Fabrication of visible light-responsive dual Z-Scheme (α-Fe2O3/CdS/g-C3N4) ternary nanocomposites for enhanced photocatalytic performance and adsorption study in aqueous suspension

Abstract

We report dual Z-Scheme-derived photocatalysts to increae photocatalytic efficiency towards the degradation of organic pollutants in aqueous suspension with atmospheric oxygen under visible light irradiation. A ternary nanocomposite FCG (α-Fe2O3/CdS/g-C3N4) have been synthesized through the hydrothermal route via a solid-state method, which was characterized by XRD (X-ray diffraction), SEM (scanning electron microscopy), FT-IR (Fourier transforms IR spectroscopy), DRS (UV–vis diffuse reflectance spectroscopy), and XPS (X-ray photoelectron spectroscopy). The absorption edge of FCG ternary nanocomposites showed a bathochromic shift as paralleled to the pure CdS, α-Fe2O3, g-C3N4, and CdS/g-C3N4 (binary nanocomposite). The photocatalyst 5 wt% α-Fe2O3/CdS/g-C3N4 ternary nanocomposite (5 wt% FCG) showed substantial photocatalytic performance towards methylene blue (MB) and rhodamine B (RhB) dye degradation in aqueous suspension using visible light irradiation. The improved photocatalytic response may be accredited to sustained charge separation ability via a double Z-Scheme charge transmission procedure, as evident by the accumulation of α-Fe2O3 and CdS on the g-C3N4 surface. Also, a dark adsorption study was performed wherein the recorded adsorption kinetics of RhB and MB indicate pseudo-second-order in both cases. The synthesized 5 wt% FCG nanocomposite is anticipated to have countless abilities in photocatalytic performance and adsorption study as well.