Search Results (366)

Industrial dyes remain a major source of water pollution and pose environmental and human health risks because of their carcinogenic and mutagenic properties. Of these, Congo Red dye shows high toxicity and stability in aquatic environments; therefore, removing it from water bodies is desirable. Among numerous methods, ultrasound-assisted catalysis for dye degradation remains promising. This work investigates the combined effect of ultrasound and an iron oxide (Fe₂O₃) catalyst for degrading Congo Red (CR) dye (a model industrial dye). The characterization of Fe₂O₃ particles was performed through SEM, XRD, and FTIR analyses. CR degradation was performed at 100–600 W ultrasound power, 0–120 min, and with 5–20% (w/v) Fe₂O₃. The ultrasound-driven CR degradation was compared with and without the Fe₂O₃ catalyst. Using ultrasound alone, maximum CR degradation reached 39.30%, while adding Fe₂O₃ (20% w/v) during ultrasonication enabled 93.20% CR degradation in 120 min. The optimized conditions for maximum CR degradation (93.21%) were 600 W, 30 °C, 120 min, and 20% w/v Fe₂O₃. The enhancement was attributed to acoustic cavitation, heterogeneous bubble nucleation on Fe₂O₃ surfaces, improved mass transfer, Fe³⁺/Fe²⁺ redox cycling, and reactive oxygen species generation. Further, the kinetic analysis indicated that the CR degradation followed a pseudo-second-order kinetic model, showing strong agreement with experimental data (R² = 0.96). A detailed mechanism was proposed involving CR adsorption, azo-bond cleavage, aromatic ring hydroxylation, fragmentation, ring opening, and progressive oxidation into smaller intermediates. Overall, the present study demonstrates that ultrasound combined with Fe₂O₃ effectively enhanced Congo Red removal/decolorization under the investigated laboratory-scale conditions. Full article

The demand for materials with flame-retardant and electromagnetic shielding properties has increased research on sustainable and multifunctional composites. Thermoset-based hybrid composites containing Fe₃O₄ and activated carbon obtained from solid waste were investigated for flame retardancy and electromagnetic shielding. Activated carbon produced by pyrolysis of buckwheat hulls (agricultural waste) exhibited a BET surface area of 714.33 m²/g and a conductivity of 69.5 S/m, and was used as a filler to enhance electrical conductivity, while Fe₃O₄ was added to promote electromagnetic absorption. Composites with 1, 3, 5 and 7 wt% activated carbon at a constant 15 wt% Fe₃O₄, together with a complementary series at 5 wt% activated carbon with 10, 15, 30 and 45 wt% magnetite, were characterized by limiting oxygen index and thermal analysis. LOI values clustered between 32.31% (Nov-5-15) and 33.71% (Nov-3-15), a 1.40-percentage-point spread around the 34.31% reference Novolac. The 850 °C char yield peaked at 56.38% (Nov-3-15) and 55.34% (Nov-7-15), with T₅₀% reaching 898 °C and 882 °C, respectively, while DTA replaced the 529 °C Novolac exotherm with endothermic Tmax values of 485–501 °C. Electromagnetic shielding effectiveness over the 8–12 GHz range varied from 2.97 ± 0.3 dB (unfilled Nov-0) to a maximum of 9.19 ± 1.46 dB (Nov-5-45, 5 wt% activated carbon and 45 wt% Fe₃O₄), with an intermediate value of 7.43 dB for Nov-7-15. These hybrids are thus candidate materials for fire-safe phenolic-thermoset applications, where magnetic–dielectric coupling and a percolated char-barrier network govern flame-retardant performance, demonstrating the potential of waste-sourced carbon in sustainable composite production. Full article

Spent titanium chlorinator melt is a potential technogenic source of scandium, but its recovery is complicated by high contents of iron, aluminium and alkali and alkaline-earth chlorides. This study assessed a sequence of hydrochloric acid leaching, Fe(III) reduction with ascorbic acid, sorption on the strong-acid cation exchanger Lewatit MonoPlus SP112H, desorption with acidified ammonium sulfate solution, oxalate precipitation, calcination and an additional column purification. In a scaled-up test, leaching of 4 kg of the spent melt with 5% HCl produced 25.5 L of filtrate containing 475.30 mg Sc. Two-stage sorption recovered 90.9% of the scandium, and the overall desorption degree reached 94.8%. The kinetic data were better described by the non-linear pseudo-second-order model (R² = 0.890–0.938). Precipitation and calcination gave 0.60 g of an intermediate oxide product with 65.0 wt% Sc, and the additional purification 0.45 g of a final oxide product in which X-ray diffraction identified cubic Sc₂O₃ as the predominant crystalline phase; the elemental analysis gave a purity close to 98 wt%. Recovery into the final oxide reached 61.92% of the scandium in the filtrate. Iron co-sorption and scandium losses during the additional purification remained the principal limitations of the process. Full article

