Dimensional Metal-organic Framework Research Articles

Effective reduction of 4-nitrophenol with Au NPs loaded ultrathin two dimensional metal-organic framework nanosheets

The catalysis performance of noble metal nanoparticles always suffered from harsh aggregation during reaction hence promising supports that were able to restrict as well disperse the NPs were in great demand. Herein we reported a bottom-up synthesis of ultrathin two dimensional ferrocene based metal-organic framework (FMOF) nanosheets employing ZrCl4 and 1,1′-ferrocene-dicarboxylic acid as metal nodes and organic ligands respectively. Employed as a stable and easy-contacted support, Au NPs were reduced and attached on the surface of FMOF nanosheets with average diameter of ca. 5 nm. The obtained Au/MOF composite was used in the reduction of 4-nitrophenol to 4-aminophenol, and rapid conversion of almost 100% could be achieved in 5 min with a maximum TOF of 10.9 × 10−4 mol min−1 m2. Moreover, after 10 cycles of the reusability test, there was no obvious decline in catalytic performance with conversion of almost 100%, confirming the unprecedented stability of this Au-MOF composite.

Two dimensional (2D) molecular frameworks for rapid and selective adsorption of hazardous aromatic dyes from aqueous phase

Herein, two dimensional metal organic frameworks, [M(ox)(bpy)]n [H2ox = oxalic acid, bpy = 4,4′-bipyridine and M = Cu (1) or Co(2)] are designed under solvothermal condition and characterized thoroughly by FTIR, PXRD, TGA and single crystal X-ray studies. X-ray structure along with topological analysis reveals a two dimensional (2D) framework of the present material with sql topology with metals in square bipyramidal geometry. The two MOFs are employed for adsorption of organic dyes i.e. methylene blue (MB) and methyl orange (MO) considered widely as water pollutants. Interestingly, the molecular frameworks showed selective nature towards methylene blue, the cationic dye. The framework remains stable after adsorption of dye and can be recycled up to five times. At equilibrium, the removal percentage of MB by the frameworks is ultimate (96–98%) with optimum temperature (25 °C) and pH (neutral). The kinetic studies are suggestive of the adsorption to proceed via pseudo second order reaction. The key factors or mechanism for enhanced adsorption of MB are electrostatic, π-π and hydrogen-bonding interactions existing between the 2D sheets and the dye. Thus, fine structural tuning of the easy-to-prepare two dimensional frameworks could lead to adsorb and remove the hazardous organic aromatic pollutants with high efficiency at low cost in future endeavours.

Metal-organic frameworks (MOFs) and MOFs-derived CuO@C for hydrogen generation from sodium borohydride

Hydrogen gas has been considered as one of the promising sources of energy. Thus, several strategies including the hydrolysis of hydrides have been reported for hydrogen production. However, effective catalysts are highly required to improve the hydrogen generation rate. Two dimensional metal-organic frameworks (copper-benzene-1,4-dicarboxylic, CuBDC), and CuBDC-derived CuO@C were synthesized, characterized and applied as catalysts for hydrogen production using the hydrolysis and methanolysis of sodium borohydride (NaBH4). CuBDC, and CuO@C display hydrogen generation rate of 7620, and 7240 mlH2·gcat−1· min−1, respectively for hydrolysis. While, CuBDC offers hydrogen generation rate of 9060 mlH2·gcat−1· min−1 for methanolysis. Both catalysts required short reaction time, and showed good recyclability. The materials may open new venues for efficient catalyst for energy-based applications.

Preparation of Micro and Nanorod Metal Organic Framework Through Coordination Modulation Method as Precursor for Micro and Nanorod NiO

In the present work, micro and nanorods of a three dimensional metal organic framework, [Ni2(BDC)2(DABCO)]·DMF4·H2O4(1), DABCO (DABCO = 1,4-diazabicyclo[2.2.2] octane), and BDC (BDC = 1,4-benzenedicarboxylic acid), were synthesized through coordination modulation method in the presence of various amounts of acetic acid. Then the effect of acetic acid amount on the size of the synthesized materials was investigated. The prepared micro and nanorods characterized by X-ray powder diffraction (PXRD), BET surface area, field emission scanning electron microscopy (FE-SEM), and FT-IR spectroscopy. Characterizations revealed that acetic acid acts as an efficient modulator and in its optimized amount (r = 25, 30 ratio of acetic acid to BDC) nanorods with the diameter in the range of 80–200 nm were obtained. While, the diameter of synthesized MOFs in unoptimized amount of modulator was in the range of 2–5 µm. Thermal decomposition of micro and nanorods of compound 1 at 600 °C under air for 4 h led to micro and nanorods NiO, respectively. The FE-SEM images demonstrate the size of NiO depends on the size of compound 1 particles.

