Iron nanoparticles surface decorated MXene via molten salts etching as selenium host for ultrafast sodium ion storage

Sodium-selenium (Na-Se) batteries have gained attention due to their high energy density and power density, resulting from the liquid-liquid reaction at the interface in the dimethoxyethane electrolyte. Nevertheless, the pronounced shuttle effect of polyselenides causes low coulomb efficiency and inadequate cycling stability for Na-Se batteries. Herein, the iron nanoparticles surface modified accordion-like Ti3C2Tx MXene (MXene/Fe) synthesized via the molten salt etching is utilized as the host of Se species for high-performance Na-Se battery cathode. Benefiting from the layered structure and chemical adsorption of accordion-like MXene, the shuttle effect of the cathode is effectively inhibited. Simultaneously, electrochemical kinetics is boosted due to the catalytic effect of Fe nanoparticles, which facilitate the transformation of polyselenide from long-chain to short-chain, contributing to pseudocapacitive capacity. Consequently, the Se-based cathode delivers a steady capacity of 575.0 mA h g-1 at 0.2 A/g, and even a high capacity of 500 mAh/g at 50 A/g based on the mass of Se@MXene/Fe electrode, indicating the ultrafast Na+ ion storage. Most notably, this structure demonstrated remarkable long-term cycling stability for 5000 cycles with a high capacity retention of 97.4 %. The electrochemical energy storage mechanism is further revealed by in situ Raman. Herein, the confinement-catalysis structure shines light on inhibiting shuttling and facilitating ultrafast ion storage.

Insight into the effect of catalytic reactions on correlations of soot oxidation activity and microspatial structures

A catalyst is usually coated on Diesel particulate filter (DPF) for assisted regeneration. In this paper, the oxidation activity and pore structure evolutions of soot under the effect of CeO₂ are explored. CeO₂ effectively increases the oxidation activity of soot and reduces the initial activation energy; in the meantime, the addition of CeO₂ changes the soot oxidation mode. Pure soot particles tend to produce the porous structure in the oxidation process. Mesopores promote the diffusion of oxygen, and macropores contribute to reduce the agglomeration of soot particles. Additionally, CeO₂ provides the active oxygen for soot oxidation and promotes the multi-point oxidation at the beginning of soot oxidation. With the oxidation proceeding, catalysis causes the collapsion of soot microspatial structures, in the meantime, the macropores caused by the catalytic oxidation are filled by CeO₂. It results in the tight contact between soot and catalyst, further promoting the formation of the available active oxygen for soot oxidation. This paper is meaningful to analyze the oxidation mechanism of soot under catalysis, which lays a foundation for improving the regeneration efficiency of DPF and reducing the particle emission.

Removal of iodide anions in water by silver nanoparticles supported on polystyrene anion exchanger

The removal of iodide (I^-) from source waters is an effective strategy to minimize the formation of iodinated disinfection by-products (DBPs), which are more toxic than their brominated and chlorinated analogues. In this work, a nanocomposite Ag-D201 was synthesized by multiple in situ reduction of Ag-complex in D201 polymer matrix, to achieve highly efficient removal of iodide from water. Scanning electron microscope /energy dispersive spectrometer characterization showed that uniform cubic silver nanoparticles (AgNPs) evenly dispersed in the D201 pores. The equilibrium isotherms data for iodide adsorption onto Ag-D201 was well fitted with Langmuir isotherm with the adsorption capacity of 533 mg/g at neutral pH. The adsorption capacity of Ag-D201 increased with the decrease of pH in acidic aqueous solution, and reached the maximum value of 802 mg/g at pH 2. This was attributed to the oxidization of I^-, by dissolved oxygen under the catalysis of AgNPs, to I₂ which was finally adsorbed as AgI₃. However, the aqueous solutions at pH 7 - 11 could hardly affect the iodide adsorption. The adsorption of I^- was barely affected by real water matrixes such as competitive anions (SO₄^2-, NO₃^-, HCO₃^-, Cl^-) and natural organic matter, of which interference of NOM was offset by the presence of Ca²⁺. The proposed synergistic mechanism for the excellent performance of iodide adsorption by the absorbent was ascribed to the Donnan membrane effect caused by the D201 resin, the chemisorption of I^- by AgNPs, and the catalytic effect of AgNPs.

