Preparation of three dimensional graphene foam–WO₃ nanocomposite with enhanced visible light photocatalytic activity

Three dimensional graphene foam (3D GF) was synthesized by chemical vapor deposition (CVD) on a nickel foam skeleton. After dissolving the nickel foam, the obtaining 3D GF was used as a highly porous conductive substrate for nucleation and growth of WO₃ particles. Scanning electron microscopy (SEM) and Raman spectroscopy was employed to ensure the quality of the prepared GFs and to judge about the 3D GF–WO₃ chemical structure. The WO₃ characteristic Raman peaks centered at 726, and 809 cm⁻¹ are slightly broadened and displaced to lower wavelength in the 3D GF–WO₃ nanocomposite, as compared to the corresponding peaks of the bare tungsten oxide. This phenomenon confirms the formation of W–C and W–O–C bonds in composite material which is important for faster transferring the photoexcited electrons to graphene 3D network as an exceptional electron acceptor. The 3D GF−WO₃ composite material was applied in photocatalytic degradation of Rhodamine B dye. It was observed that the annealed samples show an excellent photocatalytic performance relative to the as-prepared 3D GF−WO₃ samples and bare WO₃, which is ascribed to the lower electron/hole recombination through the formation of W–C and W–O–C bonds. - Highlights: • 3D GF synthesized by CVD on a nickel foam as a highly porous conductive substrate. • WO₃ nanoparticles coated on 3D GF by dip-coating. • 3D GF−WO₃ shows an excellent photocatalytic degradation of Rhodamine B dye. • Better photocatalytic properties assigned to the formation of W–C and W–O–C bonds