In this work, a BiFeO₃/MoS₂ (BM) material was utilized to establish a piezophotocatalytic system under combined visible-light (Vis) illumination and mechanical stirring (MS), which synergistically activated peroxymonosulfate (PMS) toward the oxidation of 4-chlorophenol (4-CP), a representative refractory organic pollutant in water. Under mechanical stirring, the piezoelectric effect in BM generates a polarized electric field that promotes the separation of photogenerated electron–hole pairs, thereby providing more charge carriers for PMS activation and subsequent radical generation. The degradation performance, underlying mechanism, toxicity of degradation products, reusability, and applicability in different water matrices in the BM(1:3)/PMS process were comprehensively evaluated. The results indicated that BM(1:3) exhibited superior performance over other BM ratios (BM(2:1), BM(1:1), and BM(1:2)), achieving 91.6% removal of 4-CP within 30 min at a rotation speed = 1000 rpm, PMS = 2.0 mM, BM(1:3) = 0.5 mg/L, and initial 4-CP = 10 mg/L. Furthermore, water quality parameters exerted notable impacts on 4-CP decomposition. A pH of 4.7 was favorable, and the presence of Cl⁻ enhanced the 4-CP degradation, while HCO₃⁻ and H₂PO₄⁻ suppressed the removal efficiency; SO₄²⁻ and HA showed negligible influence. DFT calculations identified the reactive sites on 4-CP that are prone to attack by various reactive oxygen species (e.g., •O₂⁻, ¹O₂, •OH, and SO₄•⁻), resulting in the transformation of 4-CP through three degradation pathways into smaller organic intermediates, most of which were less toxic than 4-CP. The BM(1:3) catalyst exhibited satisfactory reusability; however, a significant decrease in 4-CP degradation efficiency was observed in the lake water matrix. Overall, the synergy between photocatalysis and the piezoelectric effect in the BM(1:3)/PMS system offers a useful research foundation for the piezophotocatalytic degradation of persistent organic pollutants such as 4-CP. Full article

Tetracycline (TC) is a widely used antibiotic that is frequently detected in rivers, lakes and wastewater. Because TC is poorly removed by conventional biological treatment, its residues can harm aquatic organisms and promote the spread of antibiotic resistance; efficient and low-cost technologies for removing TC from water are therefore needed. In this study, copper smelting slag (CSS), an abundant industrial solid waste, was converted into a catalyst composed of Fe₃O₄ particles loaded on mesoporous silica (denoted Fe₃O₄@MS) via an alkali fusion–hydrothermal method. The catalyst was used to activate peroxymonosulfate (PMS), forming the Fe₃O₄@MS/PMS treatment system for the degradation of TC in aqueous solution. The effects of the main operating parameters (catalyst dosage, PMS concentration, initial pH and reaction temperature) on TC degradation were systematically evaluated. Under the optimized conditions (catalyst 0.5 g/L, PMS 1.0 mmol/L, initial pH 6.5, 25 °C), the Fe₃O₄@MS/PMS system removed 98.70% of 50 mg/L TC within 60 min. Radical quenching experiments and electron paramagnetic resonance (EPR) analysis revealed that TC was degraded through both radical pathways (hydroxyl •OH, sulfate SO₄^•− and superoxide O₂^•− radicals) and a non-radical pathway involving singlet oxygen (¹O₂), with •OH being the dominant reactive species. Nine degradation intermediates were identified by liquid chromatography–mass spectrometry (LC-MS), based on which three degradation pathways were proposed. Toxicity estimation indicated that ring-opening and deamination reactions are the key steps for detoxification. In addition, a life cycle assessment (LCA) across five selected impact categories identified the main environmental burdens associated with catalyst production. Overall, this work demonstrates that CSS-derived Fe₃O₄@MS is an efficient, low-cost and sustainable catalyst for PMS-based antibiotic removal from water, offering a circular-economy approach that couples solid-waste valorization with clean water production. Full article

