Anti-bacterial and arsenic remediation insights in aqueous systems onto heterogeneous metal oxide (CuAlFeO)/rGO hybrid: an approach towards airborne microbial degradation.

Copper-based ternary metal oxide (i.e., Cu0.52Al0.01Fe0.47O4) impregnated reduced graphene oxide nanohybrid is verified for microbial and arsenic treatment. Growth inhibition of colonies are observed around 99.99% (E. coli), and 99.83% (S. aureus) at 10-20 μg/mL of hybrid dosage, respectively. The inhibition rates for both the colonies are increased to 99.9998% at 80 μg/mL. TEM images have shown insight of cell-content/lipid leakage behavior after inoculating with the hybrid. The efficient hindrance towards microbial colony growth is attributed to better charge transfer, reactive oxygen species generation, and metal-ion release. Maximum arsenic sorption capacities are observed around 248 and 314 mg/g for As(III), and As(V), respectively (C ~ 500 ppm). Surface morphology studies onto arsenic adsorption are reported with atomic force microscope, and FT-IR/Raman analysis. A detailed discussion onto individual spectra of As 3d spectra confirmed the occurrence of redox transformation in arsenic species [As(III)]. The variation in the quantity (at. %) of oxygen functional groups in O1s spectra (i.e., M-O, M-OH, and -OH) onto the hybrid supported the ligand-exchange behavior. Cyclic voltammetry study in arsenic electrolytes (10 µM - 1 mM) provides the occurrence of various in-situ electrochemical reactions supporting the redox activity. A significant electromagnetic wave absorption characteristics of the present hybrid is proposed with plausible airborne antimicrobial-agent abilities.