DFT study of the two dimensional metal–organic frameworks X3(HITP)2 as the cathode electrocatalysts for fuel cell

The search for cheap, stable, and more active oxygen reduction reaction (ORR) catalysts is of great significance to proton exchange membrane fuel cells, and two-dimensional metal–organic frameworks with metal–nitrogen active sites are attracting increasing attention. The ORR mechanisms on X3(HITP)2 (X = Cr, Mn, Fe, Co, Rh, Os, Ir) catalysts are studied by density functional theory. All possible adsorption sites are explored, and the central metals rather than hydrogen or carbon atoms are demonstrated as the most favorable catalytic sites, completely different from the case of the well-known Ni3(HITP)2. The predicted ORR activities of X3(HITP)2 follow the order of Ir3(HITP)2, Rh3(HITP)2, Co3(HITP)2, Fe3(HITP)2, Os3(HITP)2, Cr3(HITP)2, and Mn3(HITP)2, during which the first two have the highest onset potential of 0.92 and 0.86 V, respectively. This result uncovers that the ORR behavior of X3(HITP)2 can be engineered by substituting the central metals. The linear relationships between the adsorption energies of O2, OOH, O and that of OH species illustrate that the adsorption strength of OH can be used as the activity descriptor for the current X3(HITP)2. Ir3(HITP)2 and Rh3(HITP)2 not only have good ORR activities and stabilities, but also have high anti-poison abilities to some impurity gases, as well as CH3OH molecule.

Synthesis, X-ray crystal structure and spin polarized DFT study of high spin Mn based metal-organic framework

Theoretical modeling of the geometries of metal-organic frameworks is quite challenging. In order to compare the geometry obtained through density functional theory (DFT) calculations with the one obtained experimentally, a hydrothermal reaction of the potassium salt of 1,1-cyclopentane diacetic acid (L) with MnCl2·2H2O in the presence of 4,4′-bipyridine (bpy) was carried out which formulated a two dimensional metal-organic framework [Mn2(L)2(bpy)2(H2O)2]n∙6H2O. Single crystal X-ray diffraction analysis reveals that the compound crystallized in the centrosymmetric monoclinic space group P 2/n. The presence of solvate water molecules of crystallization offer hydrogen bond formation and result the connection of 2-D sheets into 3-D hydrogen bonded metal-organic framework. The manganese atom can have a maximum of sextet spin state (five unpaired electrons). Single point energies were calculated at M05-2X/6-31G (d,p) for different spin states (up to 11 et) of the high energy framework and it was elucidated that the 11et spin stat is the lowest energy spin state.

Lanthanide(Tb3+, Eu3+)-functionalized a new one dimensional Zn-MOF composite as luminescent probe for highly selectively sensing Fe3+

A new one dimensional zinc metal organic framework {[Zn(NDIC)·2H2O]·2H2O}n (NDIC = 5-(5-Norbonene-2,3-dicarboximide)Isophthalic acid) has been synthesized under an hydrothermal condition and chosen as a parent framework to sensitize via encapsulating Tb3+ and Eu3+ cations in Zn-MOF. The obtained composite Tb(3+)@Zn-MOF shows excellent luminescence which performs a remarkable quenching effect in the luminescence emission of Tb3+ upon the introduction of Fe3+. Subsequently, Tb(3+)@Zn-MOF as a highly selective and sensitive sensor for Fe3+. Most importantly, the luminescence probe of Fe3+ shows a low detection limit (7.5 × 10−6 M), a broad linear range (2.5 × 10−6–7.5 × 10−5). A paper strip coated with Tb(3+)@Zn-MOF material was also shown to be highly selective for Fe3+ and under the irradiation of UV light of 254 nm by the naked eyes. This is first example for detecting metal ions based on a lanthanide functionalized a new Zn metal–organic framework.

