A molybdenum-selenium cluster compound containing transition metal coordination ions and its solvothermal preparation method and application

Abstract

The present invention relates to a molybdenum-selenium cluster compound containing transition metal complex ions and a solvent-thermal preparation method and application thereof. The molybdenum-selenium cluster compound of the present invention has a general structural formula: [M(en)3]Mo2O2Se2(Se2)2 or [M(dien)2]Mo2O2Se2(Se2)2, where M is Mn, Co or Ni; en is ethylenediamine, and dien is diethylenetriamine. The present invention uses a one-step solvent-thermal reaction to directly synthesize the molybdenum-selenium cluster compound containing transition metal complex ions, thereby simplifying the synthesis steps and improving the synthesis efficiency and product yield.

Description

Technical Field

[0001] The invention relates to the technical field of molybdenum-selenium cluster compounds, and in particular to a molybdenum-selenium cluster compound containing a transition metal coordination ion and a solvent-thermal preparation method and application thereof. Background Art

[0002] The preparation and properties of metal chalcogenides have attracted great research interest due to their important role in energy conversion, generation and storage applications in fields including catalysis, semiconductors, photovoltaics, batteries and photochemical synthesis. Molybdenum-chalcogenide (chalcogenide = O, S, Se) has the characteristics of narrow semiconductor energy gap and low hydrogen adsorption Gibbs free energy. Molybdenum-chalcogenide is one of the most widely used catalysts in petroleum hydrodesulfurization and is the most promising cheap catalyst to replace platinum in the electrochemical and photochemical production of hydrogen from water. At the same time, due to the existence of multiple variable valences such as +4, +5 and +6, molybdenum has rich reaction chemistry and easy redox conversion characteristics. Molybdenum-chalcogenide also has broad application prospects in the fields of catalysis and sulfur-based batteries. At present, people have synthesized and structurally characterized a series of molybdenum-chalcogenides with the general structural formula [Mo2X2(μ-E)2(E m E n )2] 2– (X = O, S, Se; E = S, Se; m, n = 1-4) molybdenum sulfide compounds, whose counter cations can be metal ions or organic cations. m E n )] 2– The structural characteristics are that they all contain a [Mo2X2(μ-E)2)] 2+ Double molybdenum core and two polysulfide ions S n 2– or polyselenium ion Se n 2– (n=1-4). Double molybdenum core [Mo2X2(μ-E)2)] 2+ Two MoX through two μ-E 2– The bridge ligands are connected, and each μ-E 2– The ligands are connected to two Mo atoms at the same time. A large number of [Mo2O2(μ-S)2(S m S n )2] 2–Type molybdenum-sulfur clusters, for example, molybdenum-sulfur clusters containing alkali metal ions K[(L)Mo2O2(μ-S)2(S2)2] (L is leu, met, thr, ser), molybdenum-sulfur clusters containing organic cations [(CH3)4N]2[Mo2O2(μ-S)2(S2)2], [(CH3)4N]2[Mo2O2(μ-S)2(S2)(S4)], [(CH3)4N]2[Mo2O2(μ-S)2(S2)(S4)]·CH3CN and [Ph4P]2[Mo2O2(μ-S)2(S2)2], and molybdenum-sulfur clusters containing organic ligands [Mo2O2(μ-S)2(DMF)3], Mo2O2(μ-S)2(Et2dtc)2 (dtc is dithiocarbamate). Compared with molybdenum-sulfur clusters, [Mo2O2(μ-Se)2(Se n )2] 2– There are relatively few studies on this binuclear molybdenum-selenide cluster, and only a few examples of this binuclear molybdenum-selenide cluster have been reported in the literature. These molybdenum-selenide clusters can be divided into different types according to their counter cations and polyselenium ions.

[0003] 1. Report on Molybdenum-Selenium Clusters Containing Alkali Metal Ions

[0004] (1) In 1990, Henkel used a multi-step reaction to prepare Na + ions. 24 ·6H2O and NaHSe were used as molybdenum and selenium sources, and Cys (Cys = L(+)-cysteine) was used as an organic ligand to prepare the molybdenum selenium cluster Na[(CH3)4N][Mo2O2(μ-Se)2(Cys)2]·7H2O. Due to the multi-step reaction synthesis, the yield was low, only 33%. (See: G. Henkel, G. Kampmann, B. Krebs, GJ Lamprecht, M. Nasreldin and A. G. Sykes, J. Chem. Soc., Chem. Commun., 1990, 15, 1014-1016.).

