ZnO/carbon quantum dots nanocomposites: one-step fabrication and superior photocatalytic ability for toxic gas degradation under visible light at room temperature

ZnO/carbon quantum dots (ZnO/CQDs) nanocomposites were prepared by a one-step hydrothermal reaction and used as superior photocatalysts for the degradation of toxic gas (benzene and methanol) under visible light at room temperature. The as-prepared ZnO/CQDs nanocomposites were characterized by X-ray powder diffraction, Raman spectra, Fourier transform infrared spectroscopy, UV-Vis absorption spectroscopy, scanning and transmission electron microscopy. The results show that these nanocomposites exhibit higher photocatalytic activity (degradation efficiency over 80%, 24 h) compared to N doped TiO2 and pure ZnO nanoparticles under visible light irradiation. In the present catalyst system, the crucial roles of CQDs in the enhancement of photocatalytic activity of the ZnO/CQDs nanocomposites are illustrated.