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

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, stable, environmentally friendly, and highly effective photocatalyst for the treatment of various organic pollutants under visible light irradiation.

Automated summary

A novel and stable composite material was successfully synthesized and its structural and morphological properties were investigated. The composite exhibited higher light absorption and charge separation capabilities under visible light irradiation, resulting in significant photocatalytic degradation of methylene blue. The composite also maintained its activity after multiple cycles.