Search Results (186)

Hydrogen peroxide (H₂O₂) is a key oxidant for green chemical processes, yet its catalytic utilization and activation efficiency remain limited by material instability and uncontrolled radical release. Here, we report a dual-functional, hollow conductive polymer nanostructure that enables selective modulation of H₂O₂ reactivity through interfacial physicochemical design. Hollow polypyrrole nanospheres functionalized with carboxyl groups (PPy@PyCOOH) were synthesized via a one-step Fe²⁺/H₂O₂ oxidative copolymerization route, in which H₂O₂ simultaneously served as oxidant, template, and reactant. The resulting structure exhibits enhanced hydrophilicity, rapid redox degradability (>80% optical loss in 60 min (82.5 ± 4.1%, 95% CI: 82.5 ± 10.2%), 10 mM H₂O₂, pH 6.5), and strong electronic coupling to reactive oxygen intermediates. Subsequent tannic acid–copper (TA–Cu) coordination produced a conformal metal–polyphenol network that introduces a controllable Fenton-like catalytic interface, achieving a 50% increase in ROS yield (1.52 ± 0.08-fold vs. control, 95% CI: 1.52 ± 0.20-fold) while maintaining stable photothermal conversion under repeated NIR cycles. Mechanistic analysis reveals that interfacial TA–Cu complexes regulate charge delocalization and proton–electron transfer at the polymer–solution boundary, balancing redox catalysis with energy dissipation. This work establishes a sustainable platform for H₂O₂-driven redox and photo-thermal coupling, integrating conductive polymer chemistry with eco-friendly catalytic pathways. Full article

This study systematically investigates the catalytic degradation performance and reaction mechanism of Fe₈₀P₁₃C₇ Metal Glass (MG) in a Fenton-like system for the removal of Methylene Blue (MB). Kinetic experiments on degradation reveal that under acidic conditions (pH = 3), Fe₈₀P₁₃C₇ MG exhibits exceptional catalytic activity, achieving complete degradation of a 50 mg/L MB solution within 12 min. Its degradation rate significantly surpasses that of Fe₇₈Si₉B₁₃ MG and commercially available ZVI powder. Key parameters such as catalyst dosage, H₂O₂ concentration, solution pH, and initial dye concentration were systematically examined to determine the optimal reaction conditions. The characterization results indicate that Fe₈₀P₁₃C₇ MG maintains high activity even after multiple cycles of use, attributed to surface selective corrosion and crack formation during the reaction process. This “self-renewal” mechanism continuously exposes fresh active sites. Mechanistic studies confirm that the degradation process is driven by an efficient redox cycle between Fe²⁺/Fe³⁺ within the material, ensuring sustained and stable generation of •OH, which ultimately leads to the complete mineralization of MB molecules. This research provides solid experimental and theoretical foundations for the application of Fe₈₀P₁₃C₇ MG in dye wastewater treatment. Full article

The photo-Fenton process is an advanced oxidation method widely employed in environmental remediation. Herein, we developed a novel metal–organic framework@hydrogen-bonded organic framework (MOF/HOF) composite with excellent photo-Fenton-like activity for the efficient degradation of organic dye methylene blue (MB). Cu-based MOF (CuBTC) was firstly prepared via the solvothermal method, then melamine (MA) and trimesic acid (TMA)-based HOF (MA-TMA) was grown in situ on CuBTC with hydrogen bonding interactions to produce the MOF/HOF composite CuBTC-MA. The CuBTC-MA composite could catalyze H₂O₂ to produce active substances for efficient MB degradation. The degradation rate constant of the CuBTC-MA composite was 4.4 times and 16.7 times higher than that of CuBTC and MA-TMA. The remarkably enhanced performance was attributed to the synergistic effect between the efficient separation of electron–holes supported by the type-II heterojunction structure of the CuBTC-MA composite and the Cu(I)/Cu(II) inter-conversion. The CuBTC-MA composite demonstrated exceptional repeatability and maintained a stable performance across a broad pH range. This study provided a novel paradigm for engineering heterogeneous MOF/HOF heterostructures, demonstrating significant potential in advancing photo-Fenton-like catalytic systems for the efficient environmental remediation of organic pollutants through synergistic charge separation and radical generation mechanisms. Full article

