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Eu-doped layered yttrium hydroxides sensitized by series of benzenedicarboxylate and sulphobenzoate anions
摘要： A number of Eu-doped layered yttrium hydroxides intercalated with various benzenedicarboxylate (phthalate, isophthalate and terephthalate) and sulphobenzoate (2-, 3- and 4-sulphobenzoate) anions was obtained using hydrothermal microwave (HTMW) treatment. For the first time, phthalate, isophthalate and sulphobenzoate anions were intercalated into layered rare-earth hydroxides (LRHs). Two approaches to the synthesis of intercalated layered yttrium hydroxides were used: ion exchange reactions and homogeneous hydrolysis of rare-earth cations in the presence of the intercalated anion. Ion-exchange reactions between layered rare-earth hydroxides and a series of benzenedicarboxylic and sulphobenzoic acid salts were performed under conditions of HTMW treatment, which significantly increased the rate of intercalation. The structure of the first representative of layered rare-earth hydroxides intercalated with sulphobenzoate-type anions, namely layered yttrium hydroxide intercalated with 4-sulphobenzoate of composition Y3(OH)7(C7H4O5S)·H2O, was solved. Intercalation of benzenedicarboxylate and sulphobenzoate anions into Eu-doped layered yttrium hydroxides led to a substantial sensitization of Eu3+ luminescence. The local symmetry of Eu3+ was greatly decreased by intercalation of benzenedicarboxylate and sulphobenzoate anions.
关键词： Layered rare-earth hydroxides,anion exchange,LRH,hydrothermal microwave treatment,luminescence,hybrid materials
更新于2025-11-21 11:20:42
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Electrical Properties of Fluoro-Substituted Perovskites Ba2 ? 0.5xCaNbO5.5 ?xFx
摘要： The effect of F--doping on the transport properties of perovskite-type complex oxides based on barium—calcium niobate Ba2CaNbO5.5 is analyzed. It is found that, regardless of the mechanism of introducing fluoride ions into the oxygen sublattice, the О2– and Н+ conductivities increase in the range of low fluoride concentrations due to an increase in the mobility of current carriers.
关键词： perovskite,anion doping,heterovalent doping,protonic conductivity,ionic conductivity
更新于2025-11-21 11:20:42
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Non-radiation creation of complex centers in wide-gap oxide crystals
摘要： It is shown that complex aggregate centers of oxygen divacancy type (F2 centers) and interstitial aluminum type near the anion vacancy (Ali+) are formed in anion-deficient crystals of corundum (α-Al2O3-δ) and beryllium oxide (BeO1-δ) under thermo-optical treatment (TOT). These centers are similar to those created in stoichiometric α-Al2O3 and BeO crystals under neutron irradiation. It is important to note that thermal stability of the TOT-created complex centers is higher than that of similar neutron-induced centers. It is also established that the probability of their formation is related to the temperature of the TOT, the wavelength of the stimulating light, and the initial anionic deficiency manifested as F+ and F centers (anion vacancies with one and two electrons, respectively).
关键词： Formation of complex defects,Wide-gap anion-deficient oxide crystals,Thermoluminescence,Optical absorption,Thermostability of complex defects,Thermo-optical treatment
更新于2025-11-19 16:56:35
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Stable, Color-Tunable 2D SCN-Based Perovskites: Revealing the Critical Influence of Asymmetric Pseudo-Halide on Constituent Ions
摘要： Two-dimensional (2D) layered perovskites (An+1BnX3n+1, n = 1, 2, …) have lately attracted significant research interest because of their enhanced ambient stability comparing to the conventional 3D counterparts. Beside the common A-site cation engineering, using an asymmetric pseudo-halide, SCN, anion in X-site anion has been recently proven as another effective approach to constitute 2D perovskite. Among them, 2D (MA)2Pb(SCN)2I2 was most widely investigated and honored as a promising material owing to its decent optoelectronic properties; however, its poor stability arouses concerns from the recent researches. In this study, a systematical composition engineering of A2Pb(SCN)2X2 (A= FA+, MA+, Cs+ and X= Br-, I-) was conducted. Our results revealed that linear SCN- anion may dictate critical restrictions on the constituent ions of its derived 2D framework (PbX4(SCN)2), which has not been extensively discussed yet. We demonstrated that using a smaller Cs+ cation can afford a more favorable 2D structure compared with the MA+ cation. Cs2Pb(SCN)2I2 was revealed to possess improved stability and photo-response compared to (MA)2Pb(SCN)2I2. Interestingly, Cs2Pb(SCN)2I2 and (MA)2Pb(SCN)2I2 seem to possess distinct electronic band structures as indicated by their discrepant photoluminescence spectra, for which the former exhibits a rather intense singlet emission at room temperature, as opposed to the latter having a dominant emission associated with triplet or defective states. Furthermore, using a smaller Cs+ cation also enables facile replacement of smaller halide anion. A series of mix-halide 2D Cs2Pb(SCN)2(I1-xBrx)2 (x = 0, 1/3, 1/2, 2/3, 1) with variant vivid color was explored by both calculation and experimental efforts to corroborate the further enhanced stability when x value increases. The results revealed in this work might be inherent trait of 2D SCN-based perovskites and also unveil that all inorganic 2D Cs2Pb(SCN)2X2 perovskite system is a promising class of material with decent stability and color-tunability, deserving further explorations.
