Donor‐Acceptor Conjugated Heptazine Polymers with Highly Efficient Photocatalytic Degradations towards Tetracyclines

Abstract

Photocatalysis is an efficient and green technology in the environmental protection. Due to the high charge separation and transfer, donor-acceptor (D-A) conjugated polymers attract much attention for their photocatalytic degradations towards organic pollutants. Herein, the authors reported three novel D-A conjugated polymers, named as HPBP, HPTP, and HPF, with heptazine moieties as electron acceptors, while biphenyl, terphenyl, or fluorene moieties as electron donors, respectively, which indeed exhibit a highly efficient photocatalytic degradation towards tetracyclines upon the visible-light irradiation. Among them, the photocatalytic performance of HPF is especially noticeable with the degradation rate up to 87% within 30 min, almost 11 times in comparison to those of pristine g-C 3 N 4 , which is mainly attributed to its high crystallinity and conjugation. For their photocatalytic mechanism, the •O 2 radical anions are regarded as the active species.

Boosting Exciton Dissociation and Charge Transfer in Triazole-Based Covalent Organic Frameworks by Increasing the Donor Unit from One to Two for the Efficient Photocatalytic Elimination of Emerging Contaminants

“…The photocatalytic degradation performances toward TC (10 mg/L, one type of emerging organic contaminant) by two obtained D–A COFs under visible-light irradiation were investigated. g-C 3 N 4 , a typical D–A polymeric photocatalyst, was employed as a comparison. Under dark conditions, negligible TC was adsorbed by these photocatalysts (Figure a).…”

Calix[4]arene‐Derived 2D Covalent Organic Framework with an Electron Donor–Acceptor Structure: A Visible‐Light–Driven Photocatalyst

“…The transient‐state photocurrent response of COF‐C4A‐BTD and g‐C 3 N 4 , a representative D–A polymeric conjugated photocatalyst, [ 21 ] was tested under repeated cycles of visible‐light irradiation and intermittent switching illuminations. As shown in Figure 4e, COF‐C4A‐BTD exhibited a significantly enhanced visible photocurrent response compared to g‐C 3 N 4 , indicating its superior photogenerated charge carrier separation efficiency.…”

Green Synthesis of Carbon Nitride‐Based Conjugated Copolymer for Efficient Photocatalytic Degradation of Tetracycline

“…High‐resolution C 1s XPS spectra are assigned to four bands at 284.6, 286.1, 288.0, and 288.6 eV (Figure 4c), ascribed to CC, CO, C═N, and C═O, respectively. [ 46 ] The bands at 398.2 and 399.7 eV in high‐resolution N 1s XPS spectra (Figure 4d) are curve‐fitted into C═N–C in triazine ring and N–C═O in amide bond, respectively. [ 47 ] As for high‐resolution O 1s XPS spectra, the bands at 531.2 and 532.6 eV are attributed to C–O and C═O, respectively (Figure S1, Supporting Information).…”