Heterogeneous Fenton-like Catalyst Research Articles

Hierarchical microsphere encapsulated in graphene oxide composite for durable synergetic membrane separation and Fenton-like degradation

As a typical advanced oxidation process, persulfate-based heterogeneous Fenton-like reaction has gained widespread attention in removing persistent harmful organic pollutants via the generation of reactive radicals. Nevertheless, persulfate having an inefficient decomposition of the target contaminants and common powdery counterparts causing secondary pollution. Herein, we first design and fabricate a novel metal-organic frameworks (MOFs) derived cobalt-carbon based heterogeneous Fenton-like catalyst (Co@NCNT-MS) with hierarchical structure, the systematic characterization demonstrated that powder catalysts were successfully prepared and the catalyst possessed a favorable degradation capacity of tetracycline (TC), which could be contributed by its particular hierarchical urchin-like structure with abundant active sites and that both radical (·SO4−, ·OH, and ·O2−) and nonradical (1O2) species have been involved in the process. Then, this hierarchical heterogeneous catalyst was encapsulated in Graphene oxide (GO) by facile vacuum filtration to form a robust composite membrane. And the obtained membrane shows good application prospects as it exhibits excellent separation and catalytic degradation properties in removal of anionic dye, cationic dye, and persistent refractory tetracycline. It is speculated that these excellent results could be primarily attributed to the domain effect of micro-nano channels in the membrane on low-life active components, pollutions, and PMS. More than that, the as-prepared membrane displayed excellent stability with continuous removal of TC with high efficiency above 90% and a steady flux around 40 L·m−2·h−1 under 24 h sequential filtration mode. It is promising that this membrane could potentially be used for effectually treating complex wastewater systems with persistent organic contaminants in environmental pollution cleaning up.

Ultrasonic-assisted degradation of a methylene blue using CuCo2O4 as a heterogeneous Fenton-like catalyst

In this study, a copper cobaltite nanostructure was prepared as a non-ferrous heterogeneous Fenton catalyst using a one-step solvothermal method. The prepared nanocatalyst was characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), infrared spectroscopy (FT-IR) and energy-dispersive X-ray spectroscopy (EDS). The prepared CuCo2O4 exhibited outstanding activity for the degradation of methylene blue (MB) in aqueous solutions under ultrasonic irradiations. The degradation efficiency of MB was only 27.4 % in the absence of catalyst, whereas it reached more than 95.0 % in the presence of the CuCo2O4 after 60 min of ultrasonic irradiation. The trapping experiments with two radical scavengers (tert-butanol and chloroform) showed that both hydroxyl and superoxide radicals are generated during the decomposition of H2O2 and played important roles in oxidation of MB. The prepared nanocatalyst demonstrated good catalytic stability over three successive runs, without any remarkable decrease in catalytic activity.

A novel Fenton-like catalyst of Ag3PO4/g-C3N4: Its performance and mechanism for tetracycline hydrochloride degradation in dark

Heterogeneous Fenton-like reaction has been extensively investigated for degradation of organic pollutants for waste treatment due to the formation of highly aggressive hydroxyl radicals from hydrogen peroxide. However, most heterogeneous Fenton-like catalysts still worked well under acid conditions/or with the help of light irradiation/ electrical field, which limits their applications. Here, a novel Fenton-like catalyst of Ag3PO4/g-C3N4was used for degradation of tetracycline hydrochloride (TCH, a typical emerging aqueous pollutant) for the first time in a wide pH value range (4.04–9.08) in dark. The results showed that it could effectively activate H2O2to generate ⋅OH and ⋅O2– radicals in dark, which could oxidize the target pollutant in the all testing pH value range. It also showed a good stability in repeating test. The results of characterizationsand theory calculation revealed a strong electronic interaction between Ag3PO4and g-C3N4improving the electron densities around Ag and O atoms in Ag3PO4on the interface, which benefited the formation of active species. This work is expected to provide an insight for the design and fabrication of the novel highly-efficient Fenton-like catalysts for purification of waste water in a wide pH range.