[0005] (2) In 1993, Eichhorn used a two-step reaction method to prepare K-containing +Molybdenum selenide clusters of ions. First, react Mo2(O2CCH3)4 (O2CCH3 is acetate) and K2Se4 in ethylenediamine for 3 hours, filter to obtain a clear solution, then add crown ether 2,2,2-crypt (2,2,2-crypt=1,4,7,10,13,16-hexaoxacyclooctadecane) to the filtrate, filter after the reaction, and let the filtrate stand for 6 days to obtain black crystals [K(2,2,2-crypt)]2[Mo2O2(μ-Se)2(Se2)] with a yield of 55%. The synthetic raw material K2Se4 is prepared by reacting potassium and selenium in liquid ammonia under the protection of nitrogen atmosphere. The DMSO and DMF solvents used in the synthesis should not contain water, and should be dried with molecular sieves before use and then distilled. (See: BWEichborn, JRGardner, ANZiebah, KJAhmetI and SGBott, Inorg. Chem., 1993, 32, 5412-5414.).

[0006] 2. Reports on Molybdenum-Selenium Clusters Containing Organic Cations

[0007] (1) In 1996, Mak used a two-step reaction method to prepare molybdenum selenide clusters containing organic cations. First, Mo(CO)6 and K2Se4 were reacted in ethanol at 100°C for 72 hours to obtain a black powder. Then, the black powder was reacted with Et4NCl·H2O in ethanol to prepare the compound (Et4N)2[(Mo2O2Se6) 0.20 ((Mo2O2Se6) 0.18 (Mo2O2Se6) 0.62 ], whose molybdenum selenium anion cluster consists of [Mo2O2(μ-Se)2)] 2+ Core and polyselenium ion Se2 2– 、Se3 2– 、Se4 2– The composition of polyselenium ions is 0.20, 0.18 and 0.62 respectively. The preparation of this compound requires two steps of reaction, the yield is low, and highly toxic Mo(CO)6 is used as a molybdenum source. The synthetic raw material K2Se4 is prepared under harsh conditions. The preparation method is to react potassium and selenium in a stoichiometric ratio in an autoclave at 400°C for 5 hours to obtain K2Se4 under the protection of a nitrogen atmosphere. (See: GC Guo and T. CW Mak, Inorg. Chem., 1998, 37, 6538-6540.).

[0008] (2) In 2022, Elliott used a multi-step reaction method to prepare (CH3)4N under nitrogen protection. +A certain amount of selenium powder is added to water, nitrogen is introduced into the water to remove oxygen in the water (i.e. degassing), then NaBH4 is added, and degassing with nitrogen is continued, and the reaction is carried out at 50°C for 40 minutes. Then, ammonium heptamolybdate (NH4)6Mo7O 24 , stirred overnight under nitrogen flow and filtered. Tetramethylammonium chloride (CH3)4NCl was added to the filtrate to generate a dark brown precipitate, which was washed with cold water, cold ethanol and ether respectively. The precipitate was dissolved in DMF to form a saturated solution. After the saturated solution was left to stand for several weeks, brown-black crystals [(CH3)4N]2[Mo2O2(μ-Se)2(Se2)2] were precipitated. 24 , Se and Na2Se2 were used instead of selenium powder, and the same synthesis method was used, and finally recrystallized in acetonitrile / ether mixed solvent to prepare [(CH3)4N]2[Mo2O2(μ-Se)2(Se2)(Se4)] 0.5 [Mo2O2(μ-Se)2(Se2)(Se3)] 0.25 [Mo2O2(μ-Se)2(Se2)] 0.25 . (See: A. Elliott, J. McAllister, L. Masaityte, MS Centellas, DLLong, AYGanin, YFSong, C.Bo and HNMiras, Chem. Commun., 2022, 58, 6906-6909.).

