Abstract
•MgO@g-C3N4 nanocomposite was ultrasonically fabricated using the precursors MgO and g-C3N4.•The anchoring of MgO and g-C3N4 was verified by XPS, XRD and EDX techniques.•The nanocomposite has proficiently degraded the indigo carmine dye during a visible light driven process.•A Z-scheme model was suggested for the enhanced as confirmed through the *O2−, h+ and *OH involvement.
Herewith, a direct MgO@g-C3N4 photocatalyst lacking an electron mediator was synthesized via a facile calcination route exploiting MgO and g-C3N4 as precursors. The XRD, SEM, and XPS analysis confirmed the composite formation while the UV–Vis and N2 adsorption connoted a bangap 2.84 eV for the composite compared to 3.75 eV for MgO and larger surface area of 84 m2 g−1 than the 37 m2 g−1 the pure MgO. The Photocatalytic action of the as-prepared samples was assisted by the degradation of the indigo carmine (IC) dye in an aqueous solution under visible light illumination. The reaction was found to comply with the pseudo-first-order kinetics and the rate constant using MgO@g-C3N4 was 14 times that using g-C3N4. The superior photocatalytic performance could be credited to the formation of a MgO@g-C3N4 Z-scheme photocatalyst, which results in the efficient charge carriers separation. In view of the simple and efficient preparation protocol, this study will offer insights into the excellent performance of the Z-scheme for dye photocatalytic degradation.