Calcined Aluminum Sludge as a Heterogeneous Fenton-Like Catalyst for Methylene Blue Degradation by Three-Dimensional Electrochemical System

Calcined Aluminum Sludge as a Heterogeneous Fenton-Like Catalyst for Methylene Blue Degradation by Three-Dimensional Electrochemical System

Design and synthesis of BiVO4@CuOx as a photo assisted Fenton-like catalyst for efficient degradation of tetracycline

The rational design and fabrication of stable and efficient heterogeneous Fenton-like catalyst is of great significance for wastewater treatment, but is also fraught with obstacles. In this paper, we synthesized BiVO4@CuOx composite catalyst through a simple hydrothermal method and in situ chemical deposition. The degradation of tetracycline (TC) is carried out as a main model pollutant through Fenton reaction assisted by light irradiation. The prepared catalyst exhibits superb efficiency and satisfactory stability for the degradation of TC owing to the synergistic effect of light irradiation and decomposition of H2O2. The factors influencing the degradation such as catalyst dosage, H2O2 concentration and initial pH value are also investigated. Moreover, a possible mechanism of degradation of TC in BiVO4@CuOx/H2O2 system is discussed based on the premise that •OH, •O2− and h+ are demonstrated to be the main active species via in-situ ESR measurements. This work puts forward a new suggestion for designing and synthesizing photo assisted Fenton-like catalyst to remove organic contaminants in sewage.

Steel Scale Waste as a Heterogeneous Fenton-like Catalyst for the Treatment of Landfill Leachate

Sustainable industrial processes are essential for better economic growths and for the conservation of the environment. Steel scale waste (SSW) is a byproduct of steel production containing oxides in a large quantity; presently, it is mainly disposed off to landfill. However, being a rich iron source, it appears attractive for processes based on Fenton technology that is catalyzed by iron species. This study originates from the idea of exploiting waste (steel waste) to be used in the treatment of liquid waste, in the perspective of more sustainable processes within a circular economy. Herein, we have employed steel scale waste as a heterogeneous Fenton-like catalyst for the treatment of landfill leachate, changing its profile from a waste to a reagent. To the best of our knowledge, this study is the first attempt to utilize steel scale for the treatment of landfill leachate. At mild conditions, SSW successfully removed about 75% of the recalcitrant organic loading from landfill leachate. This study highlighted that SSW is a promising material for the treatment of heavily polluted wastewater streams. These findings appear extremely important in a circular economy perspective because steel scale waste is produced in huge quantities and could be effectively used as a catalyst in a highly polluted liquid waste treatment process.

Ultrasound-assisted heterogeneous Fenton-like process for methylene blue removal using magnetic MnFe2O4/biochar nanocomposite

In this study, a MnFe2O4 nanocomposite (MnFe2O4/BC) using biochar as the carrier was prepared by a simple hydrothermal method, and then an ultrasound-assisted heterogeneous Fenton-like process was used to catalytically degrade methylene blue (MB). The catalyst was characterized by SEM, TEM, BET, XRD, FTIR, VSM, and XPS. The results showed that spherical MnFe2O4 was successfully loaded onto the biochar surface. The introduction of biochar inhibited the aggregation of MnFe2O4 and greatly increased the specific surface area from 41.4 m2/g to 95.1 m2/g. When using the MnFe2O4/BC composite as an ultrasound-assisted heterogeneous Fenton-like catalyst, 95% of MB (20 mg/L) was degraded at pH = 5 in the presence of 15 mmol/L H2O2 in 20 min, exhibiting a reaction rate constant of 0.09 min−1 much larger than that over MnFe2O4 (0.00995 min−1). This efficiency may be due to the synergistic effect of ultrasound and MnFe2O4/BC, which simultaneously induced the generation of reactive radicals and increased the mass transfer rate at the solid–liquid interface. Compared with other catalysts, the degradation and mineralization levels of MB over MnFe2O4/BC catalyst are greatly improved. These results indicate that MnFe2O4/BC has significant potential for use as a highly efficient and low-cost catalyst for ultrasound-assisted heterogeneous Fenton-like systems.

