-doped C for enhanced photodegradation performance

Effective charge separation and excellent mass transfer are critical for dye photodegradation. Herein, a core-shell cadmium sulfide/ferroferric oxide@ nitrogen doped porous carbon (CdS/Fe 3 O 4 @NPC) photo-Fenton catalyst was prepared by a facile calcination-hydrothermal method. Fe 3 O 4 core not only is favorable to the catalyst recycle because of its super-paramagnetism, but also serves as the redox mediator for collection and consumption of the electrons from CdS, which will improve the separation rate of the photo-generated charge carriers. What's more, Fe 3 O 4 can work as a Fenton catalyst to activate hydrogen peroxide which is generated in situ by CdS. The porous structure of NPC shell with high conductivity can enhance charge separation and facilitate reactant/product mass transfer, thus promoting holes consumption and impeding the photocorrosion of CdS. Benefiting from its structure and functions, the obtained CdS/Fe 3 O 4 @NPC shows wonderful rhodamine B degradation performance (92.0% within 75 min) and still maintains high photo-Fenton catalytic activity after 5 cycles under the visible light irritation. Additionally, the free radical removal experiments show that •O 2 − and •OH are the main active substances of catalysis, which confirms the synergistic effect of photocatalysis and Fenton catalysis. • The core-shell CdS/Fe 3 O 4 @NPC photo-Fenton catalyst was successfully synthesized. • The CdS/Fe 3 O 4 @NPC possesses excellent Photo-Fenton degradation activity of RhB. • The Fe 3 O 4 core catalyzes H 2 O 2 to •OH produced in situ by photocatalysis at neutral pH value. • The mass transfer of NPC shell inhibits the photocorrosion of CdS. • The NPC and Fe 3 O 4 , as electron mediators, effectively accelerate charge separation.

Confined conductive and light-adsorbed network in metal organic frameworks (MIL-88B(Fe)) with enhanced photo-Fenton catalytic activity for sulfamethoxazole degradation

High light adsorption and fast charge separation are crucial for photo-Fenton catalytic activity of MOFs. Herein, bottom-up design was proposed to fabricate polypyrrole (PPyC) nanowires in MIL-88B(Fe) cages as photo-Fenton catalyst for Sulfamethoxazole (SMX) efficient degradation. Pyrrole was prior anchored into MIL-88B(Fe) cluster via Fe-N coordination, and then the additional monomer pyrrole was further triggered bottom-up polymerization in confined cages of MIL-88B(Fe) and formed PPyC@Py-MIL(Fe) composite. These PPyC nanowires were dispersed in Py-MIL(Fe) cages and tightly connected with MOFs clusters via Fe-N bonding. Characterization proved that: (1) Interfacial Fe-N can significantly promote the efficient electron transport from PPyC nanowires to Py-MIL(Fe), enhance optical absorption property, and construct strong Lewis acidic sites and ligand vacancies in PPyC@Py-MIL(Fe). (2) The confined PPyC nanowire via Fe-N connection remarkably promote photo-generated electron-hole separation, Fe2+|Fe3+ redox ability of MOF, and improved photo-electric corrosion ability. As a result, it significantly enhanced the photo-Fenton catalytic performance for SMX degradation. Catalytic oxidation was attributed to the generation of ‧OH species that oxidized 93% SMX in 60 min, showing ultra-rapid degradation and TOC removal rates of 33.7 min−1·mg·g−1 and 8.68 min−1·mg·g−1 respectively, which was about 4–220 times higher than those reported state-of-the-art catalysts. Additionally, the PPyC@Py-MIL(Fe) catalyst showed minimal loss in catalytic activity even after recycling for 10 times, exhibiting good recycling stability compared to many MOFs. Systematic analysis shown that in-situ anchored growth of polypyrrole in confined porous cages of MOF can effectively enhance the catalytic activity and stability of MIL-88B(Fe), and has great development potential applications for photo-Fenton catalytic degradation of organic pollutants.

