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1.
Chaos ; 34(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38995988

RESUMO

Community structure plays a crucial role in realistic networks and different communities can be created by groups of interest and activity events, and exploring the impact of community properties on collective dynamics is an active topic in the field of network science. Here, we propose a new coupled model with different time scales for online social networks and offline epidemic spreading networks, in which community structure is added into online social networks to investigate its role in the interacting dynamics between information diffusion and epidemic spreading. We obtain the analytical equations of epidemic threshold by MMC (Microscopic Markov Chain) method and conduct a large quantities of numerical simulations using Monte Carlo simulations in order to verify the accuracy of the MMC method, and more valuable insights are also obtained. The results indicate that an increase in the probability of the mobility of an individual can delay the spread of epidemic-related information in the network, as well as delaying the time of the peak of the infection density in the network. However, an increase in the contact ability of mobile individuals produces a facilitating effect on the spread of epidemics. Finally, it is also found that the stronger the acceptance of an individual to information coming from a different community, the lower the infection density in the network, which suggests that it has an inhibitory effect on the disease spreading.


Assuntos
Epidemias , Humanos , Cadeias de Markov , Rede Social , Método de Monte Carlo , Simulação por Computador , Fatores de Tempo
2.
Small ; 19(24): e2208212, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36916691

RESUMO

137 Cs and 90 Sr are hazardous to ecological environment and human health due to their strong radioactivity, long half-life, and high mobility. However, effective adsorption and separation of Cs+ and Sr2+ from acidic radioactive wastewater is challenging due to stability issues of material and the strong competition of protons. Herein, a K+ -activated niobium germanate (K-NGH-1) presents efficient Cs+ /Sr2+ coadsorption and highly selective Cs+ /Sr2+ separation, respectively, under different acidity conditions. In neutral solution, K-NGH-1 exhibits ultrafast adsorption kinetics and high adsorption capacity for both Cs+ and Sr2+ (qm Cs  = 182.91 mg g-1 ; qm Sr  = 41.62 mg g-1 ). In 1 M HNO3 solution, K-NGH-1 still possesses qm Cs of 91.40 mg g-1 for Cs+ but almost no adsorption for Sr2+ . Moreover, K-NGH-1 can effectively separate Cs+ from 1 M HNO3 solutions with excess competing Sr2+ and Mn + (Mn +  = Na+ , Ca2+ , Mg2+ ) ions. Thus, efficient separation of Cs+ and Sr2+ is realized under acidic conditions. Besides, K-NGH-1 shows excellent acid and radiation resistance and recyclability. All the merits above endow K-NGH-1 with the first example of niobium germanates for radionuclides remediation. This work highlights the facile pH control approach towards bifunctional ion exchangers for efficient Cs+ /Sr2+ coadsorption and selective separation.

3.
Angew Chem Int Ed Engl ; 61(43): e202208875, 2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36043492

RESUMO

Ge-based hybrid perovskite materials have demonstrated great potential for second harmonic generation (SHG) due to the geometry and lone-pair induced non-centrosymmetric structures. Here, we report a new family of hybrid 3D Ge-based bromide perovskites AGeBr3 , A=CH3 NH3 (MA), CH(NH2 )2 (FA), Cs and FAGe0.5 Sn0.5 Br3 , crystallizing in polar space groups. These compounds exhibit tunable SHG responses, where MAGeBr3 shows the strongest SHG intensity (5×potassium dihydrogen phosphate, KDP). Structural and theoretical analysis indicate the high SHG efficiency is attributed to the displacement of Ge2+ along [111] direction and the relatively strong interactions between lone pair electrons of Ge2+ and polar MA cations along the c-axis. This work provides new structural insights for designing and fine-tuning the SHG properties in hybrid metal halide materials.

