Abstract:
A photocatalytic composite in powder form having
nanosized Cu2O/Cu granules wrapped in multilayered reduced
graphene oxide (rGO) sheets was synthesized. The fabrication
process was initiated by potentiostatic electrodeposition of n-type
Cu2O thin films on Ti substrates in an acetate bath. Peeled-off
Cu2O thin films were next subjected to ultrasonic mixing with
graphene oxide (GO) by maintaining a Cu2O/GO mass ratio of
125:10. Chemical reduction using ascorbic acid converted Cu2O
partially to Cu, while converting GO completely to rGO as
confirmed by Fourier transform infrared spectroscopy (FTIR), X ray photoelectron spectroscopy (XPS), and X-ray diffraction
(XRD). Transmission electron microscopy (TEM) images of the
composite confirmed the presence of Cu nanoparticles of the size
of tens of nanometers within the photocatalyst, Cu2O. The fabrication process therefore implicitly favors synthesis of nanosized Cu
playing the role of a co-catalyst. The Cu2O/Cu/rGO composite showed significantly higher ability to degrade methylene blue in
solution, while the effects due to photocorrosion were minimal during a month of testing when compared with Cu2O alone. The
layered rGO provides an effective medium for transporting photoelectrons to the reactant while inhibiting photocorrosion.
Furthermore, the composite demonstrated its ability to split water under visible light in the presence of methanol and creates a
promising platform to further develop a variety of other photocatalytic applications.