Effect of magnesium ferrite doping with lanthanide ions on dark-, visible- and UV-driven methylene blue degradation on heterogeneous Fenton-like catalysts

The catalytic behavior of magnesium ferrites doped with lanthanide ions (La3+, Ce3+, Sm3+, Gd3+, and Dy3+) on Methylene Blue (MB) degradation using Fenton process was studied. A slow increase in cubic Fd3m crystalline structure parameters and increase in crystallite size of doped samples magnesium ferrites were observed. A dramatic decrease in catalytic activity of catalysts obtained at 600 °C as compared to catalysts obtained at 300 °C was explicitly observed and this was grossly attributed to the elimination of surface hydroxyl groups as ascertained by FT-IR analysis. The initial magnesium ferrite demonstrated the highest catalytic activity under dark- (kˈ 0.0555 min−1) and visible-light (kˈ 0.1029 min−1) conditions. Catalytic efficiency of the lanthanides doped catalysts under UV-irradiation in accordance with the maximum appearance rate constant kˈ decreased in the following order Ce3+ > Dy3+ > La3+ ≈ MgFe2O4 > Sm3+ > Gd3+. The most active ferrites provided up to 99% of MB degradation in 60 and 20 min for visible- and UV-driven Fenton processes. Findings obtained from this study were observed to be competitive with other heterogeneous Fenton catalysts.

Facile one-step synthesis of 3D honeycomb-like porous chitosan bead inlaid with Mn[sbnd]Fe bimetallic oxide nanoparticles for enhanced degradation of dye pollutant

Developing a sustainable, efficient and recyclable heterogeneous Fenton-like catalyst is important to wastewater treatment. Herein, well-dispersed MnO2 and Fe3O4 nanoparticles inlaid in chitosan beads (MnO2-Fe3O4/CH) was firstly fabricated and employed in the degradation of methylene blue (MB). The bead was prepared via a facile one-step method by dropwise addition of chitosan-metal salt solution into alkaline solution. Comparing with monometallic chitosan beads (MnO2/CH, Fe3O4/CH) and naked MnO2-Fe3O4, MnO2-Fe3O4/CH displayed significantly higher activity for MB degradation with the assistance of hydrogen peroxide (H2O2), finally removing 96.8% MB under the optimal conditions (50 mg L−1 MB, 4.0 g L−1 catalyst, 30 g L−1 H2O2, pH = 7, 60 min). Based on a series of characterizations, the large surface area (60.1 m2 g−1), well-developed porosity (0.3 cm3 g−1), and intensified electron transport of MnO2-Fe3O4/CH consequently enhanced the catalytic performance via a synergistic effect. Because the specific porous structure of MnO2-Fe3O4/CH facilitated the adsorption/diffusion of reactants and exposure of active sites. Meanwhile, the electron transfer from Mn3+ to Fe3+ accelerated the Fe3+/Fe2+ cycle, which favored the production of dominant reactive species hydroxyl radical for MB degradation. Besides, the magnetic beads could be easily collected from the solution and reused for five times with a negligible leaching.

Fe3O4-NPs/orange peel composite as magnetic heterogeneous Fenton-like catalyst towards high-efficiency degradation of methyl orange.

Magnetite nanoparticles (Fe3O4-NPs)/orange peel (MOP) composite was prepared via one-step in-situ co-precipitation method as magnetic heterogeneous Fenton-like catalyst. The properties of MOP were characterized by scanning electron microscopy, transmission electron microscopes, Brunauer-Emmett-Teller, X-ray diffraction, Fourier-transform infrared, thermogravimetric analysis and X-ray photoelectron spectroscopy technologies. Its Fenton-like catalytic responses towards removal of methyl orange (MO) were investigated, in which the effects of initial dye concentration, pH, temperature and hydrogen peroxide dosage were studied. The MO degradation ratio up to 98.0% was obtained within 20 min in optimized conditions. The catalyst showed excellent catalytic stability exhibiting nearly 90% degradation ratio in the 10th cycle within 20 min, whereas pure Fe3O4-NPs showed only 62.5% in this stage. Due to the stabilization of complexing orange peel hydroxyl to iron oxide in the composite and its magnetic separation property, MOP composite exhibits excellent Fenton-like catalytic performance, which offers great prospects for low-cost and high-efficiency organic dye wastewater treatment.

