M-Sn-Q (M = Zn, Cd; Q = S, Se) Compounds Templated by (Alkyl)ammonium Species: Synthesis, Crystal Structure, and Sr2+ Adsorption Property.

Deep investigations on the synthetic and structural chemistry of heterometallic chalcogenidostannates bear fundamental significance for the establishment of the structure-property relationship that would offer guidance on the functional material innovation. Presented here are four ammonium- and/or alkylammonium-directed M-Sn-Q (M = Zn, Cd; Q = S, Se) compounds, namely, [NH4]7[H3O]3Zn4Sn4S17 (1), [NH4]5[(CH3)2NH2]Zn4Sn5S17 (2), [CH3CH2NH3]22Zn16Sn12Se51(H2O)4·16H2O (3), and [NH4]2CdSnSe4 (4). All four compounds were synthesized in deep eutectic solvents (DESs) or ethylamine aqueous solution, both of which function simultaneously as reaction media and structure-directing agents. Compound 1 consists of discrete P1-[Zn4Sn4S17]10- clusters templated by mixed [NH4]+/[H3O]+ cations. In compound 2, such P1 clusters are bridged by Sn4+ ions in a 4,4-connection mode to form a [Zn4Sn5S17]n6n- framework with three types of cavities (I-III) varying in size. The two smaller cavities (I and II) accommodate NH4+ while the larger one(III) is occupied by [(CH3)2NH2]+, reflecting the rational size-dependence of cations on cavities. Compound 3 features an [Zn16Sn12Se51(H2O)4]n22n- open framework constructed from the 4,3-connection of P1-[Zn4Sn4Se17]10- clusters and {Zn(H2O)}2+ bridges. This linkage mode contributes to a large cage-like subunit (inner dimension: 21.99 × 9.06 Å2) and therefore an ultrahigh porosity that are occupied by [CH3CH2NH3]+ cations and water molecules (volume fraction: 57.7%). Compound 4 exists as a stacking of [CdSnSe4]n2n- chains, which are composed of alternatively arranged {CdSe4} and {SnSe4} tetrahedra, in combination with [NH4]+ cations as both charge-compensating and space-filling agents. Detailed synthetic, structural, and topological analyses were performed on these solid materials, coupled with extensive investigations on their optical and thermal properties. Compound 3 exhibits an efficient Sr2+ adsorption performance, featuring ultrafast kinetics (94.69% in 5 min), high removal rate (98.57% in 20 min) at equilibrium, and high capacity (104.17 ± 23.53 mg g-1).

Tailoring Hybrid Aluminoborate Frameworks by Incorporating Multicomponent Cadmium-Amine Complexes with Various Conformations.

Inorganic-organic hybrid aluminoborates represent a subclass of porous materials, which rely on effective construction method and structure-directing agents. Herein, we prepared a series of hybrid aluminoborates through covalent decoration of unsaturated Cd2+ complexes, whose formation take advantage of chelating amine and long-chain diamine as mixed ligands. These isolated compounds, that is, [Cd(en)(1,4-dab)0.5][AlB5O10] (1a; its analogue with discrete complex [Cd(en)(dien)H2O][AlB5O10] is denoted as 1b), [Cd(1,2-dap)1.5(1,4-dabH)0.5]{Al[B5O8(OH)2](B5O10)0.5} (2), and [Cd(en)(1,3-dap)][AlB5O10] (3) feature open frameworks (1a, 1b, and 3) or a sandwich-like porous layer (2) that are constructed by AlO4 tetrahedra and [B5O10]5-/[B5O8(OH)2]3- clusters. However, they exhibit different structural features in interconnection, channel environment, and topology as a result of diversified interactions between unsaturated complexes and aluminoborate frameworks, that is, through forming two Cd-O bonds with (i) a pair of neighboring BO3 and AlO4, (ii) the same AlO4, or (iii) the same BO3. The variation in connection mode exerts essential influence on binding effects and steric hindrance that are reflected by changes in interatomic distance, bond angle, window configuration, and interlinkage of units. In addition, the incorporation of unsaturated Cd2+ complexes endows these aluminoborate materials with photoluminescence function. Compound 3 with a noncentrosymmetric structure exhibits second harmonic generation (SHG) response approximately 0.7 times that of KDP. The preparation strategy for hybrid aluminoborates proposed here combines well molecular design with templating assembly, whose synergistic effect would be crucial for drawing a rational pathway for inorganic synthesis, especially with focus on structural and functional innovation.