Water pollution caused by synthetic dyes is a major environmental concern due to their stability, toxicity, and resistance to conventional wastewater treatments. This study presents a sustainable approach for synthesizing zinc oxide (ZnO) nanoparticles using artichoke biomass (waste) as a green precursor and enhancing their visible light photocatalytic activity through phosphorus doping. ZnO nanoparticles were successfully synthesized via a simple green route and doped with 3–6% phosphorus using NH₄H₂PO₄. The structural, morphological, and optical properties of the resulting P-ZnO were characterized by XRD, SEM/EDX, TEM, FTIR, and UV-Vis spectroscopy. (6 wt%) Phosphorus doping effectively reduced the band gap from 3.06 eV to 2.95 eV, extended light absorption into the visible range, and improved electron–hole separation, resulting in enhanced photocatalytic performance. The P-ZnO nanoparticles were evaluated for methylene blue (MB) degradation under visible light in a photo-Fenton-like process, with H₂O₂ as an oxidant. The degradation efficiency reached 87.05% with 6% P-ZnO and further increased to 92.35% upon addition of H₂O₂. Durability and reusability tests demonstrated that the 6% P-ZnO catalyst maintained its activity and structural integrity over four consecutive cycles, indicating negligible loss of efficiency and excellent resistance to surface poisoning. The photocatalytic activity was strongly impacted by the quantity of catalyst, solution pH, and initial dye levels, with optimal performance at 0.3 g/L catalyst loading, pH 3, and lower MB concentrations. Full article

Phenol, an essential feedstock widely used in manufacturing and chemical industries, inevitably results in the discharge of phenol-laden wastewater. To enhance the phenol-degradation efficiency of Fe-based amorphous alloys, a novel atomic-scale fabrication approach for Fe-Cu galvanic couples is proposed, enabling the rapid and uniform formation of micro/nano Fe-Cu structures on the surface of Fe-based alloys with significant improvement in the catalytic activity towards phenol. Micron/nano Fe-Cu couples can be fabricated within 15 s at 45 °C. Phenol degradation experiments reveal that the pristine amorphous alloy exhibits a 40 min hatching period before the phenol removal process, and it exhibits a kinetic constant (k_obs) of 0.1596 min⁻¹ after the hatching period, under conditions of 50 °C, 0.5 g/L catalytic loading, 10 mmol/L H₂O₂, and pH = 3 towards a 50 mg/L phenol solution. With the micro/nano Fe-Cu galvanic couples, the k_obs value markedly increased to 2.23~2.36 min⁻¹ under identical conditions except for 3 mmol/L H₂O₂, corresponding to approximately a 14-fold improvement. This cost-effective and time-efficient atomic-scale fabrication strategy offers a promising platform for the development of next-generation catalytic alloys and functional materials. Full article

This paper focuses on the research progress of iron-based plant-derived biochar in the field of Fenton-like organic wastewater treatment. Given the severe organic pollution problems in water bodies, advanced oxidation technologies have garnered significant attention. In Fenton-like reactions, iron-based catalysts play a crucial role but have limitations, while the characteristics of biochar make it an ideal carrier. This paper provides a detailed account of the preparation methods for iron-based plant-derived biochar, including one-step pyrolysis and co-precipitation methods, each with its own advantages and disadvantages. It introduces the application of iron-based plant-derived biochar in Fenton-like reactions, including single-metal, multi-metal, and composite material forms, and explains the activation mechanisms involving radical and non-radical pathways. Finally, it summarizes the advantages of this material and points out the need for further research in areas such as cost assessment, metal leaching, practical water body application, and intermediate product toxicity assessment, providing comprehensive references and directional guidance for future studies. Full article