Heterogeneous fenton-like degradation of amoxicillin using MOF-derived Fe0 embedded in mesoporous carbon as an effective catalyst

The presence of the antibiotics in wastewater and drinking water is causing increasing concern around the world, thereby an advanced sustainable technology needs to be developed to remove the antibiotics from water resources. In this study, Metal-organic frameworks (MOFs) derived zero-valent iron embedded in the carbon matrix structure named FMC is prepared by a direct pyrolysis of Fe-based metal organic framework. FMC is used as a heterogeneous Fenton-like catalyst to degrade amoxicillin (AMX) based on the oxidation and degradation reactions. FMC had the strengthened catalytic performance for amoxicillin elimination with high mineralization efficiency (60.41%), which was evaluated over various experimental conditions. The role of reaction in FMC/H2O2 system was identified, suggesting amoxicillin was eliminated by the attack of hydroxyls radicals (·OH). The carbon structures can facilitate the passage of electrons and boost the contact of zero valent iron and Fe2+ species on FMC surface with H2O2, resulting in the accelerated production of ·OH and high removal efficiency of amoxicillin. By defining reactive oxidizing species and degradation intermediates, the plausible degradation pathways of amoxicillin have been inferred. This study revealed that FMC/H2O2 system has high AMX degradation efficiency and decent recyclability.

Degradation of ciprofloxacin using hematite/MOF nanocomposite as a heterogeneous Fenton-like catalyst: A comparison of composite and core−shell structures

A novel strategy was described to fabricate hematite-MOF materials with morphologies (core-shell) and (composite) as an efficient peroxymonosulfate (PMS) activator for degrading ciprofloxacin (CIP) antibiotics. First, α-Fe2O3 nanoparticles (NPs) with a size distribution range of 80 nm were prepared by surfactant-assisted reflux method. Then, cobalt-based metal-organic framework (ZIF-67) was grown onto the α-Fe2O3 NPs with ultrasonic and solvothermal method, which can control the nanostructures morphology. The physicochemical properties of these nanostructures were probed by ATR-IR, WA-XRD, FESEM, VSM, TEM, and EDS spectroscopy. The results showed that all the added CIP (20 ppm) antibiotics were completely degraded in 30 min in the α-Fe2O3/ZIF-67 (0.10 g/L) and PMS (0.20 g/L) system with rate constant of 0.130 min−1. To validate the merits of the α-Fe2O3/ZIF-67, α-Fe2O3@ZIF-67 core-shell nanostructures were also applied under similar conditions. The findings demonstrated that Co/Fe species within α-Fe2O3/ZIF-67 composite catalyzed PMS synergistically to the formation of the OH and SO4− and 1O2 for CIP degradation. Furthermore, α-Fe2O3/ZIF-67 showed good recyclability enabling facile separation of the catalyst from reaction mixtures using an external magnet. The current protocol can be a useful criterion in designing various Magnetic-MOF composites with controlled morphologies for environmental remediation.

A stepwise processing strategy for treating highly acidic wastewater and comprehensive utilization of the products derived from different treating steps

A stepwise processing strategy, including initial neutralization, chemical mineralization, and complete neutralization treating steps, was developed to effectively treat and utilize the highly acidic wastewater derived from titanium dioxide production. Approximately 94.6% of SO42−, 100% of Fe, and most of other metals were recovered to produce white gypsum, schwertmannite, and Fe0/Fe3O4@biochar (Fe0/Fe3O4@BC) composite in the corresponding treating steps. The resulting effluent with neutral pH and a small amount of metal ions could be discharged to general sewage treatment plant for further processing. Schwertmannite was applied as a heterogeneous Fenton-like catalyst to stimulate H2O2 to produce active radicals for effective degradation and mineralization of methyl orange (MO) in solution. The MO removal of 100% and total organic carbon removal of 91.1% were achieved in schwertmannite/H2O2 reaction system, and schwertmannite exhibited good stability and reusability. Fe0/Fe3O4@BC composite was applied to remove Cr(VI), with the adsorption capacity of 67.74 mg g−1. The removal of Cr(VI) using Fe0/Fe3O4@BC composite was a chemisorption process, including the adsorption of Cr(VI), reduction of Cr(VI) to Cr(III), and co-precipitation of Cr(III)/Fe(III) oxides/hydroxides. This stepwise treating strategy is a promising technology for effective treatment of highly acidic industrial wastewater and comprehensive utilization of the related products.

