RESUMEN
We synthesized two hybrid organic-inorganic porous polymers (HPP) through the Heck reaction of 9,10 dibromoanthracene (A-Br2) or 1,3,6,8-tetrabromopyrene (P-Br4)/A-Br2 as co-monomers with octavinylsilsesquioxane (OVS), in order to afford OVS-A HPP and OVS-P-A HPP, respectively. The chemical structures of these two hybrid porous polymers were validated through FTIR and solid-state 13C and 29Si NMR spectroscopy. The thermal stability and porosity of these materials were measured by TGA and N2 adsorption/desorption analyses, demonstrating that OVS-A HPP has higher thermal stability (Td10: 579 °C) and surface area (433 m2 g-1) than OVS-P-A HPP (Td10: 377 °C and 98 m2 g-1) due to its higher cross-linking density. Furthermore, the electrochemical analysis showed that OVS-P-A HPP has a higher specific capacitance (177 F g -1 at 0.5 A F g-1) when compared to OVS-A HPP (120 F g -1 at 0.5 A F g-1). The electron-rich phenyl rings and Faradaic reaction between the π-conjugated network and anthracene moiety may be attributed to their excellent electrochemical performance of OVS-P-A HPP.
Asunto(s)
Antracenos , Pirenos , Porosidad , Electrodos , PolímerosRESUMEN
In this study, we synthesized three hybrid microporous polymers through Heck couplings of octavinylsilsesquioxane (OVS) with 2,5-bis(4-bromophenyl)-1,3,4-oxadiazole (OXD-Br2), tetrabromothiophene (Th-Br4), and 2,5-bis(4-bromophenyl)-3,4-diphenylthiophene (TPTh-Br2), obtaining the porous organic-inorganic polymers (POIPs) POSS-OXD, POSS-Th, and POSS-TPTh, respectively. Fourier transform infrared spectroscopy and solid state 13C and 29Si NMR spectroscopy confirmed their chemical structures. Thermogravimetric analysis revealed that, among these three systems, the POSS-Th POIP possessed the highest thermal stability (T5: 586 °C; T10: 785 °C; char yield: 90 wt%), presumably because of a strongly crosslinked network formed between its OVS and Th moieties. Furthermore, the specific capacity of the POSS-TPTh POIP (354 F g-1) at 0.5 A g-1 was higher than those of the POSS-Th (213 F g-1) and POSS-OXD (119 F g-1) POIPs. We attribute the superior electrochemical properties of the POSS-TPTh POIP to its high surface area and the presence of electron-rich phenyl groups within its structure.
RESUMEN
In this study, we used effective and one-pot Heck coupling reactions under moderate reaction conditions to construct two new hybrid porous polymers (named OVS-P-TPA and OVS-P-F HPPs) with high yield, based on silsesquioxane cage nanoparticles through the reaction of octavinylsilsesquioxane (OVS) with different brominated pyrene (P-Br4), triphenylamine (TPA-Br3), and fluorene (F-Br2) as co-monomer units. The successful syntheses of both OVS-HPPs were tested using various instruments, such as X-ray photoelectron (XPS), solid-state 13C NMR, and Fourier transform infrared spectroscopy (FTIR) analyses. All spectroscopic data confirmed the successful incorporation and linkage of P, TPA, and F units into the POSS cage in order to form porous OVS-HPP materials. In addition, the thermogravimetric analysis (TGA) and N2 adsorption analyses revealed the thermal stabilities of OVS-P-F HPP (Td10 = 444 °C; char yield: 79 wt%), with a significant specific surface area of 375 m2 g-1 and a large pore volume of 0.69 cm3 g-1. According to electrochemical three-electrode performance, the OVS-P-F HPP precursor displayed superior capacitances of 292 F g-1 with a capacity retention of 99.8% compared to OVS-P-TPA HPP material. Interestingly, the OVS-P-TPA HPP showed a promising HER value of 701.9 µmol g-1 h-1, which is more than 12 times higher than that of OVS-P-F HPP (56.6 µmol g-1 h-1), based on photocatalytic experimental results.