Polymolybdate Derivative With Arsenic As Heteroatom Synthesis And Performance Studies

As-molybdenum polyacid compounds are an important part of polyacid chemistry.Because of their complex and changeable spatial structure,reversible multi-electron transfer ability and other excellent chemical properties,they have been widely used in supercapacitors,electrode materials preparation and photocatalysis.At present,there are relatively few reports on polymolybdate derivatives with arsenic as heteroatom,and the study of electrochemical energy storage properties is not very deep.Eight new arsenolybdate derivatives were synthesized by hydrothermal synthesis by selecting and matching suitable organic ligands and adjusting the p H of solution.By X-ray single crystal diffraction and analysis of its elemental composition,the formula is as follows:{Cu（bpy）₂}[{Cu ^Ⅱ（bpy）₂}₂{As ₂^ⅢAs ^VMo ₈^VIV₄^VO₄₀)]·4H₂O（1）,{Cl(Cu^Ⅱ（phen）₂)₂}{As Mo₁₂O₄₀}·H₂O（2）,（Hbipy）（bipy）₂{As ₂^ⅢAs ^VMo ₈^VIV₄^VO₄₀}]·2H₂O（3）,（Himi）₅{As ₂^ⅢAs ^VMo₈V₄O₄₀}]·2H₂O（4）,（apy）₄[(V_0.5（apy）(As Mo₁₂O₄₀)]·H₂O（5）,[{Cu（bib）₄}{Cu_0.5V_0.5O}₂{As Mo₈V₄O₄₀}]·2H₂O（6）,[{Cu ^Ⅱ（bpy）}{Cu ^Ⅱ（bpy）₂}₂{V^IVO}₂{As Mo ^VIMo ₇^VV₄^VO₄₀}]·H₂O（7）,[{Cu₂^Ipz（phen）₂}₂{Cu^ICu^ⅡO（phen）₂}₂{As Mo^VMo₁₁^VIO₄₀}]（8）,（bib=1,4-Bis（imidazol-1-ylmethyl）benzene,bpy=2,2’-联吡啶,phen=1,10-菲罗啉,pz=pyrazine,bipy=4,4’-联吡啶,imi=imidazole,apy=2-氨基吡啶）。electrochemical properties photocatalytic properties;super capacitor performanceThe analysis of crystal structure shows that compound 1 is composed of a Keggin structure unit with symmetrical arsenic cap and three Cu（bipy）₂connecting units;compound 2 consists of two{Cl（Cu（phen）₂）₂}fragments,two{As Mo₁₂O₄₀}polyoxoanions and one lattice water molecule;compound 3 is replaced by a tetra-vanadium with a symmetric arsenic cap Keggin a polyoxoanion and three 4,4’-bipyridine,Compound 4 is similar to compound 3,All have the same four vanadium substituted Keggin polyoxoanions,Unlike compound 3,the ligand of compound 4 is five floating imidazole;compound 5 is composed of a{As Mo₁₂}cluster with a double vanadium cap and five diaminopyridine organic ligands.Compound 6 is a one-dimensional structure formed by the combination of copper-vanadium co-occupying double-cap modified Keggin clusters and long-chain ligand bib;Compound 7 was replaced by tetra-vanadium Keggin cluster with 2,One-dimensional structure of bipyridine formed by metal copper;Compound 8 is a one-dimensional structure formed by the complex formed by the Keggin structure unit with symmetrical double copper cap and o-phenanthroline.The energy storage properties of 8 compounds as supercapacitors are also studied.By analyzing and comparing the experimental data,it can be concluded that the specific capacitance of compounds 1-3 is higher than that of other zero-dimensional compounds at the same current density,because compounds 1-3 are all one-dimensional compounds.The addition of copper plays a great role in the transmission of electrons and ions,and their cyclic stability is better than that of zero-dimensional compounds.Although the specific capacitance and cyclic stability of compounds 4 and 5 are worse than those of compounds 1-3,they are slightly better than those of compounds 6-8,because the modification of polyacid clusters by metal complexes formed with copper ions and organic ligands is beneficial to the transport of electrons.Compound 1-8 has good catalytic effect on both hydrogen peroxide and ascorbic acid,and is a good alternative material for bifunctional sensors.The MB、Rh B and MO dyes were degraded by 8 compounds under ultraviolet mercury lamp irradiation.The results show that 8 compounds have better degradation effect on the three dyes.The degradation effect of dimensionality and metal complex modification is better,which may be that the addition of metal and organic ligands is beneficial to the separation and migration of electrons and ions in photocatalytic process.