Vertically co-oriented two dimensional metal-organic frameworks for packaging enhanced supercapacitive performance

Metal–organic frameworks (MOFs) are promising materials for batteries and supercapacitors. However, random crystal orientations and low conductivity can result in poor performance. Designing a convenient method to address these issues is therefore an important challenge. Here we describe an efficient strategy to fabricate self-supported MOF wall-like architectures with uniform orientation on carbon nanowalls (CNWs) as seedbeds. In addition, we gain molecular-level insight into the interface between CNWs and MOF nanosheets using density functional theory calculations. Our results suggest that assembled ions anchor on edge carbon atoms to match the matrix of the edges of CNWs, while the remaining ions self-assemble with terminal –COOH groups on p-benzenedicarboxylic acid ligands to form the structure. Our findings demonstrate a feasible method to fabricate integrated MOF electrodes with ideal orientations and, therefore, may pave the way to unlock the inherent high performance of MOF materials towards a number of engineering applications.

A two dimensional metal–organic framework nanosheets-based fluorescence resonance energy transfer aptasensor with circular strand-replacement DNA polymerization target-triggered amplification strategy for homogenous detection of antibiotics

In the study, a novel two dimensional metal–organic framework (Cu-TCPP nanosheets) based fluorescence resonance energy transfer (FRET) aptasensing platform was developed for detecting antibiotics. Cu-TCPP nanosheets were employed for quenching the background fluorescence and circular strand-replacement DNA polymerization (CSRP) for signal amplification. To fulfill the purpose, we designed an aptamer hairpin probe (HP) whose stem can be opened while specifically binding to target. Then the opened HP would bind with the primer. Under the action of polymerase, extension reaction was induced to generate double-stranded DNA (dsDNA), and then the target was released for the next cycle. Finally, SYBR Green I (SG) can bind with dsDNA to produce strong fluorescence response for quantification of target. It's worth mentioning that the fluorescence of HP/SG complex and free SG could be completely quenched by Cu-TCPP nanosheets while that of dsDNA/SG complex wouldn't be affected. Thus, the sensor produced negligible background signals. It can produce 7.5-fold improved S/N compared to a graphene oxide (GO)-based FRET aptasensor. Chloramphenicol (CAP) was chosen as the model analyte to demonstrate the feasibility of the sensor system. The detection range is broad from 0.001 to 10 ng mL−1 with a detection limit down to 0.3 pg mL−1. The proposed assay was label free and can be used in homogenous detection which greatly simplifies the complexity of operations. The strategy opens a new way to develop sensitive, in-situ and simple assay for antibiotics in foods.

Versatile Surface Functionalization of Metal–Organic Frameworks through Direct Metal Coordination with a Phenolic Lipid Enables Diverse Applications

AbstractA novel strategy for the versatile functionalization of the external surface of metal‐organic frameworks (MOFs) has been developed based on the direct coordination of a phenolic‐inspired lipid molecule DPGG (1,2‐dipalmitoyl‐sn‐glycero‐3‐galloyl) with metal nodes/sites surrounding MOF surface. X‐ray diffraction and Argon sorption analysis prove that the modified MOF particles retain their structural integrity and porosity after surface modification. Density functional theory calculations reveal that strong chelation strength between the metal sites and the galloyl head group of DPGG is the basic prerequisite for successful coating. Due to the pH‐responsive nature of metal‐phenol complexation, the modification process is reversible by simple washing in weak acidic water, showing an excellent regeneration ability for water‐stable MOFs. Moreover, the colloidal stability of the modified MOFs in the nonpolar solvent allows them to be further organized into 2 dimensional MOF or MOF/polymer monolayers by evaporation‐induced interfacial assembly conducted on an air/water interface. Finally, the easy fusion of a second functional layer onto DPGG‐modified MOF cores, enabled a series of MOF‐based functional nanoarchitectures, such as MOFs encapsulated within hybrid supported lipid bilayers (so‐called protocells), polyhedral core‐shell structures, hybrid lipid‐modified‐plasmonic vesicles and multicomponent supraparticles with target functionalities, to be generated. for a wide range of applications.

