Discrete Supertetrahedral T5 Selenide Clusters and Their Se/S Solid Solutions: Ionic‐Liquid‐Assisted Precursor Route Syntheses and Photocatalytic Properties

Abstract

Although supertetrahedralT n sulfide clusters (n = 2-6) have been extensively explored, the synthesis of Tn selenide clusters with n > 4h as not been achieved thus far.R eported here are ionic-liquid (IL)-assisted precursor route syntheses, characterizations, and the photocatalytic properties of six new M-In-Q (M = Cu or Cd;Q= Se or Se/S) chalcogenide compounds,n amely [Bmmim] 12 MIm = 1-methylimidazole), and [Bmmim] 9 Cd 6 In 28 Se 8 S 44 Cl(MIm) 3 (T5-6). The cluster compounds T5-1 and T5-3 represent the largest molecular supertetrahedralT n selenide clusters to date. Under visiblelight illumination,t he Cu-In-Q compounds showed photoca-talytic activity towards the decompositiono fc rystal violet, whereas the Cd-In-Q compounds exhibited good photocatalytic H 2 evolution activity.I nterestingly,t he experimental results show that the photocatalytic performances of the selenide/sulfide solid solutions weres ignificantly bettert han those of their selenide analogues, for example, the degradation time of the organic dye with T5-2 wasm uch shorter than that with T5-1,w hereas the photocatalytic H 2 evolution efficiencies with T5-3-T5-6 improved significantly with increasings ulfur content.T his work highlightst he significance of IL-assisted precursor route synthesis and the tuning of photocatalytic properties through the formation of solids olutions.Scheme1.Typical crystallization processes of the cluster compounds T5-1-T5-6 in the IL [Bmmim]Cl. The amounts of reactantsare given in mmoles.

Discrete Supertetrahedral Tn Chalcogenido Clusters Synthesized in Ionic Liquids: Crystal Structures and Photocatalytic Activity

“…Recently, photodegradation of CV under visible light illumination for discrete clusters T5-9 and T5-10 was investigated by our group. [52] As shown in Figures 10a and 10 9). After illumination for 80 min, nearly 99 % of CV was degraded under the photocatalysis of T5-10, whereas it took about 120 min for T5-9 to degrade about 93 % of CV.…”

“…A = Li, Na or K, x = 4, 13 or 14) in ILs with or without other chalcogen source and auxiliary solvents; [45,47,[49][50] (3) preparing monometallic gel-like precursors such as InÀ QÀ ILs (Q = chalcogen elements) precursor in ILs and then reacting it with another metal salt in molecular solvents; [48,[51][52] (4) preparing bimetallic gel-like precursors such as CuÀ InÀ SeÀ IL precursor in ILs and crystallization (with chalcogen source) in auxiliary solvents. [52] In abovementioned routes, the microwave-assisted method had been widely adopted to obtain the gel-like precursors that were essential to obtain desired Tn clusters in some reactions. For instance, the InÀ SeÀ IL precursor was crucial to the crystallization of T3-5, while it could not be obtained by simply combining the same reactants without using the precursor.…”

“…The (T5-14). [52] In T5-9 (Figure 6a), the central tetrahedral metal site is assigned to Cu + ion coordinated with four Se, and the other four Cu + ions are distributed in the twelve metal sites on the faces of supertetrahedron, exhibiting Cu/In co-occupancy with the ratio of 1 : 3. As for coreless CdÀ InÀ Q series (Figures 6b and 6c), Cd and In occupy twelve metal sites on the faces of supertetrahedron with the ratio of 1 : 1.…”

“…Discrete supertetrahedral Tn (n > 3) clusters are normally charge-and space-compensated by the following types of cations: (1) alkali metal cations; [40] (2) protonated amines or ammoniums; [41][42] (3) protonated nitrogen heterocycle molecules; [43] (4) transition metal complexes; [44] and (5) cations of ionic liquids (ILs). [45][46][47][48][49][50][51][52] Since the first crystallization of discrete supertetrahedral T5 chalcogenido cluster from ILs, [45] 32 of Tn clusters have been obtained in ILs. [46][47][48][49][50][51][52] This minireview summarizes the syntheses, crystal structures and selected properties of discrete Tn chalcogenido clusters obtained in ILs.…”

“…[45][46][47][48][49][50][51][52] Since the first crystallization of discrete supertetrahedral T5 chalcogenido cluster from ILs, [45] 32 of Tn clusters have been obtained in ILs. [46][47][48][49][50][51][52] This minireview summarizes the syntheses, crystal structures and selected properties of discrete Tn chalcogenido clusters obtained in ILs. Especially, the photocatalytic activity enhancement by monodispersing discrete Tn chalcogenido clusters in solvents is highlighted.…”