4.
Exp Eye Res ; 204: 108446, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33476605

RESUMO

Neovascular age-related macular degeneration (neoAMD) is the leading cause of blindness in AMD and manifests as choroidal neovascularization (CNV). Anti-vascular endothelial growth factor (VEGF) therapies are the mainstay treatments but with limited efficacy and cause detrimental effects on the retina after long-term application. These disadvantages warrant alternative strategy. Herein, we examined the effect on CNV by intravitreal injection of bortezomib, a reversible proteasome inhibitor, and further dissected the mechanism. Krypton red Laser was used to create CNV model in mice. The angiogenesis volume was assessed in choroidal flat-mount with isolectin GS-IB4 labeling and the leakage was examined with fluorescein fundus angiography. Injection of Borsub inhibited angiogenesis in the CNV model which was dose-dependent; the injection significantly inhibited leakage as well. Furthermore, Borsub injection reduced the contents of VEGF-A, macrophage chemotactic factor 1 (MCP-1), and platelet-derived growth factor (PDGF)-D but not PDGF-B, examined by enzyme-linked immunosorbent assay, in choroid/retinal pigment epithelium (RPE) tissue. These injections also reduced phospho-VEGFR-2 and phospho-PDGFRß in choroid/RPE tissue examined by immunoblotting. Moreover, Borsub inhibited the recruitment of mural cells or macrophages to laser-injured spots. Injection of Borsub indicated negative effect on scotopic and photopic responses recorded by electroretinogram. Altogether, intravitreal injection of Borsub significantly reduced CNV by antagonizing VEGF-A/Flk-1 and PDGF-D/PDGFRß pathways without impacting electroretinography parameters. Thus, Borsub may offer an invaluable therapy for the prevention and treatment of neoAMD.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Antineoplásicos/uso terapêutico , Bortezomib/uso terapêutico , Neovascularização de Coroide/tratamento farmacológico , Modelos Animais de Doenças , Linfocinas/antagonistas & inibidores , Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Western Blotting , Quimiocina CCL2/antagonistas & inibidores , Quimiocina CCL2/metabolismo , Neovascularização de Coroide/metabolismo , Neovascularização de Coroide/fisiopatologia , Reposicionamento de Medicamentos , Eletrorretinografia/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Angiofluoresceinografia , Marcação In Situ das Extremidades Cortadas , Injeções Intravítreas , Linfocinas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Confocal , Fator de Crescimento Derivado de Plaquetas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/metabolismo
5.
Inorg Chem ; 59(4): 2348-2357, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32017542

RESUMO

The directing effect of coordinating ligands in the formation of uranium molecular complexes has been well established, but the role of counterions in metal-ligand interactions remains ambiguous and requires further investigation. In this work, we describe the targeted isolation, through the choice of alkali-metal ions, of a family of tetravalent uranium sulfates, showing the influence of the overall topology and, unexpectedly, the UIV nuclearity upon the inclusion of such countercations. Analyses of the structures of uranium(IV) oxo/hydroxosulfate oligomeric species isolated from consistent synthetic conditions reveal that the incorporation of Na+ and Rb+ promotes the crystallization of 0D discrete clusters with a hexanuclear [U6O4(OH)4(H2O)4]12+ core, whereas the larger Cs+ ion allows for the isolation of a 2D-layered oligomer with a less condensed trinuclear [U3(O)]10+ center. This finding expands the prevalent view that counterions play an innocent role in molecular complex synthesis, affecting only the overall packing but not the local oligomerization. Interestingly, trends in nuclearity appear to correlate with the hydration enthalpies of alkali-metal cations, such that the alkali-metal cations with larger hydration enthalpies correspond to more hydrated complexes and cluster cores. These findings afford new insights into the mechanism of nucleation of UIV, and they also open a new path for the rational design and synthesis of targeted molecular complexes.

6.
Angew Chem Int Ed Engl ; 59(5): 1878-1883, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31742838

RESUMO

It is of vital importance to capture lanthanides (nuclear fission products) from waste solutions for radionuclide remediation owing to their hazards. The effective separation of lanthanides are achieved by an acid/base-stable and radiation-resistant vanadate, namely, [Me2 NH2 ]V3 O7 (1). It exhibits high adsorption capacities for lanthanides (qm Eu =161.4 mg g-1 ; qm Sm =139.2 mg g-1 ). And high adsorption capacities are maintained over a pH range of 2.0-6.9 (qm Eu =75.1 mg g-1 at low pH of 2.5). It displays high selectivity for Eu3+ (simulant of An3+ ) against a large excess of interfering ions. It can efficiently separate Eu3+ and Cs+ (or Sr2+ ) with the highest separation factor SFEu/Cs of 156 (SFEu/Sr of 134) to date. The adsorption mechanism is revealed by calculations and XPS, EXAFS, Raman, and elemental analyses. These merits combined with facile synthesis and convenient elution makes the title vanadate a promising lanthanide scavenger for environmental remediation.