Two novel isostructural and heteroleptic Nd(III) and Dy(III)-organic frameworks constructed by 2,5-pyridinedicarboxylic acid and in situ generated 2-pyridinecarboxylic acid: Hydrothermal synthesis, characterization, photoluminescence properties and heterogeneous catalytic activities

The crystal structures, heterogeneous catalytic activities and photoluminescent properties of two novel three dimensional (3D) metal organic frameworks (MOFs), [Nd(pyc)(pydc)(H2O)]n (1) and [Dy(pyc)(pydc)(H2O)]n (2) (H2pydc=pyridine-2,5-dicarboxylic acid, Hpyc=2-pyridinecarboxylic acid) are presented. The synthesized complexes under hydrothermal conditions were characterized by the elemental analysis, inductively coupled plasma (ICP), fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), single crystal X-ray diffraction and powder X-ray diffraction (PXRD) analysis. For morphological analysis, field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) were used. The compounds are isostructural and each Ln3+ (Nd(III) and Dy(III)) centers are eight-coordinated. MOFs have the distinct 3D open-framework architectures due to the presence of Hpyc ligands, which are converted from H2pydc ligands in-situ decarboxylation under the hydrothermal conditions. Photoluminescence properties and thermal stabilities of the compounds have been investigated. Their heterogeneous catalytic activities have also been examined on the oxidation of the thymol (T) to thymoquinone (TQ). The structures of the MOFs were stable after three catalytic cycles. The maximum T conversion values, 40.37% and 36.45% were recorded with nearly 100% selectivities by using 1 and 2, respectively.

Three dimensional porous Hofmann clathrate [MIIPtII(CN)4]∞ (M = Co, Ni) synthesized by using postsynthetic reductive elimination.

We synthesized cyano-bridged three dimensional metal-organic frameworks [MII(H2O)2PtIV(CN)4Br2]∞·n(H2O) (1: M = Co, 2: M = Ni) with an NbO type topology. Although 1 and 2 have no accessible pores, these MOFs were found to undergo reductive elimination of the axial bromides on the PtIV ions as well as removal of water molecules upon heating to form porous [MIIPtII(CN)4]∞ (1': M = Co, 2': M = Ni) with retention of their crystallinity.

Two (5,5)-connected isomeric frameworks as highly selective and sensitive photoluminescent probes of nitroaromatics

Herein we report the first two (5,5)-connected isomeric frameworks, namely, (Me2NH2)[Zn2L(H2O)]·3.5DMF (1) and (Me2NH2) [Zn2L(H2O)]·6DMF·4H2O (2) (DMF = dimethylformamide, H5L = 5,5′-(6-(4-carboxyphenylamino)-1,3,5-triazine-2,4-diyldiimino) diisophthalic acid), obtained via assembly reactions between Zn2+ and a semi-rigid pentacarboxylate ligand (L5−). Single-crystal X-ray diffraction analyses reveal that both compounds are three dimensional metal–organic frameworks (MOFs) built of the same {Zn2(CO2)5} molecular building blocks (MBBs) and L5− ligands but have different topologies (point symbols of (44·66) and (46·64)(46·64) for 1 and 2, respectively). The mechanisms of the selective and efficient quenching of their photoluminescence (PL) by a series of nitroaromatic (NACs) solutions could be explained by electron transfer, long range energy transfer and/or electrostatic interactions. Remarkably, 1 and 2 can impressively detect the concentrations of dinoseb in solutions down to 0.09 and 0.11 ppm, respectively. Their PL could also be quenched by nitrobenzene (NB) and 4-nitrotoluene (4-NT) vapors, and the emission from 2 can be more quickly quenched than that from 1 possibly due to 2's larger pores and faster uptake of NAC vapors. 1 and 2 demonstrate significantly better performances than the two previously reported 4-connected MOFs using Zn2+ and a ligand isomeric to L5− in detecting NACs in both suspension and vapour mainly due to the ligands' different LUMOs and arrangements of carboxylate groups (L. Di, J. J. Zhang, S. Q. Liu, J. Ni, H. Zhou and Y. J. Sun, Cryst. Growth Des., 2016, 16, 4539). This work sheds light on not only understanding of the formation of framework isomers but also the development of MOF-based NAC probes with better performances via judicious selection of suitable ligands.