[0009] 3. Reports on Molybdenum-Selenium Clusters Containing Organic Selenium Ligands

[0010] (1) In 2006, Nguyen used MoCl5 and ( i Pr2PSe)2Se( i Pr = isopropyl) was reacted in ethanol for 1 hour to generate a yellow precipitate. After washing the precipitate with ethanol, it was recrystallized in dichloromethane to obtain brown crystals [Mo2O2(μ-Se)2(Se2P i Pr2)2], the molybdenum selenium cluster contains two organic selenium ligands Se2P i Pr2. Selenium source ( i Pr2PSe)2Se is composed of NEt3, i Pr2PCl, HSiCl3, Se are used as raw materials, through two-step reaction in hexane solvent and toluene solvent, and finally recrystallized in toluene. [Mo2O2(μ-Se)2( i Pr2PSe2)2] and ( iThe synthesis of Pr2PSe)2Se requires an inert environment and is performed in a standard Schlenk anhydrous and oxygen-free double-row tube operating system. (See: CQ Nguyen, A. Adeogun, M. Afzaal, MA Malik and P. O. Brien, Chem. Commun., 2006, 20, 2182-2184; CQ Nguyen, A. Adeogun, M. Afzaal, MA Malik and P. O. Brien, Chem. Commun., 2006, 20, 2179-2181.).

[0011] In summary, molybdenum sulfide clusters are an important component of metal sulfide compounds, and research in this field has always been of great importance. Many binuclear molybdenum sulfide clusters have been synthesized and structurally characterized, but compared with molybdenum sulfide clusters, research on binuclear molybdenum selenium clusters is relatively rare. Currently, there are only a few reports of molybdenum selenium clusters, and the counter cations of these molybdenum selenium clusters are alkali metal ions or organic cations, while molybdenum selenium clusters with transition metal ions as counter ions have not been reported in the literature.

[0012] At present, people prepare molybdenum selenide clusters, usually in an anhydrous and oxygen-free operating system, using volatile organic compounds as solvents, through a multi-step reaction. First, Mo(CO)6, (NH4)6Mo7O 24 ,MoCl5,K2Se4,NaHSe,Na2Se2,( i Pr2PSe)2Se and other compounds are used as intermediates (molybdenum source and selenium source) for the synthesis of molybdenum selenium clusters. The preparation of these intermediates needs to be carried out under harsh conditions such as anhydrous and oxygen-free inert or high temperature. For example, Mo(CO)6 and ( i The preparation of Pr2PSe)2Se was completed under the protection of N2 gas, and the preparation of K2Se4 and Na2Se2 was obtained by reacting at 400°C for 5 hours under nitrogen atmosphere. Secondly, the synthesis of molybdenum selenium clusters is usually carried out in volatile organic solvents such as acetonitrile, ether, toluene, and dichloromethane, and requires multiple steps of operation such as repeated extraction, precipitation, crystallization, and recrystallization with organic solvents. These solvents are usually subjected to water removal treatment such as distillation before use, which consumes energy and is not conducive to environmental protection. At present, the molybdenum selenium clusters prepared and studied by people all use alkali metal ions and organic cations as counter cations. There is no literature report on the research of molybdenum selenium clusters containing transition metal complex ions, and there is no literature report on the research of preparing molybdenum selenium clusters by one-step reaction.

[0013] At present, people have synthesized molybdenum-selenide clusters with alkali metal ions and organic cations as counter cations using volatile organic compounds as solvents. The shortcomings of the preparation of these reported molybdenum-selenide clusters are: (1) it is necessary to first synthesize K2Se4, NaHSe, Na2Se2, ( i Pr2PSe)2Se and other selenium compounds are used as raw materials (selenium sources). The preparation of these chemical selenium sources needs to be carried out in anhydrous and oxygen-free inert or at high temperature and other harsh conditions. There is no literature report on the direct use of elemental selenium powder as a selenium source; (2) Mo(CO)6, (NH4)6Mo7O 24 , MoCl5 as a molybdenum source, Mo(CO)6 is a highly toxic substance; (3) The preparation of molybdenum selenium clusters requires two or more steps of reaction, and the yield is generally low. There is no literature report on the preparation of molybdenum selenium clusters by one-step reaction; (4) The preparation of molybdenum selenium clusters usually has to be carried out under complex anhydrous and oxygen-free inert conditions, and requires a large amount of volatile solvents such as acetonitrile, ether, toluene, and dichloromethane. These solvents usually need to be distilled and dehydrated before use, which consumes energy and is not conducive to environmental protection. (5) There are many synthesis steps and the product yield is low. For example, the yield of Na[(CH3)4N][Mo2O2(μ-Se)2(Cys)2]·7H2O is only 33%. Therefore, it is urgent to develop a more efficient and environmentally friendly production method. Summary of the invention