Designing a Feasible Phenol Destruction Process Using LaM1−xCuxO3 (M = Co, Cr, Fe) Perovskites as Heterogeneous Fenton-Like Catalysts

Phenol is one of the most toxic and carcinogenic oxygenated organic compounds, which is often found in wastewater of various industries. Therefore, design of efficient phenol degradation method becomes crucial. B-site substitution into perovskite structure generates synergistic effects in its structure which enhances catalytic properties. However, to effectively design an economically feasible process, substitution of cheap and catalytically active B-site metal elements becomes significant. In view of this, three perovskite-type oxides with chemical formula LaM0.5Cu0.5O3 (M = Co, Cr, Fe) were synthesized and characterized in this work. Furthermore, their application in a feasible phenol oxidation process has been reported. The XRD and XPS analysis results demonstrate successful B-site substitution of transition metal elements in perovskite structure. Remarkably high BET surface areas were obtained for all three catalysts (32–47 m2/g). The results of catalytic activity tests constructively reveal that LaCo0.5Cu0.5O3 is superior when compared with the other two catalysts. Highest TOC removal and best catalytic performance was exhibited by all the catalysts at 90 ℃, atmospheric pressure, 1 g/l catalyst loading and 700 rpm stirring speed. The reaction was successfully completed with hydrogen peroxide concentration less than the stoichiometric amount required for the reaction. The order of catalytic activity is LaCo0.5Cu0.5O3 > LaCr0.5Cu0.5O3 > LaFe0.5Cu0.5O3. This order of catalytic activity of the prepared catalysts can be attributed to high amount of lattice oxygen provided by LaCo0.5Cu0.5O3 catalyst, and the same conclusion can be drawn from the XPS analysis. This suggests that excellent catalytic performance can be attained at low costs for phenol oxidation process.

Copper Loaded Hydroxyapatite Nanoparticles as eco‐friendly Fenton-like catalyst to Effectively Remove Organic Dyes

In this study, natural hydroxyapatite (NHAp) was synthesized by the dissolution of phosphate rock in acidic medium and precipitated via basic solution. Then, a series of copper loaded NHAp (Cu/NHAp) were prepared using ion exchange method and employed as a novel heterogeneous Fenton-like catalyst for degradation of a toxic organic compound. The Cu/NHAp materials have been characterized by different physico-chemical techniques including XRD, XPS, FT-IR, Raman & UV–vis spectroscopies, NMR 31P, SEM, TEM and nitrogen adsorption-desorption methods. The materials exhibit a high catalytic activity for the degradation of methylene blue in the presence of H2O2 as green oxidant under basic medium. Moreover, the effects of different parameters, including pH, H2O2 concentration, catalyst loading, initial dye concentration, and temperature on the degradation kinetics were investigated and discussed in detail. Furthermore, based on the results obtained by radical quenching experiments and electron paramagnetic resonance (EPR), it was shown that hydroxyl radicals were the main reactive species responsible for MB degradation. Finally, TOC analysis, catalyst recyclability and stability confirmed that copper loaded hydroxyapatite might be an alternative Fenton-like catalyst towards organic pollutants degradation and environmental remediation.

FeS2-Fe1-xS heterostructure as a high-efficient Fenton-like catalyst for ultrafast degradation of orange II

It is a challenge to develop heterogeneous Fenton-like catalysts with excellent performance and stability in the field of wastewater treatment. In this work, the FeS2-Fe1-xS heterostructure catalyst was prepared by solvothermal method through adding cobalt element to change the particle nucleation process and inhibit the transformation process of pyrrhotite (Fe1-xS) phase to pyrite (FeS2) phase. Then, a series of experiments were devised to clarify the catalytic activity of FeS2-Fe1-xS heterostructure. The degradation experiments exhibited that 99.9% degradation efficiency was achieved for 30 mg/L orange II solution within 15 min at the conditions of 0.2 g/L FeS2-Fe1-xS, 2 mM H2O2 and pH = 3.0. In addition, the reusability of the FeS2-Fe1-xS catalyst was also investigated and the result displayed that degradation efficiency of orange II can reach 95.2% after eight cycles. The degradation of orange II was enhanced by Fenton reaction between FeS2-Fe1-xS and dissolved oxygen, which could smoothly release Fe2+ and Fe3+ for the activation of H2O2 to produce more hydroxyl radicals. Finally, the degradation pathway of orange II was proposed by detecting intermediates produced in FeS2-Fe1-xS/H2O2 photo-Fenton-like system by liquid chromatography-mass spectrometry (LC-MS). In short, FeS2-Fe1-xS is a promising catalyst for removing the organic pollutants from solutions.

