Investigation on photocatalytic activity of g-C3N4 decorated α-Fe2O3 nanostructure synthesized by hydrothermal method for the visible-light assisted degradation of organic pollutant

Abstract

In recent decades, heterostructured photocatalysts have gained the great interest for their ability to possess higher photocatalytic activity. In this investigation, we synthesized g-C3N4 decorated α-Fe2O3 nanostructure by hydrothermal method to develop heterostructure. XRD, SEM, TEM, UV-DRS characterizations on the prepared sample revealed that g-C3N4 nanoparticles with 5–10 nm were decorated on the surface of the α-Fe2O3 spherical nanoparticles having the dimension of 50–100 nm. The designed g-C3N4@α-Fe3O4 heterostructure exhibit better photodegradation towards methyl orange under visible light exposure than pristine α-Fe2O3 with pseudo-first-order kinetics. The pseudo-first-order kinetic rate constant (k) for α-Fe2O3, and g-C3N4@α-Fe2O3, was determined to be 0.0171 min−1 and 0.02899 min−1, respectively. The g-C3N4@α-Fe2O3 exhibited greater photocurrent density than that of the α-Fe2O3 sample under simulated solar irradiance. In comparison with pristine α-Fe2O3 (83%), S-scheme g-C3N4@α-Fe2O3 heterostructure exhibited higher photodegradation efficiency (94%) since it had narrow bandgap energy, enhanced charged transportation, and reduced charges recombination owing to engineered heterostructure. The mechanism for the improved photodegradation efficiency of g-C3N4@α-Fe2O3 was discussed and found that O2– radicals participate a major function in the photodegradation of methyl orange dye, followed by OH− radicals. The designed g-C3N4 decorated α-Fe2O3 heterostructure may be a possible material for the treatment of textile effluents.