Facile sonochemical synthesis and characterization of amino acid-based metal-organic frameworks for enhanced dye adsorption

Day by day, an incredible rise has been noticed in industrial development which led to many environmental issues, one of which is water pollution. As a result, removal of hazardous dyes, organic contaminants and toxic heavy metals from wastewater is gaining major concern to eliminate the negative effects on the life. For this purpose, a new class of porous materials, metal organic framework (MOFs) have attracted attention of researchers as these materials exhibit excellent characteristics for the adsorptive removal of environmental contaminants. In this study, a series of metal organic frameworks, L-Glu-Zn, L-Glu-Mn & L-Glu-Cu, based on amino acid have been successfully synthesized by ultra-sonicator green synthesis method. A naturally occurring amino acid, L-Glutamic acid was used as an organic linker and acetate salts of metals (Zn, Cu, Mn) were used in construction of MOFs. All the newly synthesized compounds have been characterized by FTIR, PXRD, FE-SEM, BET surface analysis, TGA techniques. Specific surface areas of synthesized L-Glu-Mn, L-Glu-Cu, and L-Glu-Zn were measured by BET analysis respectively as 242.6 m2/g, 109.6 m2/g, 76.4 m2/g. Using the synthetic materials, an adsorptive removal of xylenol orange dye was investigated as possible use in water treatment. The Langmuir isotherm was seen to fit well to adsorption data obtained for all three adsorbent materials studied, and adsorption processes followed the pseudo-first order kinetics. Thus, this study enlights the use of MOFs as adsorbents in water treatment.