Insight into the novel ZIF-8@ N-CQDs/ZIF-67 nanocomposite for photocatalytic degradation of methylene blue under visible light irradiation

摘要: A novel and stable composite of ZIF-8@N-CQDs/ZIF-67 was synthesized using simple solvothermal methods. The structural and morphological properties of the composite were investigated using different techniques. The ability of N-CQDs to improve the photocatalytic activity of ZIF-8@ZIF-67 for the photodegradation of methylene blue (MB) using visible and solar light was tested. The composite exhibited higher light adsorption and charge separation capabilities than N-CQDs and ZIF-8@ZIF-67. The degradation % of 32.0 ppm MB under visible light irradiation reached 94.0 % after 180 min, and the composite maintained its photoactivity after four cycles with a minimal decrease in the degradation efficiency. Scavenging tests indicated that the free electrons (superoxide radicals) played a major role in the photodegradation of MB, which is followed by hydroxyl radicals and holes. Therefore, this work provides a new …