Triphenylamine-Anthracene-Based Conjugated Microporous Polymers for the Detection and Photocatalytic Degradation of Organic Micropollutants

Triphenylamine (TPA)-anthracene (AN)-based conjugatedmicroporouspolymers (CMPs), namely PTPA-AN-9,10 and PTPA-AN-2,6, were synthesized by the Suzuki-Miyaura cross-coupling reactionof tris(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-aminewith 9,10-dibromoanthracene and 2,6-dibromoanthracene, respectively.The as-synthesized polymers exhibited cauliflower-like nanoscale morphology, high Brunauer-Emmett-Teller surface area of 362 m(2)/g, and thermal stability up to 458 & DEG;C in the case of PTPA-AN-2,6. Interestingly, PTPA-AN-9,10 showedbright cyan fluorescence in tetrahydrofuran dispersion and exhibitedfluorescence-based sensing of various nitroaromatics, where 2,4,6-trinitrophenolexhibited the lowest limit of detection of 34 & mu;M and the highestStern-Volmer constant (K (SV)) of5.8 x 10(3) L mol(-1). On the otherhand, PTPA-AN-2,6 showed efficient photocatalytic reductionof various nitroaromatic micropollutants such as p-nitrophenol (p-NP) (k = 0.164min(-1) and turnover frequency (TOF) = 0.769 h(-1)) and degradation of Congo red from water with ultrafastkinetics (k = 0.047 min(-1) and TOF= 0.024 h(-1)) which are much better than most ofthe previously reported CMPs. These polymers were recovered usingsimple filtration and were recycled four to five times without losingtheir catalytic efficiency significantly for p-NPreduction as well as dye degradation. In general, TPA-based CMPs havebeen used as efficient multitasking materials for the sensing of nitroaromaticmicropollutants and photocatalytic degradation of Congo red dye aswell as p-NP to its value-added product p-aminophenol.

Automated summary

Triphenylamine (TPA)-anthracene (AN)-based conjugated microporous polymers (CMPs) with bright cyan fluorescence in tetrahydrofuran dispersion were synthesized by Suzuki-Miyaura cross-coupling reaction. These polymers exhibited high surface area, thermal stability, as well as fluorescence-based sensing of nitroaromatics and photocatalytic reduction of nitroaromatic micropollutants. The polymers also showed good recyclability without significant loss of catalytic efficiency.