Biomass-assisted fabrication of rGO-AuNPs as surface-enhanced Raman scattering substrates for in-situ monitoring methylene blue degradation

Reduced graphene oxide-gold nanoparticles nanocomposites (rGO-AuNPs) with high surface-enhanced Raman scattering (SERS) activity was created by biomass-assisted green synthesis with Lilium casa blanca petals biomass for the first time, and its application for methylene blue (MB) degradation was explored through in-situ monitoring. Lilium casa blanca petals biomass was used as a reducing agent to reduce GO and chloroauric acid successively when carrying out rGO-AuNPs in-situ synthesis while it also acted as a capping agent. The produced rGO had oxygen-containing functional groups which had an outstanding performance in enhancing the SERS effect. Characterization results confirmed that the AuNPs were grafted onto the rGO sheet, and the mechanism study showed that total flavonoids in Lilium casa blanca petals biomass were the main biological compounds involved in the reduction. rGO-AuNPs had a high Raman enhancement factor (EF) which could reach 3.88 × 10⁷. The synthesized nanocomposite also had a good catalytic activity that could be employed as catalyst in MB degradation, and it could complete degradation within 15min. The reaction rate increased linearly with the amount of rGO-AuNPs, and the degradation could be in-situ monitored both by UV and SERS.

Self-circulation of oily spent hydrodesulphurization (HDS) catalyst by catalytic pyrolysis for high quality oil recovery

In this study, roasted spent HDS ash (sHDSc-A) was used for the first time to catalytically pyrolyze oily spent HDS catalysts (sHDSc) to improve the yield and quality of pyrolysis oil. The results showed that sHDSc-A promoted the decomposition of coke in oily sHDSc, resulting in the recovery of more oil and gas. Meanwhile, sHDSc-A significantly improved the quality of the pyrolysis oil. They inhibited the aromatization of alkanes to increase the saturation of the pyrolysis oil from 59.39% to 74.25% and the H/C radio from 1.62 to 1.72; promoted the decomposition of long-chain alkanes to increase the content of C11-C22 from 41.97% to 61.99%; enhanced the conversion of carboxylic acids to ketones led to the reduction of heteroatomic compounds such as N (56.10%-45.39%), S (66.95%-56.59%), and O (45.26%-26.70%) in the pyrolysis oil. The promotion of sHDSc-A in the pyrolysis process is attributed to the catalytic effect of the metal oxides in sHDSc-A. Among them, Al₂O₃ and Fe₂O₃ can promote decarboxylation of carboxylic acids and reduce O mobility, while MoO₃ and Fe₂O₃ play a significant role in reducing coke and increasing pyrolysis oil. NiO can also promote methane vapor reforming, and thus increase the production of H₂ in non-condensable gas. This study achieves self-circulation of oily sHDSc with a "waste-treatment-waste" strategy that presents the advantage of value-added energy recovery and waste reuse.

A rational design of titanium-based heterostructures as electrocatalyst for boosted conversion kinetics of polysulfides in Li-S batteries

Lithium-sulfur batteries have great potential for next-generation electrochemical storage systems owing to their high theoretical specific energy and cost-effectiveness. However, the shuttle effect of soluble polysulfides and sluggish multi-electron sulfur redox reactions has severely impeded the implementation of lithium-sulfur batteries. Herein, we prepared a new type of Ti₃C₂-TiO₂ heterostructure sandwich nanosheet confined within polydopamine derived N-doped porous carbon. The highly polar heterostructures sandwich nanosheet with a high specific surface area can strongly absorb polysulfides, restraining their outward diffusion into the electrolyte. Abundant boundary defects constructed by new types of heterostructures reduce the overpotential of nucleation and improve the nucleation/conversion redox kinetics of Li₂S. The Ti₃C₂-TiO₂@NC/S cathode exhibited discharge capacities of 1363, and 801 mAh g^-1 at the first and 100th cycles at 0.5C, respectively, and retained an ultralow capacity fade rate of 0.076% per cycle over 500cycles at 1.0C. This study provides a potential avenue for constructing heterostructure materials for electrochemical energy storage and catalysis.

Transition metal elements-doped SnO2 for ultrasensitive and rapid ppb-level formaldehyde sensing

Pristine SnO₂, Fe-doped SnO₂ and Ni-doped SnO₂ were synthesized using facile hydrothermal method. Analysis based on XRD, TEM and UV-Vis DRS measurements demonstrated the successful insertion of Fe and Ni dopants into SnO₂ crystal. Formaldehyde-detection measurements revealed that transition metal-doped SnO₂ exhibited improved formaldehyde-sensing properties compared with that of pristine SnO₂. When the amount of incorporated dopant (Fe or Ni) was 4 at.%, the most effective enhancement on sensing performance of SnO₂ was obtained. At 160 °C, the 4 at.% Fe-SnO₂ and 4 at.% Ni-SnO₂ exhibited higher response values of 7.52 and 4.37 with exposure to low-concentration formaldehyde, respectively, which were 2.4 and 1.4 times higher than that of pristine SnO₂. The change of electronic structure and crystal structure as well as catalytic effect of transition metals are chiefly responsible for the enhanced sensing properties.

