Synergistic impacts of composite formation and doping techniques to boost the photocatalytic aptitude of the BiFeO3 nanostructure

Abstract Reduced graphene oxide (rGO)-based rare-earth-doped metal oxide nanocomposites have shown exceptional photocatalytic efficiency for water splitting and remediation. In this study, we used a simple wet chemical technique to create gadolinium (Gd) doped bismuth ferrite (BiFeO3) nanoparticles, which we then grafted onto an rGO using an ultrasonication strategy to create the nanocomposite (Gd-doped BiFeO3/rGO). The photocatalytic properties of the Gd-doped BiFeO3/rGO composite as produced were studied and compared to those of pure BiFeO3 and Gd-doped BiFeO3. The photocatalytic capabilities of the three synthesized materials were tested by determining their effectiveness in removing methylene blue dye (MBD) from an aqueous solution at the expanse of solar irradiation. The Gd-doped BiFeO3/rGO showed notable photocatalytic efficiency compared to bare BiFeO3 and Gd-doped BiFeO3 samples. Specifically, the Gd-doped BiFeO3/rGO photocatalyst removed 87% MB dye (rate constant ∼ 0.016 min−1) after solar irradiation for 120 min, whereas the pure BiFeO3 and Gd-doped BiFeO3 samples degraded only 55% (rate constant ∼ 0.003 min−1) and 66% (rate constant ∼ 0.008 min−1) MB, respectively under the same conditions. The rGO based nanocomposite demonstrated excellent transient photocurrent response, which was 11-fold and 2.98-fold larger than pristine BiFeO3 and Gd-doped BiFeO3, respectively. The increased photocatalytic activity of rGO-based photocatalysts may be attributed to the synergistic impact of Gd doping and rGO nanosheets inclusion, which results in a redshift in light absorption. Employed strategies suppressed electron-hole re-combination and charge-transfer resistance but boosted the electronic conductivity (due to the existence of conjugated -electrons) and diffusive properties (due to nanoarchitecture). Such an effective Gd-doped BiFeO3/rGO nanocomposite may give rise to novel pathways for achieving visible light response photocatalysts.