Synthesis of Mixed Ligand 3D Cobalt MOF: Smart Responsiveness towards Photocatalytic Dye Degradation in Environmental Contaminants

• A new 3D MOF {[Co 3 (BTC) 2 (Bimb) 2.5 ]∙2H 2 O} n, was constructed to employ as photocatalyst in catalytic degradation of a series of aromatic cationic, neutral and anionic dyes. • The photodegradation efficiency of Co(II)-MOF was found to be maximum for Fluorescein (91.7%) and lowest for Congo Red (15.8 %). • The unique structural properties and kinetics studies suggest its imminent claim as catalyst towards the degradation of organic aromatic dyes from the waste water. • The reported MOF was established to act as future material for purification of waste water contaminated with hazardous organic pollutant. A new metal organic framework {[Co 3 (BTC) 2 (Bimb) 2.5 ] · 2H 2 O} n (1) (Bimb = 1,4-bis[(1H-imidazol-1-yl)methyl]benzene and H 3 BTC = 1,3,5-Benzenetricarboxylic acid) has been synthesized and structurally characterized by elemental analysis, single-crystal X-ray diffraction (SC-XRD), vary temperature powder X-ray diffraction (VT-PXRD) and vary temperature Fourier transform infrared spectroscopy (VT-FTIR) have been used to establish the complex (1) and its physico-chemical analysis.. According to single crystal structure analysis, complex (1) features a three-dimensional network made up of trinuclear cobalt constructed by two-dimensional layer supported by BTC 3− and Bimb ligands. Variable temperature luminescence relationship of as-prepared and excited form of complex (1) investigated luminescence emission in the region of 441-461 nm (2.81-2.69 eV) at room temperature with little difference in physical facade. Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDAX), VT-PXRD and VT-FTIR studies revealed globular shaped Co 3 O 4 nanoparticles with average sizes of about 20 nm as a result of thermal breakdown of (1) . The photocatalytic experiments revealed that complex (1) displayed efficient photocatalytic capabilities to decompose the Fluorescein, Eriochrome Black T, Methyl Violet, Crystal Violet, Methyl Orange, Rhodamine B, Methylene Blue, Rhodamine 6G, Neutral Red and Congo Red under UV light irradiation. The photodegradation of FS, EBT, MV, CV, MO, RhB, MB, Rh6G, NR and CR exposed to be 91.7, 77.5, 68.7, 53.9, 50.9, 50.8, 47.4, 38.1, 19.5 and 15.8 %, respectively, after 135 minutes of irradiation with as-prepared MOF (1) .