Sulfamethoxazole (SMX), a persistent sulfonamide antibiotic widespread in aquatic environments, resists conventional water treatment degradation. This work developed a NaOAc/Fe³⁺/O₃ homogeneous ozonation system for SMX abatement. Four comparative reaction groups confirmed significant synergism between trace Fe³⁺ and sodium acetate. Under optimized near-neutral conditions, 96.19% SMX was removed within 30 min with k_obs = 0.107 min⁻¹, outperforming sole O₃, O₃/NaOAc and O₃/Fe³⁺ by 11.0%, 31.0% and 21.9% respectively. Single-factor tests revealed excess Fe³⁺ or acetate suppressed catalytic activity, while alkaline conditions accelerated degradation yet aggravated iron precipitation. Radical quenching and p-CBA probing indicated that acetate coordination did not increase bulk ·OH exposure, while the stronger TEMP-derived TEMPO response after acetate addition was consistent with enhanced ¹O₂-associated oxidation, suggesting that acetate altered the relative contributions of ozone-derived oxidation pathways. Post acetate background deduction, the ternary system achieved higher TOC/COD elimination. Twelve SMX intermediates were identified via LC-MS, with three ring-opening degradation pathways proposed. QSAR toxicity evaluation indicated that most intermediates possessed lower bioconcentration and developmental risks than raw SMX. Overall, the results indicate that weak acetate ligands can alter iron-mediated ozone oxidation pathways, providing a low-dose and economical strategy for antibiotic wastewater treatment. Full article

The corrosion behavior of N80 steel in a simulated coalbed–methane environment was investigated in a high-temperature, high-pressure autoclave. Uniform corrosion and maximum pit depth were quantified by weight-loss measurements and ultra-depth-of-field three-dimensional microscopy, respectively, while SEM, EDS, and XRD were used to characterize the morphology, elemental composition, and crystalline phases of the surface corrosion products. A one-factor-at-a-time design was applied at a constant total pressure of 10 MPa to evaluate the effects of nominal CO₂ partial pressure (0.10–1.00 MPa), nominal O₂ partial pressure (0–0.40 MPa), Cl⁻ concentration (3–187 g/L), and temperature (40–75 °C). Increasing the nominal CO₂ partial pressure raised the uniform corrosion rate from 0.712 to 0.930 mm/a but reduced the maximum pitting corrosion rate from 1.691 to 0.280 mm/a, while FeCO₃-containing surface coverage increased. Increasing the nominal O₂ partial pressure intensified both corrosion modes; at 0.40 MPa, the uniform and maximum pitting corrosion rates reached 1.446 and 2.202 mm/a, respectively, and the corrosion-product layer exhibited extensive cracking and spallation. Increasing the Cl⁻ concentration reduced the uniform corrosion rate from 1.078 to 0.839 mm/a but increased the maximum pitting corrosion rate from 0.474 to 1.807 mm/a, indicating a shift in the principal damage risk from average metal loss to localized penetration. The uniform corrosion rate reached a maximum of 1.516 mm/a at 60 °C, whereas the maximum pitting corrosion rate increased continuously to 2.202 mm/a at 75 °C. XRD identified Fe, FeCO₃, Fe₂O₃, Fe₃O₄, and FeOOH. The persistent Fe substrate reflections, interpreted together with the SEM observations, revealed spatially heterogeneous corrosion-product coverage. These results show that the protective contribution of FeCO₃-containing products depends on their surface coverage and visible integrity rather than on phase presence alone. The findings support stringent oxygen-ingress control, targeted pitting protection in high-salinity environments, and enhanced corrosion surveillance of intermediate- and high-temperature well sections. Full article