Heterogeneous WO3/H2O2 system for degradation of Indigo Carmin dye from aqueous solution

In this work, tungsten oxide crystals (WO3), with different sizes and morphologies were prepared using the reflux condensation method. Tungsten oxide crystals were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Then, the particles were used as a heterogeneous Fenton-like catalyst in the presence of green oxidant H2O2 for Indigo Carmin (IC) dye degradation. The efficiency of the coupling WO3/H2O2 showed at 600 °C, that it was possible to remove about 90% of the initial color of IC after 120 min in a batch reaction at 65 °C. Moreover, the coupling maintained high activity after four continuous cycles when tungsten oxide particles were recorvered.

Catalytic Oxidation of Tartrazine in Aqueous Solution Using a Pillared Clay with Aluminum and Iron

In this work, pillared bentonite with Al−Fe (Al−Fe−PILC) was synthesized and used as a heterogeneous Fenton-like catalyst in the oxidation of tartrazine azo-dye in an aqueous solution. The modification of bentonite with the Al-Fe mixed system in a concentrated medium, with ultrasound assisted intercalation was carried out, and the obtained catalyst was characterized by XRF, XRD, and N2 adsorption at 77 K. The oxidation of tartrazine with Al−Fe−PILC, using different amounts of H2O2, expressed as a multiple (1, 3, 6, and 9) of a stoichiometry amount required to completely oxidize the dye was evaluated. The reaction of catalytic wet peroxide oxidation (CWPO) of the dye with 400 mg of Al−Fe−PILC and 6 times the stoichiometric amount of H2O2 at 25 °C, reached 98.2±1.8% of decolorization, 51.9±1.9% of TOC removal and 71.5±1.8% of TN removal. Results of this study show that the oxidation of tartrazine increased with the amount of H2O2 up to a certain limit. This oxidation process can be considered as an alternative for treating wastewater containing azo-dye because the reaction takes place under mild experimental conditions (room temperature and atmospheric pressure). Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Yolk-shell Fe3O4@MOF-5 nanocomposites as a heterogeneous Fenton-like catalyst for organic dye removal

Yolk-shell Fe3O4@MOF-5 nanocomposites were synthesized by utilizing a simple solvothermal method. The physicochemical properties of the yolk-shell Fe3O4@MOF-5 nanocomposites were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) and vibrating sample magnetometer (VSM) methods. The nanocomposites had a catalytic yolk, a hollow cavity and a porous shell. The nanocomposites had relatively high specific surface area of 203 m2 g−1 and showed superparamagnetic property. The catalytic activities of the yolk-shell Fe3O4@MOF-5 nanocomposites were evaluated by using methylene blue dye as a model pollutant. It is demonstrated that the yolk-shell Fe3O4@MOF-5 nanocomposites as a heterogeneous Fenton-like catalyst exhibited excellent catalysis since the internal cavity provided a relatively stable micro-environment for the reaction of the active ·OH radicals and the pollutants on the basis of the confinement effect. Furthermore, the yolk-shell Fe3O4@MOF-5 nanocomposites could be lightly separated from the pollutant solution by an external magnetic field and maintained good catalytic activity after five recycles, indicating the good stability of the nanocomposites.

Facile pH-controlled synthesis of MnWO4 nanoparticles and nanorods and their heterogeneous Fenton-like catalytic activity

MnWO4 nanoparticles and nanorods were respectively synthesized in the different pH of reactant solutions by a hydrothermal method. It was found that the pH of reactant solutions not only determined the purity and morphology of the synthesized MnWO4, but also determined the sizes of MnWO4 nanorods. MnWO4 nanoparticles had bigger specific surface area than the obtained different sizes of MnWO4 nanorods. For the degradation of aqueous methylene blue (MB), MnWO4 nanoparticles showed both larger adsorption capacity and higher Fenton-like catalytic activity as compared with MnWO4 nanorods. The mechanism study results demonstrated that the Fenton-like catalytic activity of MnWO4 is predominantly from WO42–. This study suggests that insoluble metal tungstates are a kind of promising heterogeneous Fenton-like catalysts.