Engineering Redox Activity in Conjugated Microporous Polytriphenylamine Networks Using Pyridyl Building Blocks toward Efficient Supercapacitors.

Nitrogen-rich conjugated microporous polymers (CMPs) with tunable porosities and reversible redox properties have received increasing interest as electrode materials for supercapacitors. Herein, pyridyl building blocks with different substitutions are selected to synthesize four amine-linked conjugated microporous polytriphenylamine (PTPA) networks via Buchwald-Hartwig cross-coupling reaction engineering the redox activity of PTPAs. The structures, porosities, and redox activities of these four PTPAs are investigated. The electrochemical characterization results show that PTPA obtained using 2,5-diaminopyridine dihydrochloride (i.e., PTPA-25) displays the highest specific capacitances up to 335 F g-1 in 1.0 m H2 SO4 at a current density of 0.5 A g-1 . Upon 5000 cycles, PTPA-25 maintains good initial capacitances up to 65%, nearly 100% Coulombic efficiencies at a current density of 2 A g-1 , and high rate properties (remained a high capacitance of 250 F g-1 at 10 A g-1 ). The influence of different substitutions of pyridyl on the redox activities of the synthesized PTPA electrodes is further proposed, which would give insight into engineering the performance of CMPs-based supercapacitors.