Metal Organic Framework (KIUB-MOF-1) as efficient adsorbent for cationic and anionic dyes from brackish water

• A novel cobalt based metal organic framework named KIUB MOF-1 was synthesized successfully. • KIUB MOF-1 effectively removes cationic and anionic dyes from brackish water. • Adsorption mechanism was also discussed. • Hydrogen bonding and electrostatic interaction were responsible for the adsorption of dyes with KIUB MOF-1. Cobalt MOF with morpholine named as KIUB-MOF-1 (KIUB stand for Khalil The Islamia University of Bahawalpur) was successfully synthesized by using simple method in excellent yield and characterized by using FTIR, SEM, BET and XRD. From the characterization it was confirmed that this MOF contains highly porous structure and can be applied for adsorptive elimination of contaminants. Elimination of cationic and anionic dyes followed chemisorption mechanism and monolayer adsorption as confirmed by kinetic parameters. Electrostatic and hydrogen bonding are responsible for elimination of dyes and maximum adsorption capacity was 15,610, 14,721 and 5083 mg/g for anionic (methyl orange) and cationic (methylene blue and malachite green) dyes respectively. According to literature this is the first study to remove organic dyes from brackish water using diethylene oximide (morpholine) based MOF. Adsorption mechanism of IUB-MOF-1 illustrated diagrammatically in which dyes are adsorbed with MOF with electrostatic interactions and hydrogen bonding.