Novel 2D micro-porous Metal-Organic Framework for hydrogen storage

A novel two dimensional Metal-Organic Framework (MOF) structured compound with trimesic acid (TMA), 1,10 Phenantroline (Phen) and Cu(II) building blocks were synthesized and characterized experimentally. Then Grand Canonical Monte Carlo (GCMC) simulation calculations used for determination of hydrogen adsorption capacity and surface characteristics of the compound theoretically. Three different regions were determined for the adsorbent, which were micro, micro/sub-meso spaces inside the adsorbent and the surface regions. It is found that the synthesized compound could uptake approx. 1.3 and 1.2 wt.% hydrogen at 77 K, 100 bars and 1 bar respectively. Thus the adsorbent that is synthesized in this work have strong hydrogen adsorption capability in comparison to the previously reported ones.

Reactions of metal salts with bronsted acidic ionic liquid: Formations of imidazole template metal sulfates or imidazole-metal complexes

The reactions of metal salts with Bronsted acidic ionic liquid [HMIM][HSO4] in ethanol were investigated. Zr(OPr)4, ZnCl2 or MnCl2 reacted with [HMIM][HSO4] via an anion exchange and resulted in the formation of imidazole template sulfates [HMIM]2Zr[SO4]3[DMSO]2 (1), [HMIM]2Zn[SO4]2 (2) and [HMIM]2Mn[SO4]2 (3), respectively. On the other hand, Cu(OAc)2 interacted with imidazole to form an imidazole-Cu complex [MIM]4Cu[HSO4]2 (4). The imidazole template sulfates present various crystal structures, in which [HMIM]2Zr[SO4]3[DMSO]2 (1) has zero dimensional monomeric structure made up of [Zr(SO4)3(DMSO)2]2− anions and [HMIM]+ cations. While, [HMIM]2Zn[SO4]2 (2) and [HMIM]2Mn[SO4]2 (3) exhibit one dimensional metal–organic framework which consist of infinite linear chains linked by SO4 units. Compound 4 is an imidazole-metal complex, in which four imidazoles coordinate to Cu(II) to form tetragonal structure compensating the charges with protonated sulfates. Additionally, the magnetic property of compound 3 is investigated to find that it presents a weak antiferromagnetic property probably due to the coupling interactions between the neighboring Mn(II) centers.

Mixed ligand two dimensional Cd(ii)/Ni(ii) metal organic frameworks containing dicarboxylate and tripodal N-donor ligands: Cd(ii) MOF is an efficient luminescent sensor for detection of picric acid in aqueous media.

Two dimensional metal organic frameworks (MOFs) [Cd(5-BrIP)(TIB)]n () and [Ni2(5-BrIP)2(TIB)2]n (), involving the aromatic polycarboxylate ligand 5-bromo isophthalic acid (H2BrIP), flexible tripodal ligand 1,3,5-tris(imidazol-1-ylmethyl)benzene (TIB) and Cd(ii)/Ni(ii) metal nodes have been synthesized by different methods. These compounds were characterized by various analytical methods, and variable temperature X-ray diffraction data showed thermal stability of both MOFs up to 350 °C. Phase purity as well as water stability of the MOFs were established by powder X-ray diffraction, and the structural diversity of the compounds were investigated by single-crystal X-ray diffraction. Both the MOFs are mixed ligand 2D nets, and the topology of the network can be described as a binodal 3,5-c connected net with 3,5L2 topology having the point symbol {4(2)·6(7)·8}{4(2)·6}. Sensing of picric acid [2,4,6-trinitrophenol, TNP] by luminescence quenching among a large range of nitroanalytes in aqueous phase by the Cd(ii) luminescent MOF (LMOF) were been investigated. Structural studies on 1 : 1 co-crystals () of TIB and TNP were carried out. The selective and sensitive fluorescence quenching response of towards electron-deficient TNP over other nitro analytes in aqueous phase was demonstrated by fluorescence quenching titration. Concomitant occurrence of electron transfer/energy transfer processes and electrostatic interaction favours the selective sensing of TNP. A Cd(ii) LMOF ()-coated paper strip that we developed demonstrated fast and selective response to TNP, by the complete quenching of the blue fluorescence upon excitation of the paper strip at 365 nm radiation in its presence.