[0014] Therefore, the technical problem to be solved by the present invention is to overcome the problems in the prior art: (1) the need to first synthesize K2Se4, NaHSe, Na2Se2, ( i Pr2PSe)2Se and other selenium compounds are used as raw materials (selenium sources). The preparation of these chemical selenium sources needs to be carried out in anhydrous and oxygen-free inert or at high temperature and other harsh conditions. There is no literature report on the direct use of elemental selenium powder as a selenium source; (2) Mo(CO)6, (NH4)6Mo7O 24 , MoCl5 as a molybdenum source, Mo(CO)6 is a highly toxic substance; (3) The preparation of molybdenum selenide clusters requires two or more steps of reaction, and the yield is generally low. There is no literature report on the preparation of molybdenum selenide clusters by one-step reaction; (4) The preparation of molybdenum selenide clusters is usually carried out under complex anhydrous and oxygen-free inert conditions. Whether it is the synthesis of intermediates or the preparation, crystallization and recrystallization of molybdenum selenide clusters, a large amount of volatile solvents such as acetonitrile, ether, toluene, and dichloromethane are required. Organic solvents have safety hazards such as flammability and easy leakage, and these solvents are usually distilled and other water removal treatments before use, which consumes energy and is not conducive to environmental protection. (5) There are many synthesis steps and the product yield is low.

[0015] In order to solve the above technical problems, the present invention provides a molybdenum-selenium cluster containing transition metal complex ions and a solvothermal preparation method thereof. The preparation method of the present invention utilizes the chelating coordination effect of ethylene polyamine, and synthesizes the molybdenum-selenium cluster containing transition metal complex ions through a one-step reaction under solvothermal conditions. The synthesis method is simple to operate, and simple sodium molybdate inorganic salt and selenium powder are used as molybdenum source and selenium source respectively, avoiding the need to prepare special molybdenum and selenium compounds as molybdenum source and selenium source in the traditional method under anhydrous and anaerobic conditions. The intermediate step, using simple and readily available raw materials, without intermediate synthesis steps, synthesizing the molybdenum-selenium cluster containing transition metal complex ions by a one-step reaction improves the product yield. The reaction does not need to be carried out under anhydrous and anaerobic conditions, nor does it require a large amount of organic solvents used in the traditional preparation method. Only two solvents, ethylene polyamine and ethanol, are needed, and the solvent does not need to be further dehydrated. Ethylene polyamine is not only a reaction solvent but also a chelating agent for transition metal complex ions. Ethylene polyamine reacts with transition metal complex ions in situ to form transition metal complex cations, which serve as counter ions of molybdenum-selenium clusters, thereby forming molybdenum-selenium clusters containing transition metal complex ions.

[0016] The first aspect of the present invention aims to overcome the problem that the existing technology for synthesizing molybdenum selenium clusters requires the synthesis of (NH4)6Mo7O 24 , Mo2(O2CCH3)4, Mo(CO)6, K2Se4, NaHSe, Na2Se2, ( i Intermediates such as Pr2PSe)2Se serve as intermediate steps for molybdenum source and selenium source, and the synthesis of these intermediates needs to be carried out under harsh conditions such as high temperature of 400°C in anhydrous and oxygen-free conditions, and a large amount of volatile organic solvents such as acetonitrile, toluene, and ether are used.

[0017] The second aspect of the present invention aims to overcome the defects of the existing synthesis technology of molybdenum selenium clusters, which requires multi-step reactions, and these reactions usually need to be carried out at a high temperature above 400 ° C (such as K2Se4), or in a complex anhydrous and oxygen-free operating system (such as Mo(CO)6, ( i Pr2PSe)2Se). Due to the many synthesis steps, the final product yield is low.