The heterogeneous Fenton-like catalysts TiO₂/Fe₃O₄ were fabricated using maize straw as template (MST-TiO₂/Fe₃O₄) by calcination followed by the hydrothermal method. The characterization showed that higher Fe₃O₄ particle dispersion, closer interaction between TiO₂ and Fe₃O₄, stronger electron transfer ability, and lower leaching of Fe ions of MST-TiO₂/Fe₃O₄ catalyst resulted in higher catalytic activity towards the degradation of tetracycline (TC) compared to pure Fe₃O₄. The best conditions for TC degradation were initial pH = 6.74, 11.52 mmol/L of H₂O₂, 0.38 g/L of MST-TiO₂/Fe₃O₄, and a reaction time of 56.63 min according to the response surface methodology (RSM) result based on the Box–Behnken design (BBD). The quadratic model was well-fitted to the experimental data with R2 (0.9843) and adj-R2 (0.9660) by the analysis of variance (ANOVA). Under the optimum reaction conditions, a maximum removal rate of 98.67% was achieved. The findings of the present study revealed that heterogeneous UV–Fenton process catalyzed by MST-TiO₂/Fe₃O₄ was a suitable way for the degradation of TC from aqueous environment. Full article

Removing toxic formaldehyde (HCHO) from environmental water is crucial for human health and the ecosystem. Perovskite-type Lanthanum cobalt oxide (LaCoO₃) has achieved great success in a wide range of catalytic processes; however, this concept has been rarely applied to the degradation of HCHO. Here, we prepared perovskite-type catalysts with different La/Co molar ratios, and the time for HCHO oxidation degradation at room temperature was shortened by 12 times (10 min vs. 119 min) compared to other heterogeneous catalysts. LaCoO₃ exhibits superior catalytic activity for HCHO degradation at room temperature when the La/Co molar ratio is 1:1 compared to lanthanum cobalt oxides with other molar ratios. The X-ray photoelectron spectroscopy (XPS) test results show that increasing the La/Co molar ratio reduces the Co²⁺ content in the catalyst, while Co²⁺ plays the most important role in the catalyst. Quencher experiments indicated that sulfate radicals (SO₄·⁻) and hydroxyl radicals (·OH) were the primary reactive species for the removal of HCHO. This finding suggests that the catalytic oxidation reaction involving HCHO operates as a heterogeneous Fenton-like oxidation reaction. Full article

Growing concern over nanoplastics as emerging pollutants calls for effective treatment methods, with advanced oxidation processes (AOPs) showing strong potential for their degradation. This study examines the interaction between polyethylene terephthalate nanoplastics (PET-NPs) and magnetite nanoparticles (MNPs) in a heterogeneous Fenton-like system, focusing on colloidal behavior, hydroxyl radicals (^●OH) generation, and potential degradation pathways. Zeta potential (ZP) and particle diameter measurements were used to characterize nanoparticle dispersion and aggregation mechanisms over a pH range of 3–9.5. The results revealed a pronounced pH-dependent stability, with MNPs exhibiting larger hydrodynamic diameters (283 nm) and lower stability at pH 3 (ZP: −9.8 mV) compared with neutral or alkaline conditions (189 nm; ZP: −44 to −42 mV). PET-NPs exhibited minimal agglomeration at a pH of 9.5 (ZP: −25.6 mV). Unlike conventional Fenton systems, ^●OH production peaked at pH 7–9.5 (0.3–0.35 μM), attributed to preserved Fe²⁺ sites and reduced particle agglomeration. Although PET-NPs resisted oxidative degradation, their aggregation with MNPs enabled magnetic recovery (46% efficiency at pH 3) through charge screening, Fe³⁺/Fe²⁺ bridging, and hydrophobic interactions. These findings highlight MNPs’ potential for sustainable nanoplastic separation and emphasize the need for optimized catalysts to enhance ^●OH-driven degradation. Overall, this work advances understanding of nanoplastic–magnetite interactions and offers insights into AOP applications. Full article