7.
Inorg Chem ; 58(7): 4103-4109, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30929449

RESUMO

Highly efficient and effective removal of mercury from water, especially at very low ionic concentration, remains a grand challenge for ecosystem protection and human health. Herein, we present the synthesis, crystal structure, and mercury uptake performance of a new heterometallic chalcogenidometalate, namely, [TAEAH][TAEAH2]0.6Ga2.2Sn1.8S8·H2O (GaSnS-1; TAEA = Tris(2-aminoethyl)amine). GaSnS-1 features a three-dimensional (3D) zeolite-typed (RWY) framework structure of [Ga2.2Sn1.8S8] n2.2 n- that is constructed by corner-sharing of supertetrahedral [Ga2.2Sn1.8S10]6.2- T2 clusters. The equilibrium model study indicated that the maximum Hg2+ saturation capacity of GaSnS-1 was 213.9 mg/g. GaSnS-1 possessed extremely rapid adsorption kinetics following the pseudo-second-order model with a k2 of 5.65 × 102 g·mg-1·min-1. Particularly, GaSnS-1 exhibited excellent selectivity for Hg2+ ions with a high distribution coefficient Kd value of 1.62 × 107 mL/g and high removal efficiency of close to 100%. The superior Hg2+ ion adsorption performance was also impressive despite the presence of excessive competing cations and the acidic/basic conditions. Furthermore, a simple chromatographic column loaded with GaSnS-1 microcrystals is capable of rapidly and effectively capturing Hg2+ ions far below the upper limit (2 ppb, USA-EPA) of drinking water. These advantages of GaSnS-1 make it a promising candidate for the fast and efficient remediation of Hg2+-contaminated water sources.

8.
Inorg Chem ; 58(17): 11622-11629, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31411464

RESUMO

For the nuclear industry, uranium is not only an important strategic resource but also a serious global contaminant with radiotoxicity and high chemotoxicity. It is very important to efficiently capture uranium from complex aqueous solutions for further treatment and disposal of nuclear wastes. Herein, we first demonstrate the suitability of a three-dimensional (3D) water-stable K+-exchanged zeolitic sulfide, namely K@GaSnS-1, for the remediation of radioactive and toxic uranium by ion exchange. In comparison to the pristine compound GaSnS-1, the K+-activated porous sulfide K@GaSnS-1 exhibits faster [UO2]2+ ion uptake kinetics, following the pseudo-second-order adsorption model. Further studies indicate that K@GaSnS-1 shows high exchange capacity (qmU = 147.6 mg/g) and wide pH resistance (pH 2.75-10.87). In particular, it can efficiently capture [UO2]2+ ion even when excessive amounts of Na+, K+, Mg2+, and Ca2+ ions are present. The highest distribution coefficient value Kd, signifying the affinity and selectivity for [UO2]2+ ion, reaches as high as 1.24 × 104 mL/g. More importantly, the uranium in corresponding exchanged samples can be facilely and effectively eluted by a low-cost and eco-friendly method. These merits of K@GaSnS-1 make it promising for the effective and selective removal of uranium from complex contaminated water.

9.
BMC Anesthesiol ; 19(1): 131, 2019 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-31324142

RESUMO

BACKGROUND: Dexmedetomidine (DEX) has been used as an anesthetic for decades. The present investigation aimed to elucidate the analgesic impact of DEX on 2,4,6-Trinitrobenzenesulfonic acid (TNBS)-induced chronic inflammatory visceral pain (CIVP) in rats. METHODS: TNBS with or without DEX to Male Sprague-Dawley SD rats were randomly divided into four groups: normal, CIVP, DEX, and vehicle. Pain behaviors were assessed and the abdominal withdrawal reflex, mechanical withdrawal threshold, and thermal withdrawal latency were recorded. Quantitative polymerase chain reaction data showed increased expressions of pro-inflammatory cytokines (IL-6, IL-1ß and TNF-α) in the spinal cord tissues of rats. RESULTS: RNA microarray and quantitative polymerase chain reaction results indicated that miR-34a was downregulated by TNBS induction, but it was upregulated by DEX administration. Further studies showed that transfection of adenovirus-miR-34a inhibitor reversed the effect of DEX on the pain behaviors and spinal-cord pro-inflammatory-cytokine generation in CIVP rats. Additionally, we found that miR-34a targeted the 3'-UTR of the HDAC2 gene, as evinced by the increased HDAC2 expression in the CIVP and DEX + miR-34a inhibitor groups, and decreased HDAC2 signaling in the DEX group. Moreover, knock-down of HDAC2 restored DEX-attenuated pain behaviors and reduced pro-inflammatory cytokine production. CONCLUSIONS: DEX thus exhibited an analgesic effect on CIVP rats through the miR-34a-mediated HDAC2 pathway and suppressed visceral hypersensitivity.


