In this study we synthesized two tetraphenyl-p-phenylenediamine-based covalent organic frameworks (TPPDA-TPPyr and TPPDA-TPTPE COFs) for potential use in high-performance electrochemical supercapacitors. This excellent performance arose from their structures containing redox-active triphenylamine derivatives and their high surface areas.

In this study we synthesized two tetraphenyl-p-phenylenediamine-based covalent organic frameworks (TPPDA-TPPyr and TPPDA-TPTPE COFs) for potential use in high-performance electrochemical supercapacitors. This excellent performance arose from their structures containing redox-active triphenylamine derivatives and their high surface areas.

In this study we synthesized two tetraphenyl-p-phenylenediamine-based covalent organic frameworks (TPPDA-TPPyr and TPPDA-TPTPE COFs) for potential use in high-performance electrochemical supercapacitors. This excellent performance arose from their structures containing redox-active triphenylamine derivatives and their high surface areas.

Nanostructured Co3O4-graphene hybrid catalysts are fabricated by a one-step vacuum kinetic spray technique from microparticles of Co3O4 and graphite powders. The Co3O4-graphene hybrid catalysts with various Co3O4 contents are studied concerning the oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) in 1.0 M KOH, as well as, H2O2 sensing in 0.1 M NaOH. We find that increasing graphene content in the hybrid catalysts results in an overall improvement of the OER electrocatalytic activity due to the enhancement in the charge transfer kinetics. The hybrid catalyst with 25 wt% Co3O4 reveals the optimum electrocatalytic activity toward the OER with the lowest overpotential (η) of 283 mV@ 10 mA cm−2 and superior reaction kinetics with a low Tafel slope of 25 mV.dec−1. Besides, the OER stability at 50 mA cm−2 for 50 h in 1.0 M KOH was verified. The hybrid catalyst with 50 wt% Co3O4 revealed the highest activity toward the HER with η of 108 mV@ 10 mA cm−2, Tafel slope of 90 mV.dec−1, and stability at 50 mA cm−2 for nearly 30 h. Moreover, it reveals ultrahigh H2O2 amperometric detection with superior sensitivity of 18,110 μA mM−1 cm−2, linear detection range from 20 μM to 1 mM, and a limit of detection of 0.14 μM.

We successfully synthesized two different kinds of hyper-crosslinked porous organic polymers (CPOPs) based on tetraphenylanthraquinone units by a reaction of 9,10-bis(diphenylmethylene)- 9,10-dihydroanthracene (An-4Ph) as the building unit with formaldehyde dimethyl acetal and 2,4,6-trichloro-1,3,5-triazine as two external crosslinkers by using a simple and friendly one-step Friedel−Crafts polymerization in the presence anhydrous FeCl3 as a catalyst to afford An-CPOP-1 and An-CPOP-2 as a black solid with high yield, respectively. Fourier-transform infrared (FTIR) and NMR spectroscopy were confirmed the chemical structures of the synthesized monomers and the corresponding polymers. Both An-CPOP-1 and An-CPOP-2 showed amorphous character, outstanding thermal stability, and high BET surface area (up to 1000 m2/g) with microporosity and mesoporosity architectures based on XRD, TGA analyses and N2 adsorption/desorption measurements. Interestingly, TEM and SEM images revealed that An-CPOP-1 had regular tubular nanotubes structure without using template or surfactant or carbonization at the elevated temperature. The as-prepared An-CPOP-2 exhibited a high specific capacitance of 98.4 F g−1 at a current density of 0.5 A g−1 and excellent cycling stability (95.3% capacitance retention over 2000 cycles), which could be used as good material for energy storage application.

We successfully synthesized two different kinds of hyper-crosslinked porous organic polymers (CPOPs) based on tetraphenylanthraquinone units by a reaction of 9,10-bis(diphenylmethylene)- 9,10-dihydroanthracene (An-4Ph) as the building unit with formaldehyde dimethyl acetal and 2,4,6-trichloro-1,3,5-triazine as two external crosslinkers by using a simple and friendly one-step Friedel−Crafts polymerization in the presence anhydrous FeCl3 as a catalyst to afford An-CPOP-1 and An-CPOP-2 as a black solid with high yield, respectively. Fourier-transform infrared (FTIR) and NMR spectroscopy were confirmed the chemical structures of the synthesized monomers and the corresponding polymers. Both An-CPOP-1 and An-CPOP-2 showed amorphous character, outstanding thermal stability, and high BET surface area (up to 1000 m2/g) with microporosity and mesoporosity architectures based on XRD, TGA analyses and N2 adsorption/desorption measurements. Interestingly, TEM and SEM images revealed that An-CPOP-1 had regular tubular nanotubes structure without using template or surfactant or carbonization at the elevated temperature. The as-prepared An-CPOP-2 exhibited a high specific capacitance of 98.4 F g−1 at a current density of 0.5 A g−1 and excellent cycling stability (95.3% capacitance retention over 2000 cycles), which could be used as good material for energy storage application.