[0018] In order to solve the above technical problems, the present invention is implemented by the following scheme:

[0019] The first object of the present invention is to provide a molybdenum-selenium cluster compound containing a transition metal ligand ion, wherein the molybdenum-selenium cluster compound has a general structural formula of [M(en)3]Mo2O2Se2(Se2)2 or [M(dien)2]Mo2O2Se2(Se2)2, wherein M is Mn, Co or Ni; en is ethylenediamine, and dien is diethylenetriamine. 2+ and [M(dien)2]2+ Medium 2+ The coordination number is 6, which is an octahedral ion. [Mo2O2(μ-Se)2(Se2)] 2– By a [Mo2O2(μ-Se)2)] 2+ Double molybdenum core and two polyselenium ions Se2 2– Composition. Cationic core [Mo2O2(μ-Se)2)] 2+ Two MoO through two μ-Se 2– Each μ-Se 2– The ligand is simultaneously attached to two Mo atoms.

[0020] The second object of the present invention is to provide a method for preparing a molybdenum-selenium cluster containing a transition metal complex ion, comprising the following steps: mixing and stirring a salt containing M, a molybdenum source, and a selenium source in an ethylene polyamine solvent, heating the mixture for reaction, and obtaining the molybdenum-selenium cluster containing a transition metal complex ion; wherein M in the salt containing M is Mn, Co, or Ni.

[0021] In one embodiment of the present invention, the M-containing salt is selected from one or more of MnCl2, CoCl2 and NiCl2.

[0022] In one embodiment of the present invention, the molybdenum source is selected from Na2MoO4 and / or MoO3.

[0023] In one embodiment of the present invention, the selenium source is selected from Se and / or Na2Se.

[0024] In one embodiment of the present invention, the ethylene polyamine solvent is selected from ethylenediamine and / or diethylenetriamine. Ethylenediamine (boiling point: 116.5°C) and diethylenetriamine (boiling point: 207°C) have high boiling points, are not volatile, are not flammable, avoid environmental pollution, and improve the safety of the preparation process. In the present invention, ethylene polyamine is both a reaction solvent and a chelating agent for transition metal complex ions. As a solvent, ethylene polyamine has high polarity and strong solubility, avoids the formation of metal selenide MSe (M is transition metal Mn, Co, Ni) and MoSe2 precipitation, is conducive to the crystallization of molybdenum selenium clusters, thereby forming molybdenum selenium cluster crystals and improving the purity of the product; at the same time, ethylene polyamine has a strong chelating coordination ability, and it is easy to form complex ions with transition metal complex ions, and then combine with molybdenum selenium cluster anions to form molybdenum selenium clusters containing transition metal complex ions. And when the structure of ethylene polyamine changes, the structure of the molybdenum selenium cluster anions remains unchanged, and the product semiconductor energy gap is regulated by the difference of transition metal complex ions.

[0025] In one embodiment of the present invention, the molar ratio of the M-containing salt, the molybdenum source and the selenium source is 1:2:6 to 1:2:8.

[0026] In one embodiment of the present invention, the conditions of the heating reaction are: the reaction temperature is 150-180° C., and the reaction time is 4-5 days.

[0027] In one embodiment of the present invention, the purification of molybdenum-selenide clusters containing transition metal complex ions is also included, and the steps are: after heating, cooling to room temperature, filtering to obtain a filter cake, and washing the filter cake with a detergent to obtain the molybdenum-selenide clusters containing transition metal complex ions.

[0028] Furthermore, the detergent is selected from ethanol.

[0029] The third object of the present invention is to provide the molybdenum-selenide cluster compound containing transition metal complex ions or the use of the molybdenum-selenide cluster compound containing transition metal complex ions in catalytic photodegradation of organic dyes.

[0030] Furthermore, the organic dyes include but are not limited to methylene blue (MB), crystal violet (CV), rhodamine B (RhB), methyl orange (MO) and other organic dyes.