关键词： stability,Cs cation,pseudo-halide,SCN- anion,color-tunability,2D perovskite
更新于2025-11-14 17:04:02
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Visible-light-triggered generation of persistent radical anions from perylenediimides: A substituent effect and potential application in photocatalytic reduction of Ag+
摘要： Three perylenediimide derivatives were reduced to their persistent radical anions in N-methyl-2-pyrrolidone (NMP) under ambient conditions by a visible light photoinduced electron transfer (PET). UV?vis and electron paramagnetic resonance (EPR) measurements were carried out to confirm the formation of radicals. The relationships between molecular structure, electrochemical property, phototransformation kinetics, and air stability of radical anions were investigated by the introduction of pyrimidine rings at the core position and fluoroalkylation substituents at the imide position. This study reveals that the electron-deficient pyrimidine rings and electron-withdrawing fluoroalkylation substituents can effectively enhance the phototransformation rate and the radical stability at ambient conditions. The effects of solvents and illuminance levels on the photoinduced reduction of perylenediimides were also studied. A photocatalytic reduction of Ag+ was successfully carried out using the perylenediimide with pyrimidine and fluoroalkylation substituents as catalyst upon irradiation with visible light.
关键词： Photocatalytic reduction,Perylene diimide derivative,Silver ion,Persistent radical anion,Visible light irradiation
更新于2025-11-14 17:03:37
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Voltage Stimulated Anion Binding of Metallo-Porphyrin Induced Crystalline 2D Nanoflakes
摘要： Voltage stimulated redox active materials received significant attention in the field of organic electronics and sensor technology. Consequently, such stimuli responsive materials triggered the formation of crystalline nanostructures facilitates the design of efficient smart devices hitherto unknown. Thus, we reported free base and metallo- tetratolylporphyrin linked ferrocene derivatives (H2TTP-Fc and ZnTTP-Fc) undergo distinct proton/anion binding mechanism in CHCl3 during bulk electrolysis at applied voltage of 1.4 V followed by nanospheres and crystalline 2D nanoflakes formation via MVD approach. Cyclic voltammetry and UV-Vis absorption studies of H2TTP-Fc and ZnTTP-Fc revealed the cation (H+)/anion (Cl-) binding affinity towards free ‘N’ atoms and Zn leads [H4TTP-Fc]+Cl- and H+[(Cl)ZnTTP-Fc]- thereby improvement in current and charge generation compared to initial state. SEM and TEM images revealed the nanospheres and 2D nanoflakes with average diameter of 50 – 200 nm and 0.2 - 1 μm. x-ray diffraction analysis suggest that protonated H2TTP-Fc aggregates exhibit amorphous nature, while H+[(Cl)ZnTTP-Fc]- revealed crystalline nature from layer-by-layer arrangement of nanoflakes assisted by π-π stacking and ion-dipole interactions. Hence, voltage responsive anion binding of metallo-porphyrins unique observation offer remarkable design of smart organic materials for sensors and biological applications.
关键词： anion binding,crystalline nanoflakes,metallo-porphyrin,self-assembly,bulk electrolysis
更新于2025-09-23 15:23:52
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Fate of protected HBT based chemodosimeters after undergoing deprotection: Restoration of ESIPT or generation of emissive phenoxide?
摘要： -OH protected 2-(hydroxyphenyl) benzothiazole (HBT) based ratiometric chemodosimeters have previously been reported to undergo regeneration of excited state intramolecular proton transfer (ESIPT) process upon deprotection. In the current work it is demonstrated for the first time that generation of anion of HBT leads to the optical changes in these types of chemodosimeters rather than regeneration of HBT by using a Hydrazine specific chemodosimeter based on substituted HBT.