Assuntos
Dexmedetomidina/farmacologia , Histona Desacetilase 2/metabolismo , MicroRNAs/metabolismo , Dor Visceral/terapia , Regiões 3' não Traduzidas , Animais , Dor Crônica/terapia , Citocinas/metabolismo , Regulação para Baixo , Histona Desacetilase 2/genética , Hipnóticos e Sedativos/farmacologia , Masculino , Análise em Microsséries , Limiar da Dor , Reação em Cadeia da Polimerase , Distribuição Aleatória , Ratos Sprague-Dawley , Reflexo , Medula Espinal/metabolismo , Ácido Trinitrobenzenossulfônico/efeitos adversos , Regulação para Cima , Dor Visceral/induzido quimicamente
10.
J Environ Manage ; 249: 109427, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31450198

RESUMO

Industrialization and accelerated population growth have created a huge amount of sewage sludge. Many studies have reported the sewage sludge as a sink of major and trace elements, but less is known about their geochemical fractionations. In order to assess the mobility, the distribution, bioavailability, and toxicity of those elements in sludge, we collected the sewage sludge samples from all the seven wastewater treatment plants in Xiamen City, China. Results revealed a strong spatial variation and the occurrence of 48 elements with concentrations ranging from 1.00×10-2 mg kg-1 (Re) to 9.03×101 g kg-1 (Fe) on the basis of dry sludge weight. Sequential extraction procedure showed that residual and oxidizable fractions were the main geochemical fractions of most studied elements. However, Ca, Mn, Sr, and Ni were mainly bound to acid-exchangeable fractions, while Fe, Zn, Cd, Cr, Co, and V were mainly distributed in the reducible fractions. The contamination factor and risk assessment code indicated that Ni, Cu, Zn, Cd, Cr, Co, Sr, Ca, Mn, Mo, Re, and W were highly mobile with less retention time and exerted high environmental risks through sludge land application. The sludge disposal strategy should consider not only the total concentrations of a broad range of elements but also their bioavailability.


Assuntos
Metais Pesados , Oligoelementos , China , Cidades , Medição de Risco , Esgotos , Eliminação de Resíduos Líquidos
11.
J Am Chem Soc ; 140(35): 11133-11140, 2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-30088768

RESUMO

Unconventional ion exchangers can achieve efficient removal of [UO2]2+, Cs+, and Sr2+ ions from complex aqueous solutions and are of great interest for environmental remediation. We report two new gallium thioantimonates, [Me2NH2]2[Ga2Sb2S7]·H2O (FJSM-GAS-1) and [Et2NH2]2[Ga2Sb2S7]·H2O (FJSM-GAS-2), which present excellent ion exchange properties for [UO2]2+, Cs+, and Sr2+ ions. They exhibit high ion exchange capacities for [UO2]2+, Cs+, and Sr2+ ions ( qmU = 196 mg/g, qmCs = 164 mg/g, and qmSr = 80 mg/g for FJSM-GAS-1, qmU = 144 mg/g for FJSM-GAS-2) and short equilibrium times for [UO2]2+ ion exchange (5 min for FJSM-GAS-1 and 15 min for FJSM-GAS-2, respectively). Both compounds display active ion exchange with [UO2]2+ in the pH range of 2.9-10.5. Moreover, the sulfide compounds could maintain high distribution coefficients KdU even in the presence of excess Na+, Ca2+, and HCO3-. The distribution coefficient KdU of 6.06 × 106 mL/g exhibited by FJSM-GAS-1 is the highest among the reported U adsorbents. The [UO2]2+-laden products can be recycled by conveniently eluting the uranium with a low-cost method. These advantages combined with facile synthesis, as well as ß and γ radiation resistance, make FJSM-GAS-1 and FJSM-GAS-2 promising for selective separations in nuclear waste remediation.