[0031] The above technical solution of the present invention has the following advantages compared with the prior art:

[0032] The method for synthesizing the molybdenum-selenium cluster compound containing transition metal complex ions of the present invention is simple, and utilizes a one-pot solvent thermal method to omit the intermediate steps in the traditional synthesis method, and uses cheap and easily available Na2MoO4 and Se as molybdenum sources and selenium sources to obtain the molybdenum-selenium cluster compound containing transition metal complex ions for the first time through a one-step solvent thermal reaction; a large amount of organic solvents in the traditional synthesis method are not used; the product is easy to separate and purify, and the yield is high; the molybdenum-selenium cluster compound has a clear and stable structure; the semiconductor energy gap and semiconductor performance of the molybdenum-selenium cluster compound can be regulated by different transition metal complex ions.

[0033] (1) The present invention uses a one-step solvent thermal reaction to directly synthesize molybdenum selenide cluster compounds containing transition metal complex ions, which simplifies the synthesis steps and improves the synthesis efficiency and product yield.

[0034] (2) No volatile or flammable organic solvents are used, thus avoiding environmental pollution and improving the safety of the synthesis and preparation of molybdenum selenium clusters. No organic solvents other than ethylenediamine (EN), diethylenetriamine (DIEN) and ethanol are used. Ethylenediamine, diethylenetriamine and ethanol do not require any pretreatment including distillation and water removal before use.

[0035] (3) Using cheap and readily available Na2MoO4 and Se as molybdenum and selenium sources, there is no need to synthesize specific molybdenum and selenium compounds as intermediates, such as Mo(CO)6, MoCl5, K2Se4, NaHSe, Na2Se2, ( iThe intermediate products such as Pr2PSe)2Se reduce energy consumption, are cheap and easy to obtain, safe and non-toxic. The reactants can directly synthesize molybdenum selenium clusters through a one-step solvent thermal reaction at a relatively low temperature (such as 150°C), without intermediate steps. The preparation process does not require an anhydrous and oxygen-free operating system, and there are no intermediate steps, which improves the synthesis efficiency.

[0036] (4) The energy gap and semiconductor properties of molybdenum-selenide cluster semiconductors can be regulated by different transition metal ligand ions.

[0037] (5) The molybdenum-selenide cluster containing transition metal ions of the present invention has catalytic activity for photodegradation of organic dyes, and the catalytic degradation rate of organic dyes such as methylene blue (MB) and crystal violet (CV) reaches more than 88%.

[0038] (6) To accumulate theoretical and practical experience for the design and synthesis of new molybdenum-selenide clusters. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0040] Figure 1 It is a schematic diagram of the preparation process of [M(en)3]Mo2O2Se2(Se2)2 and [M(dien)2]Mo2O2Se2(Se2)2 of the present invention.

[0041] Figure 2 [Mn(en)3]Mo2O2Se2(Se2)2 in the present invention 2+ (a) and [Mn(dien)2]Mo2O2Se2(Se2)2 2+ (b) Structure diagram of the ligand ion.

[0042] Figure 3 The present invention [Mo2O2Se2(Se2)2] 2- Cluster anion structure diagram. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0044] Example 1: [Mn(en)3]Mo2O2Se2(Se2)2

[0045] MnCl2·4H2O (0.099 g, 0.5 mmol), Na2MoO4 (0.206 g, 1.0 mmol) and Se (0.237 g, 4.0 mmol) were added to a 3 ml ethylenediamine (en) mixed solution, stirred for 10 minutes, and the mixture was placed in a stainless steel reactor with polytetrafluoroethylene and reacted at 150°C for 5 days. After cooling to room temperature, black crystals were precipitated, filtered, washed twice with 5 ml ethanol, and vacuum dried to obtain 0.382 g of crystals with a yield of 82% (calculated based on Na2MoO4). Elemental analysis: C7.56, H 2.48, N8.84%; theoretical value of element content: C 7.73, H 2.59, N 9.01%. Infrared absorption spectrum data (KBr, cm -1 ): 3417(s),3159(w),3057(w),2923(m),2862(m),2082(w),1574(s),1491(m),1382(w),1322(m),1151(w),1075(w),962(m),892(w),867(m),666(w),634(m),499(w),451(w). Solid-state absorption spectroscopy determination: semiconductor energy gap E g =1.67eV.