关键词： chemodosimeter,anion,HBT,ESIPT,ratiometric
更新于2025-09-23 15:23:52
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Tris(N-methylferrocenyl-N-(2-phenylethyl)dithiocarbamato-S,S′)cobalt(III) for anion sensing and preparation of cobalt-iron sulfide nanoparticles: A new photocatalyst for the degradation of dyes
摘要： Tris(N-(pyrrol-2-ylmethyl)-N-butyldithiocarbamato-S,S')cobalt(III) (1) and tris(N-methylferrocenyl-N-(2-phenylethyl)dithiocarbamato-S,S')cobalt(III) (2) have been synthesized and characterized by elemental analysis and spectroscopy (IR, UV-vis and NMR). The elemental analysis and IR, 1H and 13C NMR spectra are consistent with the formation of the cobalt(III) complexes with dithiocarbamate ligands. The anion binding properties of 1 and 2 based on host-guest interaction have been examined with the use of cyclic voltammetry.This study showed that both complexes preferred to bind with I- compared to other halides. 2 has been used as precursors for the preparation of cobalt-iron sulfide nanoparticles. TEM image of cobalt-iron sulfide nanoparticles showed that the particles are spherical. The elemental compositions of the nanoparticles were confirmed by energy dispersive X-ray spectroscopy. IR spectral studies on nanoparticles confirm the presence of capping agent (triethylenetetramine). The nanoparticles were explored as photocatalysts to study the degradation of dyes using methylene blue and rhodamine-B in aqueous solution under UV irradiation. The cobalt-iron sulfide works as an efficient photocatalyst for degradation of rhodamine-B.
关键词： cobalt(III) dithiocarbamate,Anion sensing,single source precursors,nanoparticles,cobalt-iron sulfide
更新于2025-09-23 15:23:52
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In situ anion exchange strategy to construct flower-like BiOCl/BiOCOOH p-n heterojunctions for efficiently photocatalytic removal of aqueous toxic pollutants under solar irradiation
摘要： The poor charge separation of single-component semiconductor photocatalysts greatly restrains their practical application. Herein, we report an in situ anion-exchange strategy to controllably fabricate sunlight-driven p-n heterostructure photocatalyst BiOCl/BiOCOOH. In this synthetic process, the BiOCOOH microspheres not only act as the support to form heterostructures but also as Bi3+ supplier to generate BiOCl. Such an in situ anion-exchange route thus brought about the homogeneous distribution of BiOCl on the surface of BiOCOOH with tight interfacial contact. Under simulated solar illumination, the obtained BiOCl/BiOCOOH catalysts with p-n heterostructures show exceedingly superior photocatalytic activity against toxic pollutant (MO dye and TC antibiotic) to BiOCOOH and BiOCl. The optimal BiOCl/BiOCOOH, S3 sample has the highest photocatalytic activity with MO degradation rate constant of 0.0599 min?1, 2.9 or 9.7 folds higher than that of BiOCOOH or BiOCl. The alleviated charge separation and transfer as well as the flower-like structure mainly account for the enhanced performance. Radical scavenging experiments indicate that holes, ?OH and ?O2? collaboratively contribute to the degradation of pollutants. This work provides a novel sunlight-driven p-n heterojunction photocatalyst of BiOCl/BiOCOOH for wastewater treatment.
关键词： Anion exchange,Sunlight,BiOCl/BiOCOOH,Photocatalysis,p-n heterojunction
更新于2025-09-23 15:23:52
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Preparation of Anion Exchanger for High-Efficiency Purification of Halogen-substituted Hydrocarbon Solvents Used To Clean Metal Optics
摘要： Phenomenon of rising sorption capacity of AV-17-8 anion exchanger upon an increase in its humidity due to the superequivalent absorption of Cl– ions was revealed and substantiated. The puri? cation of halogen-substituted hydrocarbon solvents to remove acids under dynamic conditions by the ion-exchange method and the dynamics of sorption by anion exchangers of halogen-substituted solvents from model solutions were studied. It was shown that AV-17-8 anion exchanger is stable in halogen-substituted solvents and, when present in the OH– form, raises their stability against destruction, and the equilibrium sorption capacity of the anion exchanger is 2–3 times its exchange capacity.
关键词： cleaning,halogen-substituted hydrocarbon solvents,anion exchanger,resource,corrosion of the optical surface
更新于2025-09-23 15:23:52