Unraveling the synergy between oxygen doping and embedding Fe nanoparticles in gC3N4 towards enhanced photocatalytic rates.

[Display omitted] • gC 3 N 4 nanosheets was incorporated with O anions and Fe metallic nanoparticles by a facile method. • Hybridization between Fe, N and O leads to the formation of an intermediate band within the bandgap of gC 3 N 4. • Exfoliation strategy by mixed acid treatment increased the surface area by one order of magnitude than pristine gC 3 N 4. • Cointegration of these strategies led to ∼17 times improvement in the photocatalytic rate. • Combined experimental and theoretical approach provides concrete evidence for improvement in all intrinsic properties. With graphitic carbon nitride (gC 3 N 4) showing considerable potential for photocatalytic applications, the four significant limitations: surface area, light-harvesting capability, photogenerated charge separation, and charge transfer at the interface, need to be comprehensively addressed. The present work aims to exfoliate the gC 3 N 4 stacking layers and fragment the layers horizontally to form ultra-thin nanosheets (NS) by a facile mixed-acid treatment. The surface area of gC 3 N 4 increased by one order of magnitude (120 m2/g), due to the formation of nanosheets with planar size below ∼50 nm. Moreover, incorporating non-metal (oxygen) anion dopants and metal (iron) nanoparticles enhances the overall reactivity of gC 3 N 4 NS under light irradiation. Co-integration of these strategies led to ∼17 times improvement in the photocatalytic pollutants degradation rate compared to pristine gC 3 N 4. First-principles calculations and experimental evidence suggest the formation of an intermediate band within the bandgap of gC 3 N 4 , caused by the hybridization of N -Fe-O, which assists in harvesting a larger number of photons. Nanosheet morphology provides a shorter distance to photogenerated charges towards the surface, while the incorporation of Fe and O together offers the lowest charge transfer resistance at the interface to efficiently degrade the adsorbed pollutant molecules on the surface. With all these promoting features along with cost-effective and stable elements, Fe-O-gC 3 N 4 NS provides an ideal solution for tuning the intrinsic morphological and electronic structure of gC 3 N 4 for its effective application in various photocatalytic reactions. [ABSTRACT FROM AUTHOR]