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1.
Inorg Chem ; 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32410454

RESUMO

Good aqueous dispersibility of metal chalcogenide nanoclusters with an atomically precise structure is desirable to achieve tiny and uniform cluster-based "quantum dots". However, there are big challenges toward this goal, especially for the large-sized nanoclusters without covalently bonded organic ligands, because the strong electrostatic interactions between closely packed negatively charged nanoclusters and protonated organic amine templates in the crystal lattice impede the dispersion of cluster-based bulk crystalline samples. Here, we report two iso-structured crystalline metal chalcogenides composed of discrete supertetrahedral T4-MInS nanoclusters with the formulas of [M4In16S35]14- (denoted ISC-16-MInS, M = Zn and Fe), which adopt a sodalite-net loose-packing pattern in the crystal lattice and display superior dispersibility in water and some organic solvents as compared to other cases composed of the same type of nanoclusters with close-packing pattern. The dispersed T4-MInS nanoclusters were unexpectedly stabilized by adsorbing a certain number of H+ ions on surface S sites and simultaneously dropping partial surface S2- ions, instead of being surrounded by protonated organic amines, which was clearly verified by electrospray ionization mass spectrometry analysis. Notably, ISC-16-ZnInS behaves with superior performance on photodegradation of rhodamine B dye to ISC-16-FeInS. This is attributed to their difference in divalent-metal-directed separation efficiency of the photogenerated electrons and holes. This work holds great promise for the potential functional applications of uniformly dispersed semiconductor nanoclusters, such as cluster-based thin film devices, photoelectrodes, and photocatalysis.

2.
J Am Chem Soc ; 142(14): 6649-6660, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32176486

RESUMO

Strong Mn-Mn coupling interactions (dipole-dipole and spin-exchange), predominantly determined by statistically and apparently short Mn···Mn distances in traditional heavily Mn2+-doped semiconductors, can promote energy transfer within randomly positioned and close-knit Mn2+ pairs. However, the intrinsic mechanism on controlling Mn2+ emission efficiency is still elusive due to the lack of precise structure information on local tetrahedrally coordinated Mn2+ ions. Herein, a group of Mn2+-containing metal-chalcogenide open frameworks (MCOFs), built from [Mn4In16S35] nanoclusters (denoted T4-MnInS) with a precise [Mn4S] configuration and length-variable linkers, were prepared and selected as unique models to address the above-mentioned issues. MCOF-5 and MCOF-6 that contained a symmetrical [Mn4S] core with a D2d point group and relatively long Mn···Mn distance (∼3.9645 Å) exhibited obvious red emission, while no room-temperature PL emission was observed in MCOF-7 that contained an asymmetric [Mn4S] configuration with a C1 point group and relatively short Mn···Mn distance (∼3.9204 Å). The differences of Mn-Mn dipole-dipole and spin-exchange interactions were verified through transient photoluminescent spectroscopy, electron spin resonance (ESR), and magnetic measurements. Compared to MCOF-5 and MCOF-6 showing a narrower/stronger ESR signal and longer decay lifetime of microseconds, MCOF-7 displayed a much broader/weaker ESR signal and shorter decay lifetime of nanoseconds. The results demonstrated the dominant role of distance-directed Mn-Mn dipole-dipole interactions over symmetry-directed spin-exchange interactions in modulating PL quenching behavior of Mn2+ emission. More importantly, the reported work offers a new pathway to elucidate Mn2+-site-dependent photoluminescence regulation mechanism from the perspective of atomically precise nanoclusters.