Catalytic effect of diesel PM derived ash on PM oxidation activity

With diesel particulate filter and gasoline particulate filter periodical regeneration, more and more ash accumulates on the substrate of filter. Ash gathering on the substrate of filter leads to more contact area of particulate matter and ash. Specific ingredients in ash present catalytic effects on particulate matter oxidation. However, the catalytic effect of diesel particulate matter derived ash on its oxidation, mimicking the ash accumulating on filter substrate, is still uncovered using experiments. In this paper, diesel particulate matter derived ash was put at the bottom of particulate matter samples to imitating the soot loading on filter substrate which was covered by much ash. The results indicated that the burnout temperature of diesel particulate matter was in the range of 500-600 °C; while it was 600-700 °C for Printex (U). The burnout temperature drop by ash was lower than 10 °C for diesel particulate matter. The maximum mass loss rate corresponded to approximately 450 °C for diesel particulate matter, and it was changed minorly by ash and ramp rates. However, the temperature corresponding to the maximum mass loss rate was seriously retarded by high ramp rates for Printex (U), and ash presented limited effect on it. The maximum activation energy drop by ash was approximately 60 kJ/mol at the initial stage of oxidation for diesel particulate matter. The activation energy was approximately 132.19, 114.78, 157.26, and 144.67 kJ/mol for diesel PM, diesel PM-ash, Printex (U), and Printex (U)-ash, respectively. Organic compounds dropped gradually in the oxidation process of diesel particulate matter. Nanostructure evolutions of diesel particulate matter and Printex (U) were similar, experiencing smaller sizes and void cores at the end of oxidation process.

Co-pyrolysis of microalgae and other biomass wastes for the production of high-quality bio-oil: Progress and prospective

Microalgae are the most prospective raw materials for the production of biofuels, pyrolysis is an effective method to convert biomass into bioenergy. However, biofuels derived from the pyrolysis of microalgae exhibit poor fuel properties due to high content of moisture and protein. Co-pyrolysis is a simple and efficient method to produce high-quality bio-oil from two or more materials. Tires, plastics, and bamboo waste are the optimal co-feedstocks based on the improvement of yield and quality of bio-oil. Moreover, adding catalysts, especially CaO and Cu/HZSM-5, can enhance the quality of bio-oil by increasing aromatics content and decreasing oxygenated and nitrogenous compounds. Consequently, this paper provides a critical review of the production of bio-oil from co-pyrolysis of microalgae with other biomass wastes. Meanwhile, the underlying mechanism of synergistic effects and the catalytic effect on co-pyrolysis are discussed. Finally, the economic viability and prospects of microalgae co-pyrolysis are summarized.

Microwave-assisted catalytic hydrothermal carbonization of Laminaria japonica for hydrochars catalyzed and activated by potassium compounds

There are limited investigations describing preparation and application of alga-based hydrochars via microwave-assisted catalytic hydrothermal carbonization (MA-CHTC). Therefore, hydrochars were successfully prepared from macroalgae biomass Laminaria japonica impregnated with KH2PO4, KCl, K2CO3, and KOH as acidic, neutral salt, and alkaline catalysts, respectively, via the MA-CHTC. Comprehensive characterization of physicochemical properties of the hydrochars, including yields, elemental and phase composition, specific surface areas, functional groups, and morphology, confirmed different catalytic effects of these catalysts on hydrochar formation. Adsorption kinetics and isotherms of Pb(II) revealed significant improvement of adsorption capacities for Pb(II) due to synergetic chemical activation of the spiked catalysts. Therefore, the synergetic catalytic effects and chemical activation is benefic for tailored design of engineered hydrochars with different properties for special application through selection of catalysts during the MA-CHTC process.