This study presents a comprehensive thermodynamic evaluation of several CO₂ conversion pathways, both non-catalytic and catalyst-assisted, using density functional theory (DFT) calculations in Gaussian 16 (B3LYP/6-311++G(d,p)). In the non-catalyzed section, three key routes are examined: hydrogenation (CO₂ + H₂ → CO + H₂O), dry methane reforming, and the reverse water–gas shift (RWGS). For the hydrogenation reaction, the Gibbs free energy change (ΔG) decreases from +0.018 to +0.005 Hartree as the temperature increases from 298.15 K to 1173.15 K, indicating a slight improvement in feasibility but still a high activation barrier of 0.326 Hartree, underscoring the need for catalysis. Dry methane reforming is both exothermic and spontaneous, with ΔG ≈ = −0.049 Hartree at 298.15 K and −0.030 Hartree at 593.15 K; however, operating under harsh conditions may accelerate degradation of reactor materials. In the catalyst-assisted section, copper surfaces and Cu₃M clusters (M = Sc, V, Ni, Cu, Co and Fe) are evaluated alongside two bimetallic catalysts, Fe₂ and Ni₂, under electrochemical CO₂ reduction (eCO₂RR) conditions. Scandium- and vanadium-doped clusters exhibit significant CO₂ adsorption, as evidenced by shifted vibrational frequencies between 800 and 1800 cm⁻¹ that signal C=O bond weakening. Under the evaluated thermobarometric conditions, Ni₂-containing systems displayed lower Gibbs energy values within their own optimized intermediate set and higher entropy values than the corresponding Fe₂-containing set, suggesting greater configurational flexibility and favorable stabilization trends. However, because Fe₂ and Ni₂ systems are chemically different, absolute total energies were not used as a standalone criterion for intrinsic catalytic superiority. Overall, while some non-catalytic routes become thermodynamically more favorable only at high temperature, the explicit inclusion of catalytic models, particularly doped Cu₃M clusters and Ni-containing systems, indicates enhanced CO₂ activation through stronger catalyst–adsorbate interactions, vibrational weakening of C=O bonds, and favorable electronic descriptors. These results suggest that catalytic systems may enable CO₂ conversion under milder conditions, although full kinetic confirmation requires comparative transition state calculations for each elementary catalytic step. Full article

The electrocatalytic reduction of CO₂ into value-added chemicals offers a promising route to mitigate greenhouse gas emissions, yet the uncontrollable structural reconstruction and surface rearrangement of electrocatalysts during operation often lead to severe activity degradation. Herein, we reveal that Bi₂O₂SO₄ (BSO) undergoes an irreversible phase transformation into Bi₂O₂CO₃ (BCO) nanosheets accompanied by the partial reduction of Bi³⁺ to metallic Bi⁰ under cathodic potentials. A series of BCO/BSO heterojunction catalysts with tunable compositions are synthesized via a mild in situ ion-exchange method. To circumvent the detrimental effects of this dynamic reconstruction, we devise a pre-activation strategy that deliberately completes the structural evolution prior to electrocatalysis. The optimized 20%-BCO/BSO heterojunction achieves a remarkable Faradaic efficiency of 98.4% for formate production in a flow cell at elevated potentials, with >95% FE_(HCOOH) over a wide potential window (−0.8 to −1.7 V vs. RHE). In situ infrared spectroscopy elucidates that the reconstructed interface can promote CO₂ adsorption, stabilize the *OCHO intermediate, and facilitate HCOOH desorption. This work provides experimental evidence of the reconstruction behaviour of bismuth-based catalysts and offers a rational design method for constructing structurally stable heterojunction electrocatalysts. Full article

This study investigated the influence of a novel flow–through electro-Fenton (EF) reactor configuration on hydrodynamics and dye removal efficiency using Pt and boron-doped diamond (BDD) anodes coupled with a carbon–PTFE gas diffusion cathode. In this work, an innovative pre–pilot-scale reactor operating in recirculation mode was used to treat 100 mg L⁻¹ Calcon dye solutions in 0.05 mol L⁻¹ Na₂SO₄ at pH 3.0 under electrochemical oxidation (EO) with electrogenerated H₂O₂ (EO-H₂O₂), EF, and Photoelectro-Fenton (PEF) conditions. The effects of applied current density (30–90 mA cm⁻²) and Fe²⁺ concentration (0.25–0.75 mmol L⁻¹) were evaluated through color removal, TOC decay, and identification of oxidation intermediates. The hydrodynamic characterization results revealed flow conditions in a transitional region between laminar and turbulent flow (Re = 3.6 × 10³; Sh = 246). Comparing EF and EO-H₂O₂ processes, when Fe²⁺ was added to the solution, it significantly accelerated discoloration and, consequently, dye degradation in the former, while the absence of Fe²⁺ resulted in slower discoloration kinetics, reaching only 85.8% color removal after 180 min in the latter. The best performance was obtained with 0.50 mmol L⁻¹ Fe²⁺ in EF, achieving >98% discoloration. Among the investigated processes, PEF exhibited the highest mineralization efficiency. TOC removals using BDD as the anode efficiently reached high mineralization levels of 83.88%, 86.99%, and 93.38% for EO-H₂O₂, EF, and PEF, respectively, while Pt as the anode achieved 81.80%, 85.14%, and 91.63%. Overall, the BDD/PEF system showed the best degradation and mineralization performance. The proposed reactor was designed at the pre-pilot scale and incorporates vertical recirculation flow with hydrodynamic optimization, enabling efficient mass transfer and improved oxidant generation. The study provides practical insights into the reactor engineering aspects required for the future scale-up of EF technologies. Full article