3.
Nanoscale ; 12(2): 772-784, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31830183

RESUMO

The direct electroreduction of CO2 to ratio-tunable syngas (CO + H2) is an appealing solution to provide important feedstocks for many industrial processes. However, low-cost, Earth-abundant yet efficient and stable electrocatalysts for composition-adjustable syngas have still not been realized for practical applications. Herein, new hierarchical 0D/2D heterostructures of SnO2 nanoparticles (NPs) confined on CuS nanosheets (NSs) were designed to enable CO2 electroreduction to a wide-range syngas (CO/H2: 0.11-3.86) with high faradaic efficiency (>85%), remarkable turnover frequency (96.12 h-1) and excellent durability (over 24 h). Detailed experimental characterization studies together with theoretical calculations manifest that the ascendant catalytic performance is not only attributed to the heterostructure of ultrasmall SnO2 NPs homogeneously confined on ultrathin CuS NSs, which endows the maximum exposure of active sites and faster charge transfer, but is also accounted by the strong interaction between well-defined SnO2 and CuS interfaces, which modulated reaction free-energies of reaction intermediates and hence improved the activity of CO2 electroreduction to highly ratio-tunable syngas. This work provides a better understanding and a new strategy for intermediate regulation by interface engineering of hereostructures for CO2 reduction and beyond.

4.
Inorg Chem ; 58(18): 12415-12421, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31483642

RESUMO

Many strategies to optimize molybdenum selenide based electrocatalysts for hydrogen evolution reaction (HER) have been explored; however, the modulation of molybdenum selenide on the molecular scale remains an ongoing challenge. Here, we synthesized a new molecular HER electrocatalyst based on a molybdenum-selenium cluster (Mo3Se13) and further realized its modulation by precise sulfur substitution at the molecular level to enhance the HER activity. The density functional theory (DFT) calculations demonstrated that the substituted sulfur could promote the hydrogen adsorption process and thus improve the HER performance. This work not only realizes the selective replacement of the bridging selenium atom with a sulfur atom in the molybdenum-selenium cluster for the first time but also provides a precise model for illustrating the structure-property relationship in electrocatalysis on the molecular level.

5.
Dalton Trans ; 48(29): 10799-10803, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31263815

RESUMO

Enlarging the openess of chalcogenide frameworks is of significance for functionalizing semiconducting open frameworks, which are usually limited by their own interpenetration due to the rigid clusters and monotonous linkers. Herein, we report two zeolite-like chalcogenide open frameworks constructed from unusual defective supertetrahedral clusters and various kinds of linkers. Both the structures exhibit impressive architecture and high extra-framework volume ratios.

6.
Chem Commun (Camb) ; 55(56): 8146-8149, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31240283

RESUMO

Herein, we report a simple, yet highly effective approach for constructing a new type of sub-nanoscale ZnS/ZnO heterojunction (∼2-4 nm) with highly rich interfaces by photoetching hybrid Zn-S-O molecular clusters. The obtained ZnS/ZnO heterojunctions with ZnS spheres decorated with ultrasmall amorphous ZnO dots exhibit superior photocatalytic performance (∼94.0 µmol g-1 h-1), compared to nanoscale homologous samples obtained via conventional heat treatment (∼17.0-21.4 µmol g-1 h-1). Such a light-triggered molecular-cluster-to-heterojunction strategy provides a synthetic approach to building other sub-nanoscale hetero-structured materials for further promoting the catalytic-related applications.

7.
Dalton Trans ; 48(22): 7537-7540, 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31066399

RESUMO

Reported here are three new metal chalcogenide open frameworks built from supertetrahedral [In35S52O8] (denoted as T5-InOS or o-T5) and [In10S20] (denoted as T3-InS) nanoclusters of different sizes and compositions via co-assembly and/or hybrid assembly modes. Such a set of cluster-based superlattices with dia topological structures clearly exhibit quantum size effects and electronic coupling interaction of adjacent nanoclusters, which can effectively explain that the band gap of the T3-(o-T5) hybrid-assembled material lies in the middle of T3-T3 and (o-T5)-(o-T5) co-assembled materials.