Detection of silver through amplified quenching of fluorescence from polyvinyl pyrrolidone-stabilized copper nanoclusters

Silver ion detection with ultra-high sensitivity was established. We synthesized copper nanoclusters (CuNCs) with blue fluorescence through a one-pot process. Instead of a direct quencher toward the CuNCs, silver ions activated the strong oxidation from persulfate and subsequently converted divalent manganese ion into manganese dioxide (MnO₂). The surface charges of MnO₂ and the CuNCs brought them together and quenched the fluorescence from the latter. Due to silver ions' role as the catalyst in the process, it cycled and even a small amount leads to a significant fluorescence change. This signaling provided the determination of  silver ions in the range 5 pM~1 nM, with a detection limit of  1.2 pM. The method is selective, and its applicability was validated through practical water sample analyses.

Mitigation of bromine-containing products during pyrolysis of polycarbonate-based tetrabromobisphenol A in the presence of copper(I) oxide

Polycarbonate (PC) is an engineering thermoplastic that is widely used in electrical and electronic equipment. This plastic often contains tetrabromobisphenol A (TBBA), the most common brominated flame retardant. Thermal degradation of the PC-TBBA leads to generation of numerous bromo-organic products in the pyrolytic oil, hindering its appropriate utilization, as well as corrosive hydrogen bromide gas. The purpose of this study was to experimentally investigate and compare the pyrolysis products of PC-TBBA and PC-TBBA + Cu₂O at various temperatures, with an emphasis on the yield and distribution of brominated compounds. In pyrolysis of PC-TBBA + Cu₂O, at the maximum degradation temperature (600 °C), as much as 86% of total Br was trapped in the residue, while 3% and 11% were distributed in the condensate and gas fractions, respectively. In contrast, the distribution of Br from non-catalytic pyrolysis of PC-TBBA (600 °C) was 0.5% residue, 40% condensate, and 60% gas. The results of this study revealed that in the presence of Cu₂O, organo-bromine products were most likely involved in Ullman-type coupling reactions, leading to early cross-linking of the polymer network that efficiently hinders their vaporization. HBr in the gas fraction was suppressed due to effective fixation of bromine in residue in the form of CuBr.

A chemiluminescence assay for determination of lysozyme based on the use of magnetic alginate-aptamer composition and hemin@HKUST-1

Lysozyme aptamer-functionalized magnetic alginate hydrogel was prepared for separation and enrichment of lysozyme. Luminol-labeled aptamer was used as a signal tag, and the signal tag was adsorbed on magnetic carboxylated carbon nanotubes based on the π-interaction. When lysozyme was added, the aptamer specifically binds to the lysozyme, causing the signal tag to detach from the magnetic carboxylated carbon nanotubes. When the aptamer/lysozyme complex bound to the complementary single strand of aptamer on the hemin@HKUST-1, lysozyme was released. The released lysozyme can be recombined with the signal tag adsorbed on the magnetic carboxylated carbon nanotube, allowing more signal tag to be dispersed into the solution. Determination of lysozyme was achieved by releasing the luminol-labeled aptamer to generate a chemiluminescence signal at a wavelength of 425 nm. It was proved by experiments that the synthesized hemin@HKUST-1 had a strong catalytic effect on the luminol-NaOH-H₂O₂ system. The chemiluminescence signal was increased nearly 100 times. The complementary pairing allowed the luminol to be immobilized on the surface of hemin@HKUST-1. The generation and consumption of short-lived reactive oxygen species were concentrated on the surface of the MOFs, which improves the chemiluminescence efficiency. The introduction of hemin@HKUST-1 and DNA solved the defects of chemiluminescence analysis. The chemiluminescence assay was able to detect lysozyme with linear range of 1.05 × 10^-6 U∙mg^-1 (6.00 × 10^-13 mol∙L^-1)-1.25 × 10^-2 U∙mg^-1 (7.14 × 10^-9 mol∙L^-1); the detection limit was 3.50 × 10^-7 U∙mg^-1 (2.00 × 10^-13 mol∙L^-1) (R² = 0.99). The recovery of lysozyme in spiked saliva samples was 97.4-102.8%. Graphical abstract Schematic presentation of chemiluminescence assay. Lysozyme (Lys) was captured by aptamer-modified magnetic sodium alginate (M-Alg-Apt); Glycine (pH = 2) as eluent for Lys. Luminol-modified Apt (Apt-luminol) as signal tag; magnetic carbon nanotubes (MCNTs) as adsorption matrix; cDNA was complementary to Apt; hemin@HKUST-1 as catalyst.