Mixed Solvothermal Synthesis of Tn Cluster-Based Indium and Gallium Sulfides Using Versatile Ammonia or Amine Structure-Directing Agents.

Metal chalcogenide supertetrahedral Tn clusters are of current interest for their unique compositions and structures, which rely highly on the structure-directing agents. Herein, we report four novel Tn cluster-based indium and gallium sulfides, namely, [NH(CH3)3]4In4S10H4 (1), (NH3)4Ga4S6 (2), [NH3CH2CH3]5(NH2CH2CH3)2Ga11S19 (3), and [NH3CH2CH2OH]6Ga10S18·2NH2CH2CH2OH (4). All four compounds were solvothermally synthesized in mixed amine-ethanol solutions or deep eutectic solvent (DES), where ammonia/amine molecules play significant structure-directing roles in the speciation and crystal growth. (1) Being protonated, the trimethylamine and ethanolamine molecules surround the T2-[In4S10H4]4- clusters (for 1) and [Ga10S18]n6n- open framework (for 4), respectively, compensating for the negative charge of the inorganic moieties. (2) With the lone pair of electrons, the ammonia molecules in 2 coordinate directly to corner Ga3+ ions of the {Ga4S6} cage to give a neutral T2-(NH3)4Ga4S6 cluster. (3) For compound 3, part of the ethylamine molecules act as terminating ligands for the T1 and T3 units in the [Ga11S19(NH2CH2CH3)2]n5n- layer, while the rest act as interlamellar countercations upon protonation. Theoretical studies reveal the contributions of N, C, and H to the density of states (DOS) for 2 and 3 because of their hybrid structures that combine the ammonia/amine ligands with sulfide moieties together.

Efficient Cs+-Sr2+ Separation over a Microporous Silver Selenidostannate Synthesized in Deep Eutectic Solvent.

Efficient Cs+-Sr2+ separation, highly desirable for radionuclide recovery in medical and industrial applications, was achieved by the ion exchange technique over a novel microporous silver selenidostannate, [NH3CH3]0.5[NH2(CH3)2]0.25Ag1.25SnSe3 (AgSnSe-1). This material was synthesized in deep eutectic solvent (DES), where the alkylammonium cations play significant structure-directing roles in the construction of micropores that allow for selective ion exchange toward Cs+ against Sr2+. The much greater KdCs (1.06 × 104 mL g-1) over KdSr (87.7 mL g-1) contributes to an outstanding separation factor SFCs/Sr of ∼121.4 that is top-ranked among inorganic materials. An ion exchange column filled with AgSnSe-1 exhibits a remarkable separation effect for 10 000 bed volumes of continuous flow, with removal rates of ∼99.9% and ∼0 ± 5.5% for Cs+ and Sr2+, respectively. AgSnSe-1 exhibits excellent ß and γ radiation resistances and a chemical stability over a broad pH range of 1-12. The Se leaching level below the safe guideline value for drinking water highlights the environmental-friendly nature of AgSnSe-1. The high Cs+ exchange performance is almost unaffected by Na+, Mg2+, and Ca2+ cations. The Cs+-laden product AgSnSe-1Cs can be facilely eluted for recycling use, highlighting the great potential of open framework metal selenides in nuclear waste treatment and renewable energy utilization.

Removal of Sr2+ Ions by a High-Capacity Indium Sulfide Exchanger Containing Permeable Layers with Large Pores.

An ethylammonium-templated indium sulfide, [CH3CH2NH3]6In8S15 (InS-2), featuring anionic layers perforated with large, 24-membered rings that facilitate the accommodation of hydrated Sr2+ ions is reported. InS-2 exhibits an excellent adsorption performance toward Sr2+ with a top-ranked capacity (qm = 143.29 mg g-1), rapid kinetics, wide pH durability (3-14), ß- and γ-radiation resistances, and a facile elution.

Effective and Rapid Adsorption of Sr2+ Ions by a Hydrated Pentasodium Cluster Templated Zinc Thiostannate.