Metallic glass, as an emerging catalytic material, possesses an atomic structure characterized by long-range disorder and short-range order, which creates abundant and accessible active sites that enhance the adsorption and reactivity toward pollutant molecules, particularly dye compounds. In treating highly colored and recalcitrant Reactive Black 5 (RB5) dye wastewater, Mo₅₁Fe₃₄B₁₅ metallic glass wire demonstrate outstanding catalytic degradation performance within a conventional Fenton-like system. Under acidic conditions (pH = 2), the material exhibits a degradation rate constant of 0.698 min⁻¹ for a 20 ppm RB5 dye solution, achieving a degradation efficiency of 98.8% within 10 min. After 10 consecutive cycles, the efficiency remains at 95%, and throughout 15 cycles, it consistently maintains a performance level above 90%. As the reaction proceeds, the degradation rate gradually decreases, primarily due to the accumulation of corrosion products on the catalyst surface, which are predominantly composed of MoO₃ and Fe₂O₃. During the degradation process, metallic Mo⁰ and Fe⁰ serve as electron donors that facilitate the decomposition of H₂O₂, generating highly reactive hydroxyl radicals (•OH). These radicals attack the chromophoric structure of the dye, leading to its structural disruption and enabling rapid decolorization. Full article

This study reports the development of polyvinylidene fluoride (PVDF) membranes decorated with a copper(II) complex (CuL) for the removal of organic pollutants from wastewater. Using Drimaren Red X-6BN (DRX-6BN) as a probe, the PVDF membrane with the lowest CuL loading (PVDF/PDA/CuL-4) reached an adsorption capacity of 19.78 mg/g at 300 min, with removal of up to 50% DRX-6BN. Kinetic analysis favored Elovich (R² > 0.9928; RMSE < 0.4489) and the pseudo-second-order model (R² > 0.9540; RMSE < 1.1388), consistent with chemisorption. Intraparticle diffusion occurred in two steps. In the presence of 20 mg/L of hydrogen peroxide (H₂O₂), the removal was >80% within 180 min at higher CuL loadings (PVDF/PDA/CuL-40). In oily wastewater, PVDF/PDA/CuL-4 achieved ~100% COD removal in 120 min with H₂O₂, whereas pristine PVDF achieved 38.5%. Storage stability tests demonstrated the preservation of catalytic and separation performance for at least three months. All tests were conducted at pH ≈ 6.0 and a temperature of 25 °C. In contrast to many catalytic membranes, these membranes operate at near-neutral pH and ambient temperature in the absence of radiation. The results highlight PVDF membranes decorated with CuL as a robust and sustainable approach for the treatment of oily effluents, particularly by combining Fenton-like processes under mild conditions. Full article

Phenolic compounds constitute the predominant group of recalcitrant organic contaminants in coal chemical wastewater. In this study, humic acid and urea were used as carbon and nitrogen sources to prepare nitrogen-doped carbon material (labeled as NC-800) through a two-step calcination process. Using this catalyst (NC-800) to activate PMS for phenol degradation achieved 100% phenol removal across a wide pH range (1–9). The removal rate remained at 99.62% even with high concentrations of inorganic anions or natural organic matter, breaking through the limitations of traditional Fenton-like reactions in terms of acid–base environment and anion influence. The quenching experiment and electron spin resonance (ESR) spectroscopy results indicated that the N-C/PMS system generated three active species hydroxyl radicals (•OH), superoxide radicals (O₂^•−), and singlet oxygen (¹O₂) through the active sites in electron-rich regions such as graphite nitrogen, pyrrole nitrogen, and C=O. An electrochemical test revealed that the system formed a metastable NC-800-PMS* complex during the reaction, indicating the existence of a non-radical pathway of electron transfer. The combination of free radicals (•OH, O₂^•−) and non-free radicals (¹O₂, electron transfer) facilitated the rapid degradation of phenol, providing a theoretical basis for phenol degradation. Full article