Visible-light photo-Fenton catalytic MgFe2O4 spinel: Reaction sintering synthesis and DFT study

MgFe2O4 spinel has attracted extensive attention as a photo-Fenton catalyst that can be used to degrade dyes in water under visible light. In this work, the MgFe2O4 spinel synthesized via reaction sintering was first used as a photo-Fenton catalyst to degrade Rhodamine B(RhB) under visible light. Furthermore, the influence of pH, MgFe2O4 spinel catalysts and H2O2 content on reaction activity was systematically investigated. The electronic structure of as-made MgFe2O4 spinel was explored by the DFT theoretical calculations, which revealed the composition of the valence band and conduction band. The prepared MgFe2O4 spinel was a mesoporous material with ferromagnetism, suitable band structure, and good visible light response. Various iron active sites on the MgFe2O4 surface interacted with H2O2 to produce a large amount of hydroxyl radical (·OH), which made the degradation efficiency of RhB reach up to 98.55% and the removal efficiency of TOC was 78.12%. After seven recycles, the efficiency was still above 94%. MgFe2O4 spinel was shown to be a simple-to-recycled, stable, and effective photo-Fenton catalyst with a potential practical application value.

Construction of ultra-stable and Z-scheme Fe-Graphdiyne/MIL-100(Fe) photo-Fenton catalyst with C = C-Fe|O interface for the highly enhanced catalytic degradation of Dinotefuran

High photo-Fenton catalytic activity and stable recycling performance are the main challenges for Fe-based metal–organic frameworks in practical applications of pesticide degradation. Herein, graphdiyne (GDY) with a unique sp/sp2 π-conjugated structure was proposed to composite with MIL-100(Fe) to form the Z-scheme photocatalyst Fe-GDY3@MIL(Fe) for dinotefuran (DTF) degradation. A unique C = C-Fe|O interface was established between Fe-GDY and Fe-MOF owing to the confinement of GDY for anchoring Fe. Fe-GDY3@MIL(Fe) composite having tight C = C-Fe|O interface exhibited the highly conductive Z-scheme structure and dispersed Fe sites, which can efficiently enhance redox ability and accelerate Fe(III)/Fe(II) conversion cycle. Therefore, Fe-GDY3@MIL(Fe) showed 7–80 times of degradation kinetics and 2–5 times of mineralization kinetics compared to the state-of-the-art catalysts under relatively same conditions. Moreover, fast charge separation promoted the chemical stability and photo-corrosion resistance of MIL-100(Fe), which significantly enhanced catalytic stability and life-time.

Boosting Photo-Fenton reactions by amidoxime chelated ferrous iron (Fe(III)) catalyst for highly efficient pollutant control

The maximum exposure of active sites is the key to obtaining high reaction activity for supported metal catalysts. Single-atom metal sites and ultra-small metal clusters have received great attention because of their superior catalytic activities compared to their aggregated counterparts. However, developing high-density metal clusters with high activity and adequate stability remains a major challenge in practical applications. Herein, we demonstrate that highly dispersed and active Fe sites for heterogeneous Photo-Fenton systems can be chelated into graft chains on ultrahigh molecular weight polyethylene (UHMWPE) fibers via radiation-induced graft polymerization (RIGP) and subsequent modification, labeled as U-g-PAO/Fe. The amidoxime chelated Fe(III) catalyst, in which the loading amount of chelated Fe(III) is 24.04 wt%, exhibits remarkably efficient removal of ofloxacin within 35 min by activating H2O2 under visible light irradiation. The catalytic activities and stability of U-g-PAO/Fe were evaluated by the removal of various model organic pollutants and multiple recycles of degradation, demonstrating superior catalytic activities over a wide pH range (2–10) for the activation of H2O2 than a typical Fenton catalyst. Furthermore, the graft macromolecular chains of chelated Fe(III) provide a well-defined reaction microenvironment with maximum atom efficiency. X-ray absorption fine structure (XAFS) and density functional theory calculations (DFT) revealed that the unique active sites [Amidoxime-Fe(OH)(H2O)3]2+ of U-g-PAO/Fe considerably activated H2O2 decomposition under artificial sunlight irradiation. Our study presents a novel idea for the design and synthesis of highly dispersed and reactive Fe-based Photo-Fenton catalysts for practical applications in environmental remediation.