[0046] Example 2: [Co(en)3]Mo2O2Se2(Se2)2

[0047] CoCl2·6H2O (0.119 g, 0.5 mmol), Na2MoO4 (0.206 g, 1.0 mmol) and Se (0.237 g, 4.0 mmol) were added to a 3 ml ethylenediamine (en) mixed solution, stirred for 10 minutes, and the mixture was placed in a stainless steel reactor with polytetrafluoroethylene and reacted at 150°C for 5 days. After cooling to room temperature, black crystals were precipitated, filtered, washed twice with 5 ml ethanol, and vacuum dried to obtain 0.365 g of crystals with a yield of 78% (calculated based on Na2MoO4). Elemental analysis: C7.56, H 2.43, N8.79%; theoretical value of element content: C 7.69, H 2.58, N 8.97%. Infrared absorption spectrum data (KBr, cm -1 ): 3299(w),3212(w),3100(m),2916(w),2869(w),2351(w),2023(w),1576(s),1447(m),1301(w),1252(w),1155(w),1086(m),1010(m),941(s),897(m),816(w),666(w),558(m),462(w). Solid-state absorption spectroscopy determination: semiconductor energy gap E g =1.55eV.

[0048] Example 3: [Ni(en)3]Mo2O2Se2(Se2)2

[0049] NiCl2·6H2O (0.119 g, 0.5 mmol), Na2MoO4 (0.206 g, 1.0 mmol) and Se (0.237 g, 4.0 mmol) were added to a 3 ml ethylenediamine (en) mixed solution, stirred for 10 minutes, and the mixture was placed in a stainless steel reactor with polytetrafluoroethylene and reacted at 150°C for 5 days. After cooling to room temperature, black crystals were precipitated, filtered, washed twice with 5 ml ethanol, and vacuum dried to obtain 0.374 g of crystals with a yield of 80% (calculated based on Na2MoO4). Elemental analysis: C7.51, H 2.45, N8.75%; theoretical value of element content: C 7.69, H 2.58, N 8.97%. Infrared absorption spectrum data (KBr, cm -1 ): 3444(w),3207(m),3123(s),2906(m),2856(m),2362(w),2095(w),1576(s),1448(m),1379(w),1315(m),1280(w),1117(m),1072(s),994(s),959(m),880(w),692(w),583(w),498(m). Solid-state absorption spectroscopy determination: semiconductor energy gap E g =1.57eV.

[0050] Example 4: [Mn(dien)2]Mo2O2Se2(Se2)2

[0051] MnCl2h4H2O (0.099 g, 0.5 mmol), Na2MoO4 (0.206 g, 1.0 mmol) and Se (0.237 g, 4.0 mmol) were added to 3 ml of diethylenetriamine (dien) mixed solution, stirred for 10 minutes, and the mixture was placed in a stainless steel reactor with polytetrafluoroethylene and reacted at 150°C for 5 days. After cooling to room temperature, black crystals were precipitated, filtered, washed twice with 5 ml of ethanol, and vacuum dried to obtain 0.369 g of crystals with a yield of 77% (calculated based on Na2MoO4). Elemental analysis: C9.85, H2.58, N 8.59%; theoretical value of element content: C 10.02, H 2.73, N 8.76%. Infrared absorption spectrum data (KBr, cm -1): 3352(m), 2939(m), 2868(w), 2131(w), 1630(m), 1580(m), 1467(s), 1371(s), 1296(s), 1145(m), 1042(m), 968(w), 914(w), 811(m), 731(m), 601(m), 574(m), 504(w). Solid-state absorption spectroscopy determination: semiconductor energy gap E g =1.63eV.

[0052] Example 5: [Co(dien)2]Mo2O2Se2(Se2)2

[0053] Add C℃l2·6H2O (0.119 g, 0.5 mmol), Na2MoO4 (0.206 g, 1.0 mmol) and Se (0.237 g, 4.0 mmol) to 3 ml of ethylenediamine (en) mixed solution, stir for 10 minutes, put the mixture into a stainless steel reactor with polytetrafluoroethylene, and react at 150℃ for 5 days. After cooling to room temperature, black crystals precipitate, filter, wash twice with 5 ml of ethanol, and vacuum dry to obtain 0.390 g of crystals with a yield of 81% (calculated based on Na2MoO4). Elemental analysis: C9.86, H 2.65, N8.55%; theoretical value of element content: C 9.98, H 2.72, N 8.73%. Infrared absorption spectrum data (KBr, cm -1 ): 3443(m),3299(s),3237(s),2935(m),2880(m),2362(w),2036(w),1567(m),1453(s),1392(s),1320(m),1271(w),1083(m),1004(s),974(s),614(m),589(m),454(m). Solid-state absorption spectroscopy determination: semiconductor energy gap E g =1.58eV.