We successfully synthesized two different kinds of hyper-crosslinked porous organic polymers (CPOPs) based on tetraphenylanthraquinone units by a reaction of 9,10-bis(diphenylmethylene)- 9,10-dihydroanthracene (An-4Ph) as the building unit with formaldehyde dimethyl acetal and 2,4,6-trichloro-1,3,5-triazine as two external crosslinkers by using a simple and friendly one-step Friedel−Crafts polymerization in the presence anhydrous FeCl3 as a catalyst to afford An-CPOP-1 and An-CPOP-2 as a black solid with high yield, respectively. Fourier-transform infrared (FTIR) and NMR spectroscopy were confirmed the chemical structures of the synthesized monomers and the corresponding polymers. Both An-CPOP-1 and An-CPOP-2 showed amorphous character, outstanding thermal stability, and high BET surface area (up to 1000 m2/g) with microporosity and mesoporosity architectures based on XRD, TGA analyses and N2 adsorption/desorption measurements. Interestingly, TEM and SEM images revealed that An-CPOP-1 had regular tubular nanotubes structure without using template or surfactant or carbonization at the elevated temperature. The as-prepared An-CPOP-2 exhibited a high specific capacitance of 98.4 F g−1 at a current density of 0.5 A g−1 and excellent cycling stability (95.3% capacitance retention over 2000 cycles), which could be used as good material for energy storage application.

In this study, films of perfluoro-functionalized poly(3,4-ethylenedioxythiophene) [poly(EDOT-F)] were prepared directly through electropolymerization for use as catalysts for the oxygen reduction reaction (ORR), applying the rotating ring disk electrode technique. Poly(EDOT-F) operated catalytically through a two-electron and/or mixed pathway. Spinel Co3O4 nanospheres were introduced into poly(EDOT-F) to enhance its ORR performance and electron transfer number (n). Benefiting from its unique interconnected pore structure and its resemblance to the binder Nafion, poly(EDOT-F) could be used as a single replacement for both the binder and the carbon support required for the spinel Co3O4 nanospheres. The Co3O4/poly(EDOT-F) composite, when used as an electrode, exhibited a limiting current density of −4.761 mA cm–2 at 0.18 V (vs RHE) (cf. 20% Pt/C: −3.615 mA cm–2), an onset potential of 0.99 V (cf. 20% Pt/C: 0.938 V), and a half-wave potential of 0.628 V (cf. 20% Pt/C: 0.727 V) in 0.1 M aqueous KOH. The electron transfer number of the Co3O4/poly(EDOT-F) nanocomposite in the ORR was 3.84, suggesting a desirable four-electron pathway. This high electrocatalytic activity presumably resulted from the synergistic effect of the Co3O4 nanospheres and the poly(EDOT-F) polymer, which created many more active sites, enhanced the electron transfer kinetics, and eventually improved the ORR performance.

We report three new β-ketoenamine-linked covalent organic frameworks (COFs) prepared through Schiff-base [3 + 3] polycondensations of 1,3,5-triformylphloroglucinol (TFP-3OHCHO) with three tris(aminophenyl)-presenting derivatives—featuring amino, carbazole, and pyridine units, respectively under solvothermal conditions. The resultant TFP-COFs possessed high BET specific surface area up to 686 m2 g–1 and excellent crystallinity, which showed excellent electrochemical specific capacitances (up to 291.1 F g–1) and CO2 uptake efficiency up to 200 mg g–1 at 273 K. We propose the enhanced performance in supercapacitor and gas storage is owing to the conjugated enamine structures with redox-active triphenyl amino, carbazole, and pyridine moieties. In addition, we further investigate the formation mechanism of the spherical TFP-TPA COF by studying the morphological changes over time. The presence of more highly planar monomer units in the hexagonal structures of the resultant COFs led to stronger quadrupolar interaction with the included CO2 molecules.

We report three new β-ketoenamine-linked covalent organic frameworks (COFs) prepared through Schiff-base [3 + 3] polycondensations of 1,3,5-triformylphloroglucinol (TFP-3OHCHO) with three tris(aminophenyl)-presenting derivatives—featuring amino, carbazole, and pyridine units, respectively under solvothermal conditions. The resultant TFP-COFs possessed high BET specific surface area up to 686 m2 g–1 and excellent crystallinity, which showed excellent electrochemical specific capacitances (up to 291.1 F g–1) and CO2 uptake efficiency up to 200 mg g–1 at 273 K. We propose the enhanced performance in supercapacitor and gas storage is owing to the conjugated enamine structures with redox-active triphenyl amino, carbazole, and pyridine moieties. In addition, we further investigate the formation mechanism of the spherical TFP-TPA COF by studying the morphological changes over time. The presence of more highly planar monomer units in the hexagonal structures of the resultant COFs led to stronger quadrupolar interaction with the included CO2 molecules.