Water cluster encapsulated polyoxometalate-based hydrogen-bonded supramolecular frameworks (PHSFs) as a new family of high-capacity electrode materials

Recent advances in supramolecular self-assembly derived materials for high-performance supercapacitors

“…The encapsulation of water clusters into the porous structure of PHSFs improves the conductivity of the electrode material and stabilizes the entire space as a guest. Owing to the unique PHSF structure of (PHSFs) [Cu 2 (H 2 O) 4 H 2 (imbta) 4 ](PMo 12 O 40 ) 2 with numerous O–H⋯O interactions, the maximum specific capacitance of the compound 1-based electrode is 710 F g −1 at 1 A g −1 , 123 which is better than that of most of the reported POM-based electrodes.…”

“…In POM-HSFs, hydrogen bond interactions are important not only in self-assembled supramolecular frameworks but also provide electron transport and/or proton conduction pathways to enhance electrochemical performance. 122 Pang's group 123 prepared two nitrogen-rich organic ligands 1-imidazol-1-ylmethyl-1 H -benzotriazole (imbta) and 1-pyridine-3-ylmethyl-1 H -benzotriazole (pybta), and chose three PMo 12 O 40 3− Keggin POM, CuAc 2 ·H 2 O and AgNO 3 salts to prepare three novel water cluster enclosed polyoxometalate-based hydrogen bond supramolecular frameworks (PHSFs) [Cu 2 (H 2 O) 4 H 2 (imbta) 4 ](PMo 12 O 40 ) 2 ·6H 2 O (1), Cu(H 2 O) 2 H 4 (pybta) 4 (PMo 12 O 40 ) 2 ·2H 2 O (2), and [Ag 2 H 7 (pybta) 6 (PMo 12 O 40 ) 3 ]·12H 2 O (3) through a hydrothermal method. The detailed structure of the PHSF is displayed in Fig.…”

“…In POM-HSFs, hydrogen bond interactions are important not only in self-assembled supramolecular frameworks but also provide electron transport and/or proton conduction pathways to enhance electrochemical performance. 122 Pang's group 123 prepared two nitrogen-rich organic ligands 1-imidazol-1ylmethyl-1H-benzotriazole (imbta) and 1-pyridine-3-ylmethyl-1H-benzotriazole (pybta), and chose three PMo 12 123 which is better than that of most of the reported POM-based electrodes. MoS 2 features a two-dimensional (2D) layered structure similar to graphene, 124 which exists basically in 2H and 1T crystal phases.…”

Polyoxometalate-based metal–organic supramolecular architectures derived from two new pyrimidine-amide ligands as supercapacitors and multifunctional electrochemical sensors

“…To our knowledge, most of the reported POM-based metal–organic complexes are covalently bonded, while there are fewer studies of hydrogen-bonded POM-based complexes as electrode materials for both supercapacitor and electrochemical sensing applications. 28,29 In POM-based supramolecular complexes, hydrogen bonds play a crucial role in self-assembled supramolecular frameworks, where a large number of free POM anion clusters or metal–organic unit-modified POM fragments are connected with each other through hydrogen bonding interactions, which provides a pathway for proton conduction and/or electron transfer and thus contributes to the electrochemical properties. 30,31 Based on the above research background, two new organic ligands, N -(pyridin-3-ylmethyl)pyrimidine-4-carboxamide (pypa) and N , N ′-bis(4-pyrimidinecarboxamido)-1,5-pentane (bpap), were designed and synthesized (Scheme 1).…”

Bifuntional Materials Containing Preyssler‐type Polyoxometalates and Iron Phenanthroline Stabilized with Poly (Allylamine Hydrochloride) for Electrochromic Energy Storage Devices

“…In addition, the polyoxometalates has been an ideal electrode materials for energy storage applications due to unique electrochemical redox behavior and high stability in their oxidized and reduced states. [16,17] Yu et al [18] synthesized three new POM-based supramolecular frameworks and directly used as supercapacitor electrode material, which exhibited high specific capacitance and excellent capacitance retention. Zhu et al [19] prepared a Mxene/activated carbon/POMs triple hybrid electrode which facilitated charge storage, resulting in improved volumetric and gravimetric capacitances.…”