Interpenetrated Metal–Organic Frameworks with [Ag(CN)2]− Bridging Ligand: Synthesis, Structural Characterization and Magnetic Study

This report articulates synthesis and single-crystal structural characterization of two twofold interpenetrated three dimensional metal–organic frameworks [CoII(bipy)2{Ag(CN)2}2] n (1) and [CoII(bpee)2{Ag(CN)2}2] n (2) [bipy = 4,4′ bipyridine, bpee = 1,2-di(4-pyridyl)ethylene]. Single-crystal X-ray diffraction studies reveal that both 1 and 2 represent 3D pillared–layered framework with twofold interpenetration. The 2D network is constructed with CoII–AgI(CN)2–CoII corrugated layer, which is further pillared by the organic spacer (bipy and bpe for 1 and 2, respectively) to result the 3D structure. The magnetic property of 1 has also been investigated which shows mutual competition between ferromagnetic coupling and the single-ion anisotropy effect of Co(II) ions.

Metal–organic framework-based molecular beacons for multiplexed DNA detection by synchronous fluorescence analysis

We report a new sensor combined two dimensional metal-organic framework (MOF), N,N-bis(2-hydroxy-ethyl)dithiooxamidato copper(II) (H2dtoaCu), with the hairpin-structured oligonucleotides and demonstrate its feasibility in detecting multiplexed sequence-specific DNA. The key component of this sensor (MOF-MBs) is the hairpin-structured fluorescent oligonucleotide that allows the MOFs to function as both a "nanoscaffold" for the oligonucleotide and a "nanoquencher" of the fluorophore. An oligonucleotide sequence fragment of wild-type HBV (T1) and a reverse-transcription oligonucleotide sequence of RNA fragment of HIV (T2) were used as model systems. While in the presence of the targets, the fluorescence of dyes was recovered by forming a double strand structure. Multiplex DNA detection can be realized by synchronous scanning fluorescence spectrometry, and there was no cross reaction between the two probes. Under the optimum conditions, the fluorescence intensities of two dyes all exhibit good linear dependence on their target DNA concentration in the range of 1-10 nM with the detection limit of 0.87 nM and 0.22 nM for T1 and T2, respectively. As a proof of concept, the MOF-MBs have been successfully used as a potential sensing platform for simultaneous detection of multiplexed DNA.

Variation of CO2 adsorption in isostructural Cd(ii)/Co(ii) based MOFs by anion modulation

A potential multidentate tris-pyridyl ligand has been synthesized, and later employed for the tailoring of four isostructural cadmium(II)/cobalt(II) two dimensional (2D) metal organic frameworks, [[M(dmpt)2(X)2]·xS]n, where S = solvent, M = Cd2+, (X = NO3− (1), Br− (2), I− (3)); M = Co2+ (X = Cl− (4)), dmpt = 4′-(3,4-dimethoxyphenyl)-4,2′:6′,4′′-terpyridine. These complexes have been characterized by infrared (IR) spectroscopy, elemental analysis, thermogravimetric analysis (TGA) and powder X-ray diffraction (PXRD) and single crystal X-ray diffraction analyses. Single crystal X-ray diffraction analysis reveals that the complexes (1–4) are isostructural and crystallize in the monoclinic C2/c space group. They possess similar structural features such as metal-coordination environment, network topology, π⋯π interactions and exhibit a 2D uninodal 44-sql topology with slightly tuned cavities. In complexes 1–4, the [[M(dmpt)2(X)2]·xS] coordination monomer acts as the building block, building 2D layers which are further stacked up via Van der Waals interactions into a three-dimensional (3D) framework. The effect of weak interactions on the structural dynamics of the systems has also been studied. Furthermore, a gas adsorption study of these complexes demonstrates that they are affected by the impact of directing anions inside the pores.

Crystal structure, thermal decomposition, photoluminescence and magnetic studies of a new two dimensional metal–organic framework constructed from infinite chains of edge-sharing CeO6(H2O)2(NO3) polyhedron with bullet shaped channels

Abstract A new cerium–adipate metal–organic framework [Ce(C6H8O4)(H2O)2(NO3)] was grown by simple gel diffusion technique at room temperature. The compound possesses a two dimensional network structure constructed from edge sharing CeO6(H2O)2(NO3) polyhedron. The adjacent polyhedrons are connected by the carboxylate ligand forming the 2D framework with bullet shaped channels running parallel to c axis. Thermal decomposition of the compound takes place in four steps and CeO2 is obtained as the final product. UV–visible spectra, solid state photoluminescence, and magnetic susceptibility measurements were also carried out at room temperature.