Potassium-Functionalized Graphitic Carbon Nitride Supported on Reduced Graphene Oxide as a Sustainable Catalyst for Knoevenagel Condensation

A nanocomposite of potassium-functionalized graphitic carbon nitride (KGCN) and reduced graphene oxide (RGO) was fabricated by a facile hydrothermal method and used as a heterogeneous catalyst for Knoevenagel condensation and sustainable synthesis of aryl substituted chromenes. The prepared KGCN-RGO nanocomposite catalyst has been characterized by using various techniques, such as powder Xray diffraction technique (PXRD), Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscope, thermogravimetric analysis, and BET surface area analysis. After detailed characterization, the nanocomposite was used as a heterogeneous catalyst to synthesize various aryl substituted chromenes in ethanol. The developed KGCN-RGO nanocatalyst also rendered good recyclability for the explored catalytic reactions. In addition, a high value of atom economy and a low value of E-factor are also key highlights of this green and sustainable catalytic protocol.