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

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 alpha-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 alpha-Fe2O3 spherical nanoparticles having the dimension of 50-100 nm. The designed g-C3N4@alpha-Fe2O3 heterostructure exhibit better photodegradation towards methyl orange under visible light exposure than pristine alpha-Fe2O3 with pseudo-first-order kinetics. The pseudo-first-order kinetic rate constant (k) for alpha-Fe2O3, and g-C3N4@alpha-Fe2O3, was determined to be 0.0171 min(-1) and 0.02899 min(-1), respectively. The g-C3N4@alpha-Fe2O3 exhibited greater photocurrent density than that of the alpha-Fe2O3 sample under simulated solar irradiance. In comparison with pristine alpha-Fe2O3 (83%), S-scheme g-C3N4@alpha-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@alpha-Fe2O3 was discussed and found that O-2(center dot-) radicals participate a major function in the photodegradation of methyl orange dye, followed by center dot OH- radicals. The designed g-C3N4 decorated alpha-Fe2O3 heterostructure may be a possible material for the treatment of textile effluents.

Automated summary

In this investigation, a g-C3N4@alpha-Fe2O3 heterostructure was synthesized and found to exhibit better photodegradation efficiency towards methyl orange under visible light exposure compared to pristine alpha-Fe2O3. The designed heterostructure demonstrated enhanced photocurrent density and improved photodegradation efficiency due to narrow bandgap energy, enhanced charged transportation, and reduced charges recombination achieved through engineered heterostructure.