12.
J Am Chem Soc ; 139(12): 4314-4317, 2017 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-28260379

RESUMO

Exploring new ion-exchangers for the recovery of rare earth elements (REEs) and recycling is worthwhile for the high-tech industry and an eco-friendly sustainable economy. The efficient enrichment of low concentration REE from complex aqueous solutions containing large excess of competitive ions is challenging. Here we present a chalcogenide example as a superior REE ion-exchanger efficiently removing them from very complex aqueous solutions, (Me2NH2)1.33(Me3NH)0.67 Sn3S7·1.25H2O (FJSM-SnS). The material exhibits fast and efficient ion exchange behavior with short equilibrium time (<5 min), high adsorption capacity (139 mg/g for Eu, 147 mg/g for Tb, 126 mg/g for Nd), wide pH resistance (1.9-8.5), the largest distribution coefficient (Kd) value of 6.5 × 106 mL/g, good selectivity against Al3+, Fe3+, and Na+ ions, and high recovery rate (>99%) at low concentrations. Moreover, after ion-exchange, the REE in corresponding exchanged products could be easily recovered by elution. FJSM-SnS has superior capacity and faster absorption kinetics than other states of the artificial REE sorbents such as Al2O3/EG, clay minerals, zeolite, and activated carbon.

13.
J Am Chem Soc ; 138(38): 12578-85, 2016 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-27584863

RESUMO

Uranium is important in the nuclear fuel cycle both as an energy source and as radioactive waste. It is of vital importance to recover uranium from nuclear waste solutions for further treatment and disposal. Herein we present the first chalcogenide example, (Me2NH2)1.33(Me3NH)0.67Sn3S7·1.25H2O (FJSM-SnS), in which organic amine cations can be used for selective UO2(2+) ion-exchange. The UO2(2+)-exchange kinetics perfectly conforms to pseudo-second-order reaction, which is observed for the first time in a chalcogenide ion-exchanger. This reveals the chemical adsorption process and its ion-exchange mechanism. FJSM-SnS has excellent pH stability in both strongly acidic and basic environments (pH = 2.1-11), with a maximum uranium-exchange capacity of 338.43 mg/g. It can efficiently capture UO2(2+) ions in the presence of high concentrations of Na(+), Ca(2+), or HCO3(-) (the highest distribution coefficient Kd value reached 4.28 × 10(4) mL/g). The material is also very effective in removing of trace levels of U in the presence of excess Na(+) (the relative amounts of U removed are close to 100%). The UO2(2+)···S(2-) interactions are the basis for the high selectivity. Importantly, the uranyl ion in the exchanged products could be easily eluted with an environmentally friendly method, by treating the UO2(2+)-laden materials with a concentrated KCl solution. These advantages coupled with the very high loading capacity, low cost, environmentally friendly nature, and facile synthesis make FJSM-SnS a new promising remediation material for removal of radioactive U from nuclear waste solutions.

14.
J Neurochem ; 136(1): 186-93, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26485193

RESUMO

Convincing data demonstrate that D-serine, a racemized product of serine racemase (SR), contributes to neurotoxicity. Furthermore, a line of evidence suggests that SR/D-serine contributes to retinal neurodegeneration in a diabetic retinopathy rat model and diabetic retinopathy patients. However, the connection between SR/D-serine and retinal neurodegeneration remains unclear. Herein, we report that intravitreal injection of N-methyl-D-aspartate (NMDA) induces excitotoxicity in rodent retina; this retinal neurodegeneration was attenuated in retina carrying a loss-of-function of mutation in Srr, the gene for SR, termed Srr(ochre269). Under the condition of NMDA injection, either posterior pole or middle - but not peripheral - retina from Srr(ochre269) mice was found to retain more retinal ganglion cells (RGC) than the counterpart from w/t (RGCs were identified with retrograde labeling). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining further demonstrated reduced RGC apoptosis from Srr(ochre269) compared to w/t mice under the condition of NMDA injection. Collectively, our studies demonstrate a pivotal role of SR/D-serine in retinal neurotoxicity. We demonstrated that loss-of-function mutation of the gene encoding serine racemase significantly attenuates excitotoxicity in retina; excitotoxicity accounts for retinal ganglion cell (RGC) demise in diabetic retinopathy (DR). We think that our findings deepen the current knowledge of the mechanisms of RGC degeneration.


Assuntos
Agonistas de Aminoácidos Excitatórios/toxicidade , Mutação/genética , N-Metilaspartato/toxicidade , Racemases e Epimerases/genética , Células Ganglionares da Retina/efeitos dos fármacos , Células Ganglionares da Retina/enzimologia , Animais , Agonistas de Aminoácidos Excitatórios/administração & dosagem , Feminino , Injeções Intravítreas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , N-Metilaspartato/administração & dosagem , Retina/efeitos dos fármacos , Retina/enzimologia
15.
Chem Rec ; 16(2): 582-600, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26809360

RESUMO

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.