8.
Inorg Chem ; 58(6): 3582-3585, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30793596

RESUMO

High-degree connectivity of clusters in open-framework chalcogenide semiconductors conceptually facilitates electron mobility between clusters; however, no direct evidence was obtained to prove the prediction because of the shortage of suitable structure models among such systems. Herein, two open-framework chalcogenides built from the same types of heterometallic P2-CuInSnS clusters but with different spatial connectivities of clusters were obtained, in which 3-connected clusters are assembled into a 3D framework with SrSi2 topology (MCOF-1) and 4-connected clusters (µ4-P2) are arranged into diamond topology (MCOF-2). Compared to MCOF-1, MCOF-2 exhibits a relatively rapid photocurrent response, good reproducibility, and high electrocatalytic oxygen reduction reaction activity. This work substantially demonstrates that cluster-based chalcogenide frameworks with higher-degree cluster connectivity possess faster electron-transport efficiency between adjacent clusters relative to low-connected ones with the same building units.

9.
Inorg Chem ; 58(1): 31-34, 2019 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-30550271

RESUMO

Reported here are two novel metal chalcogenide superlattices built from unusual supertetrahedral TO2-InSnS clusters. With regard to only one previously reported case of a TO2-InS-based 2D-layered structure, such a combination of In-Sn-S components is thought to be reasonable for leading to the first observation of 3D superlattices based on TO2-InSnS clusters. Besides, these title semiconducting materials also display good performance on the electrocatalytic oxygen reduction reaction.

10.
Chem Commun (Camb) ; 54(80): 11272-11275, 2018 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-30232471

RESUMO

We demonstrated here a novel semiconducting metal-chalcogenide-organic framework (MCOF-89) with an optical bandgap through the unlikely assembly between a metal chalcogenide unit and carboxylic acid. The elusive metal-chalcogenide unit [Mn4(µ4-S)] with square-planar tetra-coordinated sulfur (sptS) is for the first time observed in MOFs.

11.
Inorg Chem ; 57(16): 9790-9793, 2018 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-30074779

RESUMO

Constructing a hybrid connection mode between cluster-based building blocks is of particular importance in the pursuit of fascinating framework structures. Reported here are two new metal chalcogenide imidazolate frameworks (SCIF-11 and SCIF-12) with a hybrid intercluster bridging mode and a unique interrupted topological structure. SCIF-11 has a typical dia topology with a T3-InS supertetrahedral cluster as the node and an imidazolate (IM) ligand as the linker, but it for the first time combines two kinds of intercluster connecting modes: T3-S-T3 and T3-IM-T3. Interestingly, SCIF-12 composed of T4-CdInS supertetrahedral clusters and IM ligands possesses a unique 3,4-connected interrupted framework with ins topology, with this being the first case in the family of cluster-based metal chalcogenide frameworks. This work provides a new strategy on enriching the intercluster bridging modes and topological types of metal chalcogenide frameworks.

12.
Inorg Chem ; 57(17): 10485-10488, 2018 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-30118223

RESUMO

A new family member of T p, q-based hierarchical chalcogenide architecture was created by assembling regular T4-ZnInS clusters into a periodically "hollowed-out" cubic ZnS-type structure framework (T4,∞) via the cross-linker of the tetracoordinated corner µ4-S2-. Ion-exchange and CO2 adsorption experiments suggest that such a structure with a corner µ4-S2- linker has structural stability superior to those of previously reported chalcogenide open frameworks composed of the same T4-ZnInS clusters with a bicoordinated (µ2-S2-) or a tricoordinated (µ3-S2-) cross-linker. Importantly, this case further demonstrates the feasibility of systematically engineering stable porous crystalline chalcogenide frameworks by a "hollow-out" strategy.

13.
Inorg Chem ; 57(11): 6710-6715, 2018 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-29792414

RESUMO

Reported here is a unique crystalline semiconductor open-framework material built from the large-sized supertetrahedral T4 and T5 clusters with the Mn-In-S compositions. The hybrid assembly between T4 and T5 clusters by sharing terminal µ2-S2- is for the first time observed among the cluster-based chalcogenide open frameworks. Such three-dimensional structure displays non-interpenetrated diamond-type topology with extra-large nonframework volume of 82%. Moreover, ion exchange, CO2 adsorption, as well as photoluminescence properties of the title compound are also investigated.