Light enhanced room temperature resistive NO2 sensor based on a gold-loaded organic-inorganic hybrid perovskite incorporating tin dioxide

A material is described for sensing NO₂ in the gas phase. It has an architecture of type Au/MASnI₃/SnO₂ (where MA stands for methylammonium cation) and was fabricated by first synthesizing Au/MASnI₃ and then crystallizing SnO₂ on the surface by calcination. The physical and NO₂ sensing properties of the composite were examined at room temperature without and with UV (365 nm) illumination, and the NO₂-sensing mechanism was studied. The characterization demonstrated the formation of a p-n heterojunction structure between p-MASnI₃ and n-SnO₂. The sensor, best operated at a voltage of 1.1 V at room temperature, displays superior NO₂ sensing performance. Figures of merit include (a) high response (R_g/R_a = 240 for 5 ppm NO₂; where R_g stands for the resistance of a sensor in test gas, and R_a stands for the resistance of a sensor in air), (b) fast recovery (about 12 s), (c) excellent selectivity compared to sensors based on the use of SnO₂ or Au/SnO₂ only, both at room temperature under UV illumination; (d) a low detection limit (55 ppb), and (e) a linear response between 0.5 and 10 ppm of NO₂. The enhanced sensing performance is mainly attributed to the high light absorption capacity of MASnI₃, the easy generation and transfer of photo-induced electrons from MASnI₃ to the conduction band of SnO₂, and the catalytic effect of gold nanoparticles. Graphical abstract Schematic of the energy band diagrams of the gold-functionalized MASnI₃/SnO₂ system after equilibrium with UV illumination, by which the enhanced sensing performance for NO₂ can be explained.

Design rules of heteroatom-doped graphene to achieve high performance lithium-sulfur batteries: Both strong anchoring and catalysing based on first principles calculation

A number of observations have been reported on chemical capture and catalysis of anchoring materials for lithium-sulfur batteries. Here, we propose the design principles for the chemical functioned graphene as an anchor material to realize both strong chemical trapping and catalysis. Through the first principle, the periodic law is calculated from the theory. Seven different co-doping series were investigated, e.g. MN₄@graphene (M = V, Cr, Mn, Fe, Co, Ni, and Cu). From binding energy, partial density of state, and charge density difference analysis, the FeN₄ and CrN₄ co-doped graphene show good performance for the lithium-sulfur battery from both strong anchoring and catalytic effects. For the most kinds of Li₂S_x (x = 1, 2, 4, 6, 8) absorption, two combinations can be achieved, including S-bonding and Li-bonding. The competition between the MS and the NLi shows the main difference of the co-doped configurations. Moreover, the S-bonding systems have better performance for both moderate chemical trapping and strong catalysis. The binding energies of Li₂S_x and Li decomposed properties considered as the key descriptors for the rational design of lithium-sulfur battery. Lastly, we offer design rules for high performance lithium-sulfur batteries based on the chemical functional graphene materials.

Iron and copper catalysis of PCDD/F formation

The formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) was explored during de novo tests designed to compare the catalytic activity of copper (II) chloride (CuCl2) with that of iron (III) oxide (Fe2O3) and to test some synergistic effect between these two catalytic compounds. Both copper chloride (CuCl2) and iron oxide (Fe2O3) were earlier proposed as catalysts to explain the PCDD/F emissions from, e.g. municipal solid waste incineration (MSWI). In addition, haematite (Fe2O3) is the main iron ore and could be responsible for the typical iron ore sintering plant fingerprint. A total of nine model fly ash (MFA) samples were prepared by mixing and grinding of sodium chloride (NaCl), activated carbon and a powder matrix of silica (SiO2) with the selected metal compound(s). The conditions of these de novo tests were 1 h in duration, 350 °C in a flow of synthetic combustion gas (10 vol.% oxygen in nitrogen). The effect of Fe-Cu catalyst concentration on yield and distribution pattern of PCDD/F was systematically explored; three strongly differing ratios of [Fe]:[Cu] were considered (1:1, 10:1 and 100:1) to study the potential interactions of Fe2O3 and CuCl2 suggested earlier. The results show some slight rise of PCDD/F formed with raising iron concentration from 0 to 10.1 wt% (no Cu added; 0.1 wt% Cu), as well as strong surging of both amount and average chlorination level of PCDD/F when rising amounts of copper (0 to 1.1 wt%) are introduced. The resulting fingerprints are compared with those from sintering and from MSWI.