[0054] Example 6: [Ni(dien)2]Mo2O2Se2(Se2)2

[0055] NiCl2·6H2O (0.119 g, 0.5 mmol), Na2MoO4 (0.206 g, 1.0 mmol) and Se (0.237 g, 4.0 mmol) were added to 3 ml of ethylenediamine (en) mixed solution, stirred for 10 minutes, and the mixture was placed in a stainless steel reactor with polytetrafluoroethylene and reacted at 150°C for 5 days. After cooling to room temperature, black crystals were precipitated, filtered, washed twice with 5 ml of ethanol, and vacuum dried to obtain 0.404 g of crystals with a yield of 84% (calculated based on Na2MoO4). Elemental analysis: C9.81, H 2.62, N8.57%; theoretical value of element content: C 9.98, H 2.72, N 8.73%. Infrared absorption spectrum data (KBr, cm -1 ): 3408(m),3177(s),3103(s),2915(m),2875(m),1577(s),1458(m),1311(m),1142(w),1084(w),1028(s),945(m),874(w),806(w),766(w),618(w),553(w),481(w). Solid-state absorption spectroscopy determination: semiconductor energy gap E g =1.53eV.

[0056] Performance Testing

[0057] The molybdenum selenium clusters containing transition metal complex ions obtained in Example 1, Example 2, Example 3, Example 4, Example 5, and Example 6 were used to photocatalytically degrade organic dyes CV and MB. The experimental results are shown in Table 1.

[0058] Degradation experiment process: Take a certain amount of molybdenum selenide cluster containing transition metal ions, add it to the solution of organic dye, irradiate the organic dye solution with Xe lamp light source under constant stirring, take a small amount of solution at certain intervals, measure the visible-ultraviolet absorption spectrum of the solution, detect the concentration changes of CV and MB according to the intensity of the maximum absorption peak of CV and MB, and then calculate the degradation percentage of CV and MB.

[0059] Table 1

[0060]

[0061] It can be seen that the molybdenum-selenide cluster containing transition metal ions obtained in the present invention has good catalytic activity for photodegradation of organic dyes.

[0062] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A molybdenum-selenium cluster compound containing a transition metal complex ion, characterized in that: The molybdenum-selenide cluster compound has the general structural formula: [M(en)3]Mo2O2Se2(Se2)2 or [M(dien)2]Mo2O2Se2(Se2)2, where M is Mn, Co or Ni; en is ethylenediamine, and dien is diethylenetriamine.

2. A method for preparing a molybdenum-selenium cluster compound containing a transition metal complex ion according to claim 1, characterized in that: The method comprises the following steps: mixing and stirring a salt containing M, a molybdenum source and a selenium source in an ethylene polyamine solvent, and heating for reaction to obtain the molybdenum-selenium cluster containing transition metal complex ions; wherein M in the salt containing M is Mn, Co or Ni; The molybdenum source is selected from Na2MoO4 and / or MoO3; The selenium source is selected from Se and / or Na2Se; The molar ratio of the M-containing salt, the molybdenum source, and the selenium source is 1:2:6 to 1:2:8; The ethylene polyamine solvent is selected from ethylenediamine or diethylenetriamine; The conditions of the heating reaction are: the reaction temperature is 150-180° C., and the reaction time is 4-5 days.

3. The preparation method according to claim 2, characterized in that: The M-containing salt is selected from one or more of MnCl2, CoCl2 and NiCl2.

4. The preparation method according to claim 2, characterized in that: The method also includes the purification of molybdenum-selenium cluster compounds containing transition metal complex ions, and the steps are: after heating, cooling to room temperature, filtering to obtain a filter cake, and washing the filter cake with a detergent to obtain the molybdenum-selenium cluster compound containing transition metal complex ions.

5. Use of the molybdenum-selenide cluster compound containing transition metal complex ions as claimed in claim 1 in catalytic photodegradation of organic dyes.

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