In situ assembly of CQDs/Bi2WO6 for highly efficient photocatalytic degradation of VOCs under visible light

Abstract

A series of carbon quantum dot (CQD)/Bi₂WO₆ hybrid materials were synthesized via a facile in situ hydrothermal method, where the CQDs were prepared using different carbon sources. As demonstrated by multiple techniques, including XRD, SEM, TEM, XPS, BET, UV-vis, FT-IR, PL and TPR, the visible light absorption wavelength red-shifted, the oxidation ability was enhanced, and the recombination probability of electron–hole pairs was inhibited by incorporating the CQDs in Bi₂WO₆. Moreover, different carbon source-derived CQD/Bi₂WO₆ materials exhibited different optical and electronic properties. The CQD/Bi₂WO₆ materials exhibited excellent activity in the photocatalytic degradation of VOCs under visible light irradiation, among which the CQDs/Bi₂WO₆ derived from chitosan demonstrated the best activity with 96.9% degradation for gaseous toluene and 97.1% for gaseous formaldehyde within only 120 min. Furthermore, the CQDs/Bi₂WO₆ showed high stability and reusability.