Separation of 90Sr from radioactive wastewater not only is essential for human public health and environmental remediation but also bears importance for alternate medical and industrial applications. Here, we report the facile synthesis of an open framework zinc thiostannate, Na5Zn3.5Sn3.5S13·6H2O (ZnSnS-1), templated by hydrated pentasodium clusters. This compound exhibits an effective and rapid ion exchange property for Sr2+ ions. The exchange kinetics conforms to a pseudo-second-order model, implying that the chemical adsorption of Sr2+ may be the rate-determining step. According to the Langmuir-Freundlich isotherm, the maximum exchange capacity of ZnSnS-1 for Sr2+ is 124.2 mg/g and ranks ahead of those of all the reported metal sulfide Sr2+ adsorbents. High exchange performance is observed over the broad pH range 2.5-13, although it could be inhibited to some extent by coexisting ions, especially Na+ and Ca2+. ZnSnS-1 shows a higher affinity for Sr2+ compared to Cs+, and the performance is almost unaffected by the presence of coexisting Cs+ even in excess amounts. Importantly, the Sr2+ in the exchanged product can be conveniently eluted by a concentrated KCl solution, and the recycled exchanger can be further used for Sr2+ exchange. These advantages combined with the robust framework for recycling concerns make ZnSnS-1 a highly promising exchanger for removal of radioactive Sr from the liquid nuclear waste.

Selenidostannates and a Silver Selenidostannate Synthesized in Deep Eutectic Solvents: Crystal Structures and Thermochromic Study.

Deep eutectic solvents (DESs) have been adopted as reaction media for solvothermal synthesis of crystal materials. In the present work, we extended the scope of DESs in chalcogenidometalate preparation by including dimethylamine, ethylamine, and trimethylamine hydrochlorides and synthesized a series of novel Sn-Se and Ag-Sn-Se compounds: i.e., [NH2(CH3)2]2Sn3Se7·0.5NH(CH3)2 (1), [NH4]2Sn4Se9 (2), [NH3C2H5]2Sn3Se7 (3), and [NH4]3AgSn3Se8 (4). Compounds 1 and 3 possess honeycomb lamellar [Sn3Se7] n2 n- structures featuring large hexagonal windows, while compound 2 features a rare [Sn4Se9] n2 n- anionic layer consisting of tetrameric {Sn4Se10} clusters as secondary building units (SBUs). Compound 4 comprises infinite [AgSn3Se8] n3 n- chains built by {Sn3Se8} units with Ag+ linkers, and it represents the first heterometallic chalcogenide synthesized in DESs. The organic ammonium cations of halide salts or in situ formed ammonium cations from the decomposition of urea act as templating agents for the formation of the inorganic frameworks. Compound 4 exhibits a marked thermochromic performance in the visible light range owing to the negative temperature dependence of its band gap ( Eg = 2.305-2.119 eV in the range of 100-450 K). The gold-dark red-gold color change is highly reversible in five rounds of heating and cooling, without any phase transition of the material, shedding light on the consequent device innovations.

Stepwise Conversion from GeO2 to [MGe4S10]n3n- (M = Cu, Ag) Polymer via Isolatable [Ge2S6]4- and [Ge4S10]4- Anions by Virtue of Templating Technique.

Rational synthesis of inorganic matter remains a great challenge encountered with modern synthetic chemistry. Here we reported the stepwise solvothermal conversion from GeO2 to [MGe4S10]n3n- (M = Cu, Ag) polymer via isolatable [Ge2S6]4- and [Ge4S10]4- anions by virtue of templating technique. The facile sulfuration of GeO2 resulted in the methylammonium-templated dimeric thiogermanate [CH3NH3]4Ge2S6 (1). This was used subsequently as a precursor for the formation of adamantane-like [Ge4S10]4- cluster, which was isolated as a mixed methylammonium/ethylammonium salt [CH3CH2NH3]3[CH3NH3]Ge4S10 (2). Compound 2 was then successfully used as a precursor to react with Cu+ and Ag+ cations in the presence of tetraethylammonium, resulting in alternating copolymeric products [(CH3CH2)4N]3MGe4S10 (M = Cu (3), Ag (4)), whose anionic moieties feature a novel zigzag chainlike structure constructed by [Ge4S10]4- clusters via two-coordinate Cu+/Ag+ linkers. Mixed amine/ethanol or deep eutectic solvents were applied as media for the syntheses of 1-4, and all the products were characterized in the solid state and solution. Crystal structural analysis of the title compounds revealed significant templating roles of the alkylammonium cations as both space-filling agents and hydrogen-bonding donors, suggesting the structure-directing mechanism for the species formation and crystal growth. The design and optimization of multistep structural conversion upon templating effects would be beneficial for drawing rational, predictable pathways for inorganic synthesis.