16.
Inorg Chem ; 55(21): 10855-10858, 2016 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-27768295

RESUMO

An open-framework chalcogenidostannate, namely, [CH3NH3]2Ag4SnIV2SnIIS8 (1), has been solvothermally synthesized and structurally characterized, which represents the first organically templated three-dimensional (3D) Ag-Sn-S compound containing the mixed valence of Sn(IV)/Sn(II) and displays visible-light-driven photocatalytic activity for degradation of crystal violet (CV).

17.
Inorg Chem ; 55(11): 5110-2, 2016 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-27228165

RESUMO

A new chalcogenide crystal, (NH4)4Ag12Sn7Se22 (FJSM-STS), has been solvothermally synthesized. The crystal structure, which is composed of arrays of [Sn3Se9]n(6n-) chains interconnecting [SnAg6Se10]n(10n-) and [Ag3Se4]n(5n-) layers, is unprecedented among the reported A/Ag/Sn/Q (A = cation; Q = S, Se, and Te) compounds. Optical absorption together with theoretical calculations of the band structure indicate a direct band gap of 1.21 eV for FJSM-STS, which is close to the ideal band gap to maximize the photoconversion efficiency proposed by Shockley and Queisser. The toxic-metal-free crystal of FJSM-STS exhibits obvious photosensitivity in the near-infrared range. The variates of power and temperature on the photosensitivity have been studied.

18.
Inorg Chem ; 54(17): 8474-81, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26291119

RESUMO

Among numerous heterometallic chalcogenidoantimonates, relatively a few amine-directed Ge-Sb-S compounds have been synthesized. Presented here are the solvothermal syntheses, crystal structures, and ion-exchange, optical, and photocatalytic properties of two novel amine-directed Ge-Sb-S compounds, namely, [CH3NH3]20Ge10Sb28S72·7H2O (1) and [(CH3CH2CH2)2NH2]3Ge3Sb5S15·0.5(C2H5OH) (2). The structure of 1 features an unprecedented two-dimensional Ge-Sb-S double-layer composed of two twofold rotational symmetry-related thick [Ge8Sb28S72]n(28n-) single layers adhered via vertex-sharing [GeS4] tetrahedra. Compound 2 features a unique [Ge3Sb5S15]n(3n-) slab perforated with large elliptic-like windows. Remarkably, compound 1 exhibited excellent Cs(+) ion-exchange property despite the presence of excess competitive cations, such as Na(+), K(+), Mg(2+), and Ca(2+) ions. In addition, compound 1 displayed visible-light-driven photocatalytic activity for degradation of rhodamine B.

19.
Dalton Trans ; 53(5): 2318-2323, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38205611

RESUMO

Three new group IIIA metal phosphate-oxalate (MPO) compounds, namely [(CH3)2NH2]2[M2(HPO4)2(H2PO4)2(C2O4)] (M = Al (1), Ga (2)) and [(CH3)2NH2]2[In2(HPO4)2(H2PO4)2(C2O4)]·H2O (3), have been synthesized. Their crystal structures feature an anionic layer with the sql topology net. In particular, 1 displays a proton conductivity (σ) of 9.09 × 10-3 S cm-1 at 85 °C and under 98% relative humidity, which is the highest among MPOs. This study not only endows the main group metal-based MPO family with new members, but also contributes to further understanding of the structure-directing roles of amines and provides a feasible idea for improving the proton conductivity of MPOs.

20.
Dalton Trans ; 53(13): 6063-6069, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38477327

RESUMO

A new layered metal sulfide, namely (C6H15N3)1.3(NH4)1.5H1.5In3SnS8 (1, C6H15N3 = N-(2-aminoethyl) piperazine), has been solvothermally synthesized and characterized. Compound 1 crystallizes in the monoclinic space group C2/c. Its structure features a two-dimensional layer of {In3SnS8}n3n- with the (4,4) topology net, which is formed by interlinking supertetrahedral T2 clusters as secondary building units. Band structure calculations revealed that 1 had a band gap of 2.7 eV. The photoelectric response of 1 showed steady and reversible on/off cycles with an "on" state of 121.13 nA cm-2. Moreover, the activation of 1 by replacing the sluggish organic cations with harder K+ ions endowed the material with improved adsorption performances for Sr2+ ions from aqueous solutions.

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