Microwave melting rapid synthesis of CQDs/PpPD heterojunctions with efficient microwave electrodeless lamp photocatalytic performance

A sheet-like carbon quantum dots/poly-p-phenylenediamine (CQDs/PpPD) nanophotocatalyst with sta-ble structure and excellent photocatalytic performance was prepared by a microwave melting method using glucose and p-phenylenediamine as raw materials. The structures of CQDs/PpPD were character-ized by X-ray diffraction, Fourier transform infrared spectrometer, X-ray photoelectron spectrometer, scanning electron microscope, and transmission electron microscope. The results showed that the as-prepared nanophotocatalyst was a stable composite structure with sheet-like PpPD as the main body and spherical CQDs of 2.0-5.0 nm evenly distributed on its surface. Combined with the valence band spectrum of X-ray photoelectron spectrometer, Diffuse reflectance spectra, and photoluminescence characterization analysis, the structure of CQDs/PpPD was determined to be a type II heterojunction, which confirmed that CQDs/PpPD is an excellent photocatalyst material with stronger light absorption capacity and greater electron-hole pair separation efficiency. The photocatalytic performance of CQDs/ PpPD was investigated in the microwave electrodeless lamp photocatalytic system. The results showed that microwave could greatly improve the photocatalytic performance of CQDs/PpPD, which could degrade 91.8% of 50 ppm rhodamine B within 10 min, and its degradation efficiency was more than twice that of P25. After four cycles of degradation experiments, the degradation rate remained stable above 88.0%. The photocatalytic mechanism of CQDs/PpPD was discussed through active species detection experiments, combined with the structure and performance characteristics of the materials. Taking into consideration the results obtained from this work, CQDs/PpPD prepared by the microwave melting method is a potential high-efficiency photocatalytic material.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

In this study, a stable sheet-like carbon quantum dots/poly-p-phenylenediamine (CQDs/PpPD) nanophotocatalyst with excellent photocatalytic performance was prepared using glucose and p-phenylenediamine as raw materials via a microwave melting method. The as-prepared CQDs/PpPD exhibited a stable composite structure with spherical CQDs of 2.0-5.0 nm evenly distributed on the surface of sheet-like PpPD. The photocatalytic performance of CQDs/PpPD was significantly improved, achieving a degradation efficiency of 91.8% for 50 ppm rhodamine B within 10 minutes.