We outline an intermediate step toward a semirelativistic BSR–RMT interface by using inner-region structure information generated with the B-spline R-matrix (BSR) method as the input to the Seaton/Badnell STGF/STGBF outer-region asymptotic codes used in R-matrix photoionization calculations. The long-term goal is to exploit the compact, nonorthogonal, term-dependent target descriptions available in BSR for time-dependent R-matrix calculations with the R matrix with time dependence (RMT) method, especially for processes sensitive to semirelativistic and spin-orbit effects. To probe these effects, we consider the ground-state photoionization of Ne⁸⁺, Ar¹⁶⁺, Fe²⁴⁺, and Kr³⁴⁺, focusing on resonance structures and the singlet-triplet separation of the predominantly ${2s2p}^3{P}^o$ and ${2s2p}^1{P}^o$ autoionizing states and their spin-orbit mixing. For Fe²⁴⁺, we also analyze higher resonances and the region between the ionic thresholds, with R-matrix I (RM-I) calculations using Badnell’s version for comparison. The BSR results agree well overall with the available Iron Project data and with the NIST separations between the predominantly ${2s2p}^3{P}^o$ and ${2s2p}^1{P}^o$ levels. Since semirelativistic RMT currently uses RM-I input; the successful interfacing of BSR inner-region data with STGF/STGBF codes that likewise use RM-I input represents a direct precursor to semirelativistic BSR–RMT capability. Full article

Laser powder bed fusion (LPBF) produces microstructural anisotropy that influences hydrogen transport and passive film stability, yet the mechanistic relationship between build orientation, passive film chemistry, and corrosion behavior remains insufficiently understood. This study investigates how LPBF build orientation governs hydrogen-assisted passive film degradation by correlating electrochemical behavior with passive film chemistry. Additively manufactured 316L stainless steel specimens were fabricated in two build orientations, horizontal (0°) and vertical (90°), and subjected to electrochemical hydrogen charging for durations ranging from 2 to 36 h. Corrosion behavior was evaluated using open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), and potentiodynamic polarization (PDP), while X-ray photoelectron spectroscopy (XPS) was employed to characterize hydrogen-induced changes in passive film chemistry. The electrochemical response showed that hydrogen charging progressively reduced the corrosion resistance of both build orientations. However, the degradation exhibited a non-monotonic dependence on charging duration, with intermediate charging durations suggesting transient repassivation before renewed deterioration during prolonged hydrogen exposure. EIS analysis revealed a substantial decrease in the fitted total resistance (R_total = R_ct + R_po), from 1.44 to 0.27 kΩ cm² for the 0° specimens and from 4.23 to 0.55 kΩ cm² for the 90° specimens. Potentiodynamic polarization showed that prolonged hydrogen charging increased the corrosion current density from 20.99 to 98.91 μA cm⁻² for the 0° specimens and from 0.79 to 46.86 μA cm⁻² for the 90° specimens. XPS analysis revealed progressive depletion of protective oxide species (Fe₂O₃, Cr₂O₃, Mo oxides, and lattice oxygen) together with enrichment of hydroxide-rich species, resulting in a lower O²⁻/OH⁻ ratio and transformation of the passive film into a more porous and less protective surface layer. These chemical changes were more pronounced in the 90° build orientation and were consistent with the greater reduction in passive film stability observed from the electrochemical measurements. The combined electrochemical and XPS analyses establish that LPBF build orientation governs hydrogen-assisted corrosion through its influence on microstructural anisotropy, hydrogen transport, passive film chemistry, and the resulting electrochemical response, providing mechanistic insight into the corrosion behavior of additively manufactured 316L stainless steel in hydrogen-containing environments. Full article