Combination of Metal Coordination Tetrahedra and Asymmetric Coordination Geometries of Sb(III) in the Organically Directed Chalcogenidometalates: Structural Diversity and Ion-exchange Properties.

Chalcogenidometalates exhibit rich and diverse structures and properties applicable to ion exchange, thermoelectrics, photocatalysis, nonlinear optics, and so on. This personal account summarizes our recent progress in constructing chalcogenidometalates by combining metal coordination tetrahedra and the asymmetric coordination geometries of Sb(3+) in the presence of organic species (typically organic amines and metal-organic amine complexes), which has been demonstrated as an effective strategy for synthesizing chalcogenidometalates with diversified structures and interesting properties. The linkage modes of asymmetric SbQn (n = 3, 4) geometries and group 13 (or 14) metal coordination tetrahedra are analyzed, and the secondary building units (SBUs), with different compositions and architectures, are clarified. The crucial role and function of organic species in the formation of chalcogenidometalates are explored, with an emphasis on their powerful structure-directing features. In particular, some chalcogenidometalates in this family exhibit excellent ion-exchange properties for Cs(+) and/or Sr(2+) ions; the factors affecting ion-exchange properties are discussed to understand the underlying ion-exchange mechanism.

Ln12 -Containing 60-Tungstogermanates: Synthesis, Structure, Luminescence, and Magnetic Studies.

A new class of hexameric Ln12 -containing 60-tungstogermanates, [Na(H2 O)6 ⊂Eu12 (OH)12 (H2 O)18 Ge2 (GeW10 O38 )6 ](39-) (Eu12 ), [Na(H2 O)6 ⊂Gd12 (OH)6 (H2 O)24 Ge(GeW10 O38 )6 ](37-) (Gd12 ), and [(H2 O)6 ⊂Dy12 (H2 O)24 (GeW10 O38 )6 ](36-) (Dy12 ), comprising six di-Ln-embedded {ß(4,11)-GeW10 } subunits was prepared by reaction of [α-GeW9 O34 ](10-) with Ln(III) ions in weakly acidic (pH 5) aqueous medium. Depending on the size of the Ln(III) ion, the assemblies feature selective capture of two (for Eu12 ), one (for Gd12 ), or zero (for Dy12 ) extra Ge(IV) ions. The selective encapsulation of a cationic sodium hexaaqua complex [Na(H2 O)6 ](+) was observed for Eu12 and Gd12 , whereas Dy12 incorporates a neutral, distorted-octahedral (H2 O)6 cluster. The three compounds were characterized by single-crystal XRD, ESI-MS, photoluminescence, and magnetic studies. Dy12 was shown to be a single-molecule magnet.

Ti2-Containing 18-Tungsto-2-Arsenate(III) Monolacunary Host and the Incorporation of a Phenylantimony(III) Guest.

The novel Ti2-containing, sandwich-type 18-tungsto-2-arsenate(III) [(Ti(IV)O)2(α-As(III)W9O33)2](14-) (1) was successfully synthesized by the reaction of [TiO](2+) species with [α-As(III)W9O33](9-). The monolacunary polyanion 1 is solution-stable, and a further reaction with 1 equiv of phenylantimony(III) dichloride resulted in [C6H5Sb(III)(Ti(IV)O)2(α-As(III)W9O33)2](12-) (2). Both polyanions 1 and 2 were structurally characterized in the solid state and solution. Electrochemical studies were also performed on both polyanions.

Open-framework hybrid zinc/tin selenide as an ultrafast adsorbent for Cs+, Ba2+, Co2+, and Ni2.