14.
Inorg Chem ; 57(8): 4248-4251, 2018 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-29611702

RESUMO

Unexpected nonlinear variation in the composition and optical band gap was observed in an alloyed open-framework metal chalcogenide composed of supertetrahedral clusters. A tentative hypothesis was proposed to explain how the title compound [In28Se54(H2O)4]·24H+-PR· nH2O (PR = piperidine) exhibits a limitation in the S-alloying level and a large variation in the optical band gap.

15.
ACS Appl Mater Interfaces ; 10(16): 13413-13424, 2018 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-29613757

RESUMO

The highly efficient and cheap non-Pt-based electrocatalysts such as transition-based catalysts prepared via facile methods for oxygen reduction reaction (ORR) are desirable for large-scale practical industry applications in energy conversion and storage systems. Herein, we report a straightforward top-down synthesis of monodisperse ultrasmall manganese-doped multimetallic (ZnGe) oxysulfide nanoparticles (NPs) as an efficient ORR electrocatalyst by simple ultrasonic treatment of the Mn-doped Zn-Ge-S chalcogenidometalate crystal precursors in H2O/EtOH for only 1 h at room temperature. Thus obtained ultrasmall monodisperse Mn-doped oxysulfide NPs with ultralow Mn loading level (3.92 wt %) not only exhibit comparable onset and half-wave potential (0.92 and 0.86 V vs reversible hydrogen electrode, respectively) to the commercial 20 wt % Pt/C but also exceptionally high metal mass activity (189 mA/mg at 0.8 V) and good methanol tolerance. A combination of transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical analysis demonstrated that the homogenous distribution of a large amount of Mn(III) on the surface of NPs mainly accounts for the high ORR activity. We believe that this simple synthesis of Mn-doped multimetallic (ZnGe) oxysulfide NPs derived from chalcogenidometalates will open a new route to explore the utilization of discrete-cluster-based chalcogenidometalates as novel non-Pt electrocatalysts for energy applications and provide a facile way to realize the effective reduction of the amount of catalyst while keeping desired catalytic performances.

16.
Dalton Trans ; 47(10): 3227-3230, 2018 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-29423493

RESUMO

Herein we report a new 3D neutral chalcogenide framework constructed by using a supertetrahedral T3 cluster ([Mn2Ga4Sn4S20]) as the building unit and a metal complex ([Mn(dach)2], dach = 1,2-diaminocyclohexane) as the linker. Significantly, the obtained material exhibits high-efficiency electrocatalytic oxygen reduction activity with quasi-four-electron transfer and a small Tafel slope, much better than that of commercial Pt/C (10 wt%).

17.
Inorg Chem ; 57(3): 921-925, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29308887

RESUMO

Reported here is a new metal chalcogenide semiconductor with the double-interpenetrated zeolitic nabesite framework, which is constructed by the rare extended spiro-5 units with supertetrahedral clusters serving as building units. Different from the TO4-based simple spiro-5 unit frequently observed in oxide-based zeolites, the extended spiro-5 unit composed of five supertetrahedral T3-InSnS clusters is for the first time observed in the family of open-framework metal chalcogenides. Such secondary building units finally assemble into a rare NAB topological framework with large external space. In addition, the title semiconductor material also displays good properties in photocurrent response and electrocatalytic oxygen reduction reaction.

18.
Inorg Chem ; 56(24): 14763-14766, 2017 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-29199823

RESUMO

Developing the structural diversity of microporous zeolitic frameworks with integrated semiconducting properties is promising but remains a challenge. Reported here are two unique crystalline semiconductor zeolite analogues constructed from two kinds of indium selenide clusters with augmented ctn and zeolite-type sod networks. The intrinsic semiconducting nature in these In-Se domains gives rise to pore-size-dependent and visible-light-driven photocatalytic activity for organic dye degradation.

19.
Dalton Trans ; 47(1): 49-52, 2017 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-29182176

RESUMO

Reported here is a unique non-interpenetrated open-framework metal chalcogenide built on a supertetrahedral [Fe4In16S35]14- cluster. The non-interpenetrated feature accompanied with the relatively large-sized cluster leads to a high extra-framework volume.

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