Fabrication of CoFe2O4/sulphonated graphene oxide antibacterial nanohybrid and evaluation of its enhanced photocatalytic activity, mechanism and pathway of degradation of textile dyes

Abstract

Sulfonated graphene oxide (SGO) supported cobalt ferrite photocatalyst of different compositions were prepared via in-situ co-precipitation method. The nanocomposite was characterized by XRD, SEM, TEM, Raman, VSM, XPS, UV-DRS and BET. The experimental results showed that nanocomposite having molar compositions Co2+ = 0.05 M, Fe3+ = 0.1 M and SGO = 0.15 g (8 wt%) exhibited excellent photocatalytic and adsorption efficiency in removal of methylene blue (MB), methyl orange (MO) and methyl red (MR) dyes. The composite effectively degrades textile effluents and the water quality has significantly increased after treating with the catalyst. The dye degradation reactions were carried out under presence and absence of visible light illumination as well as H2O2. Without light irradiation, decolourization of the dyes was observed which suggests the presence of adsorptive behaviour of the prepared catalysts. Kinetic study reveals that the adsorption is pseudo-second order in nature and fits to Langmuir isotherm while photocatalytic degradation follows pseudo-first order kinetics and fits to Langmuir-Hinshelwood model. Under light illumination, 96.44 %, 98.98 % and 95.06 % of MB, MO and MR was degraded within 30, 40 and 35 min. The effect of pH, catalyst dose, concentration of H2O2, presence of anions, cations and scavengers has been explored. The photocatalyst also shows superior antibacterial property against E. coli and S. aureus bacterial strains.