Efficient adsorption of radioactive 137Cs+ and 60Co2+ and their decay products 137Ba2+ and 60Ni2+ bears significance for hazard elimination in case of nuclear emergency, which relies on the adsorption rate enhancement that takes advantages of compositional and structural optimization. Herein, we report a zinc-doped selenidostannate constructed from T2-supertetrahedral clusters, namely K3.4(CH3NH3)0.45(NH4)0.15Zn2Sn3Se10·3.4 H2O (ZnSnSe-1K). The soft Se and micro-porosity synergistically endow this material with a binding affinity to Cs+, Ba2+, Co2+, and Ni2+ ions and ultrafast kinetics with R > 97.6% in 2-60 min. In particular, ZnSnSe-1K can remove 99.34% of Cs+ in 2 min (KdCs > 1.5 × 105 mL g-1), contributing to a record rate constant k2 of 9.240 g mg-1 min-1 that surpasses all metal chalcogenide adsorbents. ZnSnSe-1K exhibits good acid/base tolerance (pH = 0-12), and the adsorption capacities at neutral are 253.61 ± 9.15, 108.94 ± 25.32, 45.76 ± 14.19 and 38.49 ± 2.99 mg g-1 for Cs+, Ba2+, Co2+, and Ni2+, respectively. The adsorption performances resist well co-existing cations and anions, and the removal rates can keep above or close to 90% even in sea water. ZnSnSe-1K is employed in continuous column and membrane filtration, both of which shows excellent elimination efficiency (R > 99%) for mixed Cs+, Ba2+, Co2+, and Ni2+. Especially, the membrane with an ultrathin (70 µm) ZnSnSe-1K layer can remove 97-100% Cs+ in suction filtration with a short contact time of 0.33 s. Combined with the simple synthesis, facile elution and great irradiation resistance, ZnSnSe-1K emerges as a selenide adsorbent candidate for use in environmental remediation especially that involving nuclear waste disposal.

A gradient Sn4+@Sn2+ core@shell structure induced by a strong metal oxide-support interaction for enhanced CO2 electroreduction.

Oxidation states of Sn in tin oxides are hard to regulate due to the uncontrollable evolution during the electrochemical CO2 reduction reaction (CO2RR), thus limiting the adsorption capabilities and reaction kinetics. Herein, we propose a metal oxide-support interaction-mediated strategy to modify the electronic properties of tin oxides. A gradient Sn4+@Sn2+ core@shell structure was formed as a result of electron transfer from g-C3N4 to anchored SnO2, unlike reduced graphene oxide (rGO)-supported SnO2 with Sn4+-rich surfaces. Such unique structures were revealed by the depth profiles of X-ray photoelectron spectra, and they enhanced the adsorption and stabilization of the *CO2˙- intermediate and accelerated the reaction kinetics. Consequently, SnO2/g-C3N4 delivered a faradaic efficiency of 95.1% for the C1 products at -1.06 V, exceeding those of SnO2/rGO and most reported catalysts. Moreover, the performances were sustained for 70 h without obvious degradation. This work offers an alternative route to efficient catalyst design by combining oxidation state regulation and metal oxide-support interaction and contributes to the development of sustainable technologies for achieving carbon neutrality.

Efficient removal of Ba2+, Co2+ and Ni2+ by an ethylammonium-templated indium sulfide ion exchanger.

Removal of radioactive 133Ba, 60Co and 63Ni and their nonradioactive isotopes through ion exchange method would be highly beneficial for the safe disposal of liquid industrial waste, and it also bears importance for the emergency response to nuclear accident. Herein, we report the employment of an indium sulfide [CH3CH2NH3]6In8S15 (InS-2) with exchangeable ethylammonium cations for efficient and selective uptake of Ba2+, Co2+ and Ni2+. The corner-sharing linkage of P1-{In8S17} clusters in InS-2 endow the layered structure with nanoscale windows, which facilitates both transfer and accommodation of the large hydrated divalent metal ions. This results in ultrafast exchange kinetics (10-20 min) and top-level exchange capacities of 211.73 mg g-1 for Ba2+, 103.57 mg g-1 for Co2+, and 111.78 mg g-1 for Ni2+. Particularly, InS-2 achieves ultrahigh Kd values of 2.3 × 105 mL g-1 for Ba2+, 2.0 × 105 mL g-1 for Co2+ and 1.6 × 105 mL g-1 for Ni2+, corresponding to remarkable removal efficiencies larger than 99.4% (C0 ~ 6 ppm). InS-2 shows high ß and γ irradiation resistance, wide pH durability (pH 3-13 for Ba2+, pH 3-11 for Co2+ and Ni2+), and outstanding selectivity against competitor ions (e.g. Na+, K+, Mg2+, Ca2+). The InS-2-filled ion exchange column exhibits a fantastic removal effect (R > 99%) for mixed Ba2+, Co2+, Ni2+, as well as Sr2+. The ultralong column-treatment on 20000 BVs of flow reveals an affinity order of Co2+ > Ni2+ > Ba2+ > Sr2+ for InS-2, which gives deep insights into the adsorption process and interaction between competitor ions. This excellent uptake of Ba2+ (Ra by analogy), Co2+ and Ni2+ ions by InS-2 highlights the great potential of metal chalcogenides as a type of promising materials for minimizing contamination in complex wastewater.

