Preparation of novel diperylene-cored polyimide photocatalyst with broad-spectra response and high stability

A novel polyimide (PI) with broad-spectra response, high photocatalytic activity and stability under super acidic conditions (pH = 0) was synthesized via polymerizing method. Two types of perylene-cored mate -rials (PDIAN and PTCDA) with anhydride and diamine respectively, were applied as precursors for PI poly-merization. The as-prepared PI was optimized at 1:1 initial molar ratio of PDIAN to PTCDA. Using common PI (synthesized from melamine and pyromellitic dianhydride) as comparison, the Cr(VI) reduc-tion rate was boosted from 25.4% to 96.6% within 120 min light irradiation. The corresponding rate con-stant by PI(PDIAN/PTCDA) was estimated to be ca. 11.7 times relative to that by common PI. The boosted performance was ascribed to the strong p -p conjugation from diperylene cores, which can decrease the photoluminescence intensity and electrochemical impedance, so as to promote the separation and transfer of photogenerated electron-hole pairs. In addition, the optimized PI(PDIAN/PTCDA) displayed wide-spectra response, which can still work under 730 nm light. The influencing factors toward Cr(VI) reduction were also clarified to be beneficial at lower pH and increased concentration of hole scavenger. After five cycles at pH 0, the PI still maintained excellent redox activity and structural stability.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

A novel polyimide (PI) with broad-spectrum response, high photocatalytic activity, and stability under super acidic conditions was synthesized. The performance of the optimized PI (PDIAN/PTCDA) was significantly enhanced compared to the common PI, with a Cr(VI) reduction rate of 96.6% within 120 min light irradiation. The boosted performance was attributed to the strong p-p conjugation from diperylene cores, which promoted the separation and transfer of photogenerated electron-hole pairs.