Morphological and Structural Elucidation of Room Temperature Catalytic Degradation of Amoxicillin Antibiotic Using Zinc Porphyrin Metal Organic Framework

Abstract

Environment is witnessing an extensive increase in persistent and bioactive micro pollutants from the last few decades. Since most clinical modalities are flooded with antibiotics, environmental samples such as sewage treatment effluents, surface water and secondary water drainage etc. reveal the presence of bio-recalcitrant antibiotics worldwide, ergo there is a spurring rise in antibiotic resistant microorganisms. In order to circumvent the escalating concentration of amoxicillin (microgram/liter) we contrived a potential metal organic framework (MOF) and lab tested it for catalytic functionality. A zinc-porphyrin MOF using Tetra (4-carboxyphenyl) porphyrin H2TCPP (>97%) as a ligand and Zinc acetate as a metal salt was solvo-thermally synthesized. The morphological and structural characterization were performed using FESEM, XRD, EDAX, FTIR and UV-Visible spectroscopy. The fabricated MOF catalyst exhibits sterling ability of amoxicillin degradation in a dark environment at room temperature, accounting a degradation efficiency of about 97.3% in a 0.1 mg/ml concentration. 90 minutes of catalyst exposure to the antibiotic shows maximum degradation after which there is no further change in amoxicillin concentration. First time we have exploited electrochemical cyclic voltametric (CV) measurement to monitor the degradation process which was validated by FTIR recording, and noticed that the degradation process followed a first order kinetics. We have also discussed the morphological stability of the fabricated Zn porphyrin MOF after antibiotic exposure and reported a comparative outline between catalytic efficiency of different MOF species. High porosity and effective charge transfer between carboxyphenyl) porphyrin ligand to vacant d orbital of Zn+2 are pivotal factors for effective sorption and degradation of amoxicillin antibiotics dark at room temperature. We would expect the developed Zn porphyrin MOF is very promising for successful commercial application due to its energy efficiency (dark) and simple process for effective degradation of antibiotics.