Deposition of dyes on Cobalt-based metal-organic framework (Co-MOF) composites with promoted achievement photocatalytic degradation of an anionic dye (EBT) under visible light irradiation

ABSTRACT

In this study, porous cobalt-based organic frameworks (Co-MOF) were facilely synthesised and functionalised with the amino group using 1, 4-diazabicyclo [2.2.2] octane (DABCO) as a linker. After that, Co-MOF was encapsulated with photosensitive dyes such as methylene blue (MB) and methyl orange (MO) to form MB@Co-MOF and MO@Co-MOF composites. The prepared photocatalysts were fully characterised to evaluate their crystal structure, catalytic properties and morphology. The prepared composites were evaluated towards the photodegradation of Erichrome Black-T dye (EBT) as an example of azo dyes under visible light compared with Co-MOF photocatalyst. The photocatalytic efficiency was 78.9%, 92.0% and 99.7% using 100 mg/L of EBT and photodegradation rate constants (K₁) ranged from 0.02, 0.05 and 0.08 min⁻¹at 240 min of visible light irradiation using Co-MOF, MO@Co-MOF and MB@Co-MOF, respectively. This indicates the importance of using photosensitive azo-dyes in this study (e.g. MB and MO) for enhanced the photodegradation of wastewater pollutants. The results demonstrate that MB@Co-MOF photocatalyst is the most prominent photocatalyst for in situ degradation of anionic dyes (e.g. EBT) from wastewater with the highest photostability up to five cycles.

KEYWORDS:

• CoMOF
• methylene blue
• erichrome Black-T
• dyes pollutants
• wastewater treatment
• visible light photodegradation

Acknowledgments

I sincerely thank the director of the Egyptian Petroleum Research Institute and the director of central laboratories and all the staff members for rendering their help and facilitating the analysis and characterization process.

Disclosure statement

There is no competing interests. No potential conflict of interest was reported by the author(s).