The structure–activity relationship of three oxyphosphonate inhibitors differing in heteroatom type (C, N, S) was examined to clarify their influence on the pitting corrosion resistance of ferritic–martensitic steel EP-450 in chloride media. Gravimetric tests in 10% FeCl₃, supported by surface microscopy and adsorption analysis, showed that EP-450 is highly susceptible to localized attack, with pits nucleating preferentially at carbide-enriched, chromium-depleted regions. Addition of dimethyl(1-hydroxycyclohexyl)phosphonate reduced the corrosion rate from 49 to 33 mm/year at 2.0 g/L, corresponding to ≈33% protection, while the nitrogen-containing dimethyl[1-(2-ethoxyethyl)-4-hydroxypiperidin-4-yl]phosphonate produced the largest decrease in mass loss, exceeding a 55% reduction under identical conditions. The sulfur-bearing dimethyl(4-hydroxytetrahydro-2H-thiopyran-4-yl)phosphonate afforded an intermediate effect. Adsorption analysis for the cyclohexyl derivative suggested mixed physisorption–chemisorption with limited surface coverage, while heteroatom substitution (N or S) is consistent with a change in adsorption configuration and interfacial packing that can yield a more compact protective layer. The observed inhibition efficiency increased in the sequence C < S < N, which is interpreted empirically in terms of heteroatom-dependent adsorption geometry and film integrity rather than conjugation-driven activation of the P=O group. Full article

Mononuclear nonheme iron(IV)–oxo species supported by mixed nitrogen–sulfur (N/S) ligands remain scarce, despite the prevalence of sulfur donors in biological iron sites and their expected impact on ferryl reactivity and catalyst design. In this work, a seven-coordinate iron(II) complex, [(N₃S₂)Fe^II(ClO₄)₂], bearing a rigid 15-membered N₃S₂ macrocycle, is shown to rapidly generate a mononuclear nonheme Fe^IV=O intermediate upon reaction with m-chloroperbenzoic (m-CPBA) acid in acetonitrile. The Fe^IV=O species forms within ≤2 s and is thermally persistent (t₁/₂ = 4.3 h at 25 °C), albeit in partial yield (~39% Fe^IV=O by Mössbauer spectroscopy), placing it in an intermediate regime between highly reactive but short-lived ferryl species and more inert, long-lived analogues. The intermediate is characterized by Mössbauer spectroscopy (δ = 0.35 mm s⁻¹, ΔE_Q = 0.90 mm s⁻¹, Γ_FWHM = 0.30 mm s⁻¹, relative area = 39.4%), EPR silence, a UV–vis absorption band at 428 nm, and cryogenic high-resolution ESI–MS (m/z 223.510, (N₃S₂)Fe^IV=O²⁺). Stopped-flow kinetic studies reveal saturation behavior that is well described by a pre-equilibrium oxidant-association model and subsequent O–O bond activation, with apparent activation parameters of ΔH^‡ = 17.7 kJ mol⁻¹ and ΔS^‡ = −155 J mol⁻¹ K⁻¹, indicating a highly ordered transition state within the seven-coordinate N₃S₂ framework under the conditions employed. Functionally, the Fe^IV=O species mediates clean oxygen-atom transfer to triphenylphosphine (k₂ = 8.1 × 10⁻² M⁻¹ s⁻¹) with an effective turnover number of ~12 after correction for the Fe^IV=O yield, establishing that this mixed N/S platform is catalytically competent under mild conditions, though less reactive than state-of-the-art all-nitrogen systems. Collectively, these findings identify the seven-coordinate N₃S₂ macrocycle as a mixed-donor platform that moderately extends ferryl lifetime while retaining measurable oxo-transfer reactivity, providing mechanistic guidance for the development of nonheme iron oxidation catalysts that incorporate sulfur donors. Full article

The increasing prevalence of multiclass pesticide residues in aquatic environments poses a significant threat to ecosystems and human health. To address this challenge, magnetic Fe₃O₄@Co₅Al-LDH nanoparticles were synthesized as high-performance, easily recoverable catalysts for the peroxymonosulfate (PMS)-mediated degradation of epoxiconazole, atrazine, and metalaxyl. Under optimized conditions (pH 7.0, 35 mg catalyst, and 4.0 mM PMS), the system achieved 100% degradation of the three coexisting pesticides within 15 min. Quenching experiments and electron paramagnetic resonance (EPR) spectroscopy confirmed that SO₄⁻ and ^•OH radicals were the primary reactive species driving the process. Liquid chromatography–mass spectrometry (LC-MS) analysis identified four intermediates for epoxiconazole, three for atrazine, and four for metalaxyl, facilitating the proposal of distinct degradation pathways. The degradation mechanism revealed that electron transfer between Fe/Co and PMS promoted the generation of reactive oxygen species, leading to dechlorination, hydroxylation, and dealkylation of the pesticides transiently adsorbed on the surface of Fe₃O₄@Co₅Al-LDH. In summary, this study demonstrates that Fe₃O₄@Co₅Al-LDH is an easily recoverable, reusable, and cost-effective catalyst for the simultaneous remediation of complex pesticide mixtures in water. Full article