Rational design of donor-acceptor conjugated polymers with high performance on peroxydisulfate activation for pollutants degradation

Polymeric carbon nitride (PCN) has great potential for peroxydisulfate (PDS) activation but still challenge due to the sluggish electron-hole pair dissociation and tardy charge transfer dynamics. Herein, a novel PCN-based donor-acceptor conjugated polymer (PCN/4-MI D-A) is synthesized by copolymerization of urea and 4-methoxyphenyl isothiocyanate. The obtained PCN/4-MI D-A exhibited significantly improved activity on PDS activation for nitenpyram (NTP) degradation under visible light. As a result, PDS+PCN/4-MI75 shows the highest kinetic constants (0.115 min−1), which is ~6.8 times as that of the pure PCN. Density functional theory (DFT) calculations indicated that 4-methoxyphenyl as an electron-donating group promotes the charge separation/transfer of PCN/4-MI D-A. In addition, the PCN/4-MI D-A is more conducive to the PDS adsorption at the position where the amino group linked with 4-MI. The PCN/4-MI D-A generated abundant electrons which were subsequently transferred to the PDS by tunneling effect. This study provides a new design concept for the highly efficient PDS activation by constructed PCN-based donor-acceptor conjugated polymers.