Graphitic Carbon Nitride Nanosheet/FeWO₄ Nanoparticle Composite for Tandem Photooxidation/Knoevenagel Condensation

Abstract

A facile and convenient process for the fabrication of a Z-scheme heterojunction g-C3N4 nanosheet/FeWO4 nanoparticle composite is reported. The structure of the synthesized g-C3N4/FeWO4 nanocomposite was analyzed by a variety of techniques including X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, diffuse reflectance spectroscopy (DRS), energy-dispersive X-ray spectroscopy (EDX), inductively coupled plasma optical emission spectroscopy (ICP-OES), photoluminescence spectroscopy (PL), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The obtained results from DRS and PL analyses confirmed that the as-prepared nanocomposite g-C3N4/FeWO4 illustrated improved photocatalytic performance compared with pristine graphitic carbon nitride. The Z-scheme heterostructured nanocomposite (g-C3N4/FeWO4) with a suitable band structure shows efficient photocatalytic activity due to the spatial separation of charge carriers. The obtained g-C3N4/FeWO4 heterostructured photocatalyst demonstrated high efficiency in the tandem photo-oxidation/Knoevenagel condensation reaction under visible illumination and O2 atmosphere as a green oxidant. The catalytic activity of the g-C3N4/FeWO4 did not show considerable decline even after five cycles of use.