A series of POM-based compounds by tuning coordination groups and spacers of ligands: electrocatalytic, capacitive and photoelectrocatalytic properties

Seven polyoxometalate-based compounds were synthesized under hydrothermal conditions, namely [Co(H(2)Ptep)(HPtep)(H2O)(2)(PW11CoO39)]center dot 4.5H(2)O (1), {[Cu(H(3)Ptep)(2)(H(2)Ptep)(2)][SiW12O40]}center dot(SiW12O40)(2)center dot 8H(2)O (2), {Cu-3(H(2)Ptpi)(2)(Ptpi)(2)(H2O)(5)[(PMo11CuO39)(2)]}center dot 6H(2)O (3), [Co(H(2)Ptpi)(2)(HPtpi)(2)(SiMo12O40)(2)]center dot 2H(2)O (4), [Co-3(Ptpi)(2)(H2O)(6)(TeMo6O24)]center dot 2H(2)O (5), [Co2Na(HPtpi)(H2O)(7.5)(TeMo6O24)]center dot 3.5H(2)O (6), [Cu(HZtpi)(H2O)(2)(CrMo6(OH)(6)O-18)]center dot 5H(2)O (7) (Ptep = 1-[2-(3-pyridin-4-yl-[1,2,4]triazol-4-yl)-ethyl]-piperazine, Ptpi = 1-[2-(3-pyridin-4-yl-[1,2,4]triazol-4-yl)-propyl]-imidazol, Ztpi = 1-[2-(3-pyrazin-4-yl-[1,2,4]triazol-4-yl)-propyl]-imidazol). Compounds 1-4 are all based on Keggin anions, especially 1 and 3 containing TMs monosubstituted Keggin anions. Compounds 5-7 are all based on Anderson anions. Compounds 1-4, 6 and 7 exhibit 0D, 1D and 2D structures, while compound 5 has a 3D structural framework. These seven compounds have excellent electrochemical properties and can be used as sensors for the amperometric detection of Cr(vi) and NO2-. Among them, 1 and 4 possess favorable capacitance performance. Furthermore, compounds 3 and 4 have photoelectrocatalytic properties and can be used for the photoelectrocatalytic degradation of organic dye MB.

Automated summary

Seven polyoxometalate-based compounds were synthesized under hydrothermal conditions, exhibiting excellent electrochemical and photoelectrocatalytic properties. Compounds 1 and 4 show favorable capacitance performance, while compounds 3 and 4 can be used for the photoelectrocatalytic degradation of organic dye MB.