In-Situ Construction of GO/MIL-100 (Fe) Polyhedrons for Adsorption of Congo Red Dye from Aqueous Solutions and its Biological Activities

In this study, the GO/MIL-100 (Fe) was constructed and its efficacy was evaluated to adsorb Congo Red (CR) dye and disinfect the microorganisms. The characterization of the fabricated material was performed using FE-SEM, EDX, PXRD, Raman, FTIR, TG, and BET analyses. The crystallite size of GO/MIL-100 (Fe) was measured with Debye–Scherrer’s formula as 4.57 nm. Moreover, the investigations verified that the GO/MIL-100 (Fe) produced exhibited a significantly high BET surface area of 991 m²/g and a polyhedron structure. The efficiency of the GO/MIL-100 (Fe) composite in the elimination of CR was examined by considering the impact of pH, GO/MIL-100 (Fe) dose, dye concentrations, and contact time. The finding indicated that the best efficacy of the GO/MIL-100 (Fe) occurred at pH = 2, dose = 20 mg, dye concentration = 50 mg/L, and contact time = 90 min for CR. The regression coefficient value (R² = 0.9642) indicates that the pseudo-first-order model is an appropriate model for the adsorption process, and it suggests that the adsorption process is of a physical nature. The Sips model fitted better to the adsorption isotherms, R² = 0.9980, with a maximum adsorption capacity of 119.54 mg/g. The adsorption capacity of CR in the existence of other ions followed the order Cl⁻ > NO₃⁻ > SO₄²⁻ > HCO₃⁻. Based on the disc diffusion method the inhibition zones of GO/MIL-100 (Fe) toward E. coli and S. aureus were obtained to be 11.2 and 14.5 mm, respectively.