Effects of metal ions on disinfection byproduct formation during chlorination of natural organic matter and surrogates

The effects of calcium, cupric, ferrous and ferric ions on the formation of trihalomethanes (THMs) and haloacetic acids (HAAs) were investigated using natural organic matter (NOM), small molecular weight NOM surrogates and natural water samples. The results showed that the effects were greatly dependent on the disinfection byproduct (DBP) precursor structure and molecular weight, and metal ions species. While using NOM as precursors, addition of 4.00 mM calcium ions increased the formation of THMs, dihaloacetic acids (DHAAs) and trihaloacetic acids (THAAs) by 24-47%, 51-61% and 15-25%, respectively. Addition of cupric ions at 0.02 mM increased the formation of THMs and DHAAs by 74-83% and 90-100%, respectively, but decreased the formation of THAAs by 26-27%. Similar effect was not observed when 0.04 mM ferrous or ferric ions were added. The effects of calcium and cupric ions on DBP formation were generally more evident for the NOM surrogates than that for NOM. The primary catalytic effect of calcium ions was due to complexation and less sensitive to molecular structure or weight, while that of cupric ions was attributed to redox reactions and greatly dependent on molecular structure. Both ferric and ferrous iron had substantial effects on the DBP formation of surrogates (citric acid and catechol in particular), which implied that the catalytic effects of ferric and ferrous iron mainly depended on molecular weight. The catalytic effect of cupric ions was also observed on natural water samples, while the effects of calcium, ferrous and ferric ions on natural water samples were not evident.

Experimental and molecular modeling studies of the interaction of the polypyridyl Fe(II) and Fe(III) complexes with DNA and BSA

Two mononuclear iron complexes, [Fe(tppz)₂](PF₆)₂·H₂O (1) and Fe(tppz)Cl₃·2CHCl₃ (2) where tppz is (2,3,5,6-tetra(2-pyridyl)pyrazine), have been synthesized and characterized by elemental analysis, spectroscopic methods (UV-Vis and IR) and single crystal X-ray structure analysis. The interaction of (1) as the nitrate salt ([Fe(tppz)₂](NO₃)₂) with calf-thymus DNA (CT-DNA) has been monitored by UV-Vis spectroscopy, competitive fluorescence titration, circular dichroism (CD), voltammetric techniques, viscosity measurement, and gel electrophoresis. Gel electrophoresis of DNA with [Fe(tppz)₂](NO₃)₂ demonstrated that the complex also has the ability to cleave supercoiled plasmid DNA. The results have indicated that the complex binds to CT-DNA by three binding modes, viz., electrostatic, groove and partial insertion of the pyridyl rings between the base stacks of double-stranded DNA. Molecular docking of [Fe(tppz)₂](NO₃)₂ with the DNA sequence d(ACCGACGTCGGT)₂ suggests the complex fits into the major groove. The water-insoluble complex (2) can catalyze the cleavage of BSA at 40 °C. There are no reports of the catalytic effect of polypyridyl metal complexes on the BSA cleavage. Molecular docking of (2) with BSA suggests that, when the chloro ligands in the axial positions are replaced by water molecules, the BSA can interact with the Fe(III) complex more easily.

Catalytic effect of transition metals on microwave-induced degradation of atrazine in mineral micropores

With their high catalytic activity for redox reactions, transition metal ions (Cu(2+) and Fe(3+)) were exchanged into the micropores of dealuminated Y zeolites to prepare effective microporous mineral sorbents for sorption and microwave-induced degradation of atrazine. Due to its ability to complex with atrazine, loading of copper greatly increased the sorption of atrazine. Atrazine sorption on iron-exchanged zeolites was also significantly enhanced, which was attributed to the hydrolysis of Fe(3+) polycations in mineral micropores and electrostatic interactions of protonated atrazine molecules with the negatively charged pore wall surface. Copper and iron species in the micropores also significantly accelerated degradation of the sorbed atrazine (and its degradation intermediates) under microwave irradiation. The catalytic effect was attributed to the easy reducibility and high oxidation activity of Cu(2+) and Fe(3+) species stabilized in the micropores of the zeolites. It was postulated that the surface species of transition metals (monomeric Cu(2+), Cu(2+)-O-Cu(2+) complexes, FeO(+), and dinuclear Fe-O-Fe-like species) in the mineral micropores were thermally activated under microwave irradiation, and subsequently formed highly reactive sites catalyzing oxidative degradation of atrazine. The transition metal-exchanged zeolites, particularly the iron-exchanged ones, were relatively stable when leached under acidic conditions, which suggests that they are reusable in sorption and microwave-induced degradation. These findings offer valuable insights on designing of effective mineral sorbents that can selectively uptake atrazine from aqueous solutions and catalyze its degradation under microwave irradiation.