Introducing hierarchical structure into zeolites or synthesizing two-dimensional (2D) zeolite nanosheets have drawn much attention in catalysis and separation process due to the improvement in zeolites’ diffusion properties. In this study, Fe incorporated on the MFI zeolite framework (Fe-MFI) with the nanosheet morphology and unique hierarchical pore structure was successfully synthesized and applied for the adsorption and degradation of Rhodamine B (RhB) in a Fenton-like reaction in the presence of H₂O₂. The synthesis involved a seed-directed hydrothermal method in the presence of NH₄F and a subsequent NaOH treatment made the synthesized hierarchical Fe-MFI nanosheets (Fe-20-10) characterized by abundant highly dispersed framework Fe³⁺ species. As a result of these features, the Fe-20-10 showed excellent ability of adsorption and degradation efficiency of RhB, and enhanced durability due to negligible leaching of framework Fe³⁺ species. Moreover, the hydroxyl radicals were determined as the main the reactive oxygen species of RhB degradation, and a possible adsorption–degradation pathway was proposed. This work offers guidance for developing high-performance Fenton-like degradation catalysts. Full article

Due to its efficiency, advanced oxidation processes (AOP), such as photo-Fenton, have become an alternative for removing emerging contaminants like paracetamol. The objective of this work was to perform a life cycle assessment (LCA) according to ISO 14040/44 for a heterogeneous photo-Fenton process catalyzed by Cu/Fe-pillared clays (PILC) for the removal of paracetamol from water. The study covered catalyst synthesis and four treatment scenarios, with inventories built from experimental data and ecoinvent datasets; treatment time was 120 min per functional unit. Environmental impacts for catalyst synthesis were quantified with ReCiPe 2016 (midpoint), while toxicity-related impacts of the degradation stage were assessed with USEtox™ (human carcinogenic toxicity, human non-carcinogenic toxicity, and freshwater ecotoxicity). Catalyst synthesis dominated most midpoint categories, the global warming potential for 1 g of Cu/Fe-PILC was 10.98 kg CO₂ eq. Toxicity results for S4 (photo-Fenton Cu/Fe PILC) showed very low values: 9.73 × 10⁻¹² CTUh for human carcinogenic and 1.29 × 10⁻¹³ CTUh for human non-carcinogenic. Freshwater ecotoxicity ranged from 5.70 × 10⁻⁴ PAF·m³·day at pH 2.7 (≥60 min) to 1.67 × 10⁻⁴ PAF·m³·day at pH 5.8 (120 min). Overall, optimizing pH and reaction time, are key levers to improve the environmental profile of AOP employing Cu/Fe-PILC catalysts. Full article

In this study, the use of spent coffee waste as a green precursor of polyphenolic compounds, which are subsequently employed as reducing agents for the synthesis of zero-valent iron nanoparticles (nZVI) aimed at the efficient removal of dyes from aqueous systems, has been investigated. The nanoparticles, generated in situ in the presence of controlled amounts of hydrogen peroxide, were applied in the removal of organic dyes—including methylene blue, methyl orange, and orange G—through a heterogeneous Fenton-like catalytic process. The synthesized nZVI were thoroughly characterized by nitrogen adsorption at 77 K, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and powder X-ray diffraction (XRD). A statistical design of experiments and response surface methodology were employed to evaluate the effect of polyphenol, Fe(III), and H₂O₂ concentrations on dye removal efficiency. Results showed that under optimized conditions, a 100% removal efficiency could be achieved. This work highlights the potential of nZVI synthesized from agro-industrial waste through sustainable routes as an effective solution for water remediation, contributing to circular economy strategies and environmental protection. Full article