Di-lacunary [In6S15]12- cluster: the building block of a highly negatively charged framework for superior Sr2+ adsorption capacities.

In this study, the construction of a highly negatively charged layered material [CH3CH2NH3]6In6S12 (InS-1) by introducing a lacunary cluster as the building block is reported. The pronounced framework negative charge density (5.59 × 10-3) and the soft Lewis basic S component endow InS-1 with an effective ion exchange performance toward heavier Sr2+, with a top-level adsorption capacity qm of 105.35 mg g-1. InS-1 exhibits a good exchange activity over pH 3-12, and the Sr2+-laden product can be facilely eluted.

Deep eutectic solvothermal synthesis of an open framework copper selenidogermanate with pH-resistant Cs+ ion exchange properties.

Presented here is the deep eutectic solvothermal synthesis of an open framework copper selenidogermanate, namely [NH3CH3]0.75Cu1.25GeSe3 (CuGeSe-1), which exhibits a rapid and effective Cs+ ion exchange performance (qm = 225.3 mg g-1). CuGeSe-1 shows a structural flexibility upon Cs+ exchange. The robust selenide-based framework contributes to an excellent pH stability (1-12). The Cs+-laden product could be facilely eluted.

Preparation of thermochromic selenidostannates in deep eutectic solvents.

Deep eutectic mixtures were deployed for the preparation of porous layered [Sn3Se7]n2n- single crystals. The perforation on the layers accentuates the negative temperature dependence of its band gap, resulting in remarkable thermochromic performance. Substitution of the hydroxo group by the methyl group provides an enhanced hydrophobicity for the organic template, leading to an anhydrous product with a remarkably improved thermal stability and thus reversible thermochromic properties.

A hybrid with uniaxial negative thermal expansion behaviour: the synergistic role of organic and inorganic components.

Presented is an inorganic-organic hybrid compound Mn2(api)Sb2S5 (1) with uniaxial NTE behaviour. The NTE of reflects a strong synergistic role of organic and inorganic components, which results from the novel zigzag linkage of interlamellar organic ligands. An "elevator-platform" expansion mechanism was proposed, with implications for future design of sensitive hybrid thermomechanical actuators.

Ti7-containing, tetrahedral 36-tungsto-4-arsenate(III) [Ti6(TiO6)(AsW9O33)4]20-.

We have prepared the Ti7-containing, tetrahedral 36-tungsto-4-arsenate(III) [Ti6(TiO6)(AsW9O33)4](20-) (1) by a simple, one pot procedure. Polyanion 1 contains a novel Ti7-core, comprising a central TiO6 octahedron surrounded by six TiO5 square-pyramids, and capped by four {As(III)W9} trilacunary fragments. The title polyanion is solution-stable, as shown by (183)W NMR and mass spectrometry, and exhibits interesting biological properties.

[Preparation bimetallic heterogeneous Fenton-like catalyst as sepiolite supported and its surface chemical characterization].

The reactive brilliant blue was chosen as the probe pollutant. Fe(NO3)3 concentration, MnSO4 concentration, urea concentration, water bath temperature, calcined temperature and time were as influencing factors, the process parameters of homogeneous precipitation method was optimized for the preparation of bimetallic heterogeneous Fenton-like catalyst as modified sepiolite supported. At the same time, surface chemical characteristics of catalyst were analyzed by SEM, FTIR and XRD. Results showed that: with increasing iron ion concentrations, the active ingredient of the catalyst increased. Adding small amount of manganese ion could inhibit the growth of Fe2O3 diameter and increase the activity of the catalyst. Urea concentration was increased, so that the higher the urea concentration, the higher rate of formation of crystal gains, was conducive to generate small and uniform particles. The optimal conditions were found for preparing bimetallic heterogeneous Fenton-like catalyst by Box-Behnken experiment, which were as follows: concentration of Fe(NO3)3, MnSO4 and urea were 0.18 mol x L(-1), 0.05 mol x L(-1) and 1.0 mol x L(-1), respectively. The dosage of the modified sepiolite was 40 g x L(-1) and water bath temperature was 100 degrees C. Additionally, the catalyst was calcined at 370 degrees C for 3 h. The SEM showed that the sepiolite was an a-type sepiolite, which could be used as a well catalyst support. The infrared spectrum presented the bend vibrations of the Fe-O stretch vibration. The XRD patterns of the catalysts showed the characteristic diffraction peaks of alpha-Fe2O3, and gamma-Fe2O3.