Tetraphenyl-p-phenylenediamine-based tunable conjugated microporous polymers: Adsorption and photodegradation of hazardous dyestuff in aqueous environments

In this work, a series of donor-acceptor type tetraphenyl-p-phenylenediamine-based CMPs (TPPDA CMPs) is developed using the Suzuki-coupling reaction for dual photocatalysis and adsorption of rhodamine B (RhB) dyestuff. The boronic ester of tetraphenyl-p-phenylenediamine (TPPDA-4Bor) considers as a donor, and the acceptors are pyrene (Py), tetrabenzophenazine (TBP), and triphenyltriazine (TPT). The resultant D-A TPPDA CMPs show high surface areas of up to 1430 m2 g-1 and high thermal stabilities (Td10: 546 degrees C, char yield up to 74.5 %), in addition to remarkable photophysical properties such as small band gaps of up to 2.11 eV. In addition, the TTPDA-Py CMP provide an outstanding adsorption capacity of up to 1587 mg g-1 toward RhB dyestuff at room temperature, outperforming that of previously reported materials. Furthermore, TPPDA-Py CMP show the highest photocatalytic degradation of RhB dyestuff with the highest efficiency of up to 99 %, and a reaction rate constant of up to 3.3 x 10-2 min-1. Even after multiple cycles, TPPDA CMPs demonstrate excellent reusability in both the adsorption and photodegradation of RhB molecules exhibiting the premium stability. Thus, we believe that our study can pave the way for the efficient design of D-A CMPs based on the TPPDA unit as an exciting photocatalyst for a diversity of photocatalytic applications.