Efficient Visible Light Active Photocatalyst: Magnesium Oxide-Doped Graphitic Carbon Nitride for the Knoevenagel Condensation Reaction

Abstract

In the present work, we have developed visible light active photocatalysts by incorporating magnesium oxide (MgO) as a dopant (with varying loadings, viz., 3, 5, and 10%) onto graphitic carbon nitride (g-C3N4) nanosheets prepared via urea and dicyandiamide as precursors to form MgO@g-C3N4 catalysts. These photocatalysts showed impressive photocatalytic performance in the Knoevenagel condensation reaction using a low-power visible LED light (12 W), surpassing that of pure g-C3N4. In order to characterize photocatalysts, various techniques have been used, such as FTIR, XRD, XPS, TEM, EIS, UV–vis DRS, and thermogravimetric analysis. Based on this study, the MgO@g-C3N4 catalyst with 5% MgO loading has shown an outstanding performance with 98.53% conversion and 98.98% selectivity. Furthermore, the catalyst showed minimal drop-in activity after five cycles of recyclability. This study highlights MgO@g-C3N4 as a promising and sustainable photoactive material for efficient photocatalytic applications.