Production of a ZnO–rGO composite, using a novel one-pot method consisting in continuously flowing argon into a GO aqueous suspension heated at 80 °C, in the presence of galvanized iron steel scrap is presented. FTIR shows the complete disappearance of GO functional groups and only the C=C band remained, indicating extensive GO reduction. Raman spectra indicated sp² character increase after reaction and the presence of the E_2h mode of ZnO. SEM showed submicron crystals identified by XRD as ZnO in the hexagonal phase, while TEM images indicate ZnO nanoparticles decorate mainly the rGO borders. Optical band gap of 3.5 eV corresponding to ZnO, and optical transitions at 4.1 and 5.5 eV related with n → π and π → π* were observed. Electrochemical characterization by cyclic voltammetry shows an specific capacitance of 4.7 F g⁻¹ at a scan rate of 5 mVs⁻¹, which drops to ca. 0.8 F g⁻¹ at 200 mVs⁻¹. By electrochemical impedance spectroscopy, the relaxation time was ca. 5 ms. The proposed mechanism for the materials‘ synthesis includes Zn dissolution from scrap, galvanic displacement of oxygen moieties at the GO sheet, Zn deposition onto the carbon surface, and further oxidation and growth of ZnO nanocrystals.

Graphene oxide, as a nanoscopic platform for functional materials, has been extensively studied for several applications. The present Mini Review stresses the collaborative research in graphene-oxide materials pivoted from the Group of Materials and Technologies for Energy, Health, and Environment at an Instituto Politecnico Nacional unit in Tamaulipas, in Northeastern Mexico, with Mexican, Turkish, and British collaborators. This review covers the recent works on photovoltaic and photocatalytic materials, coatings for thermonuclear reactors, and composites and metamaterials for military and aeronautic applications.

In this work, copper (I) oxide films were prepared by pulsed electrodeposition onto copper substrates. Graphene oxide was deposited on the Cu₂O/Cu films by cathodic electrophoresis. The films were studied by X-ray diffraction, Raman spectroscopy, optical reflectance and atomic force microscopy. The bandgap of the Cu₂O/Cu films is close to 1.8 eV due to the presence of defects and decreases to close to 1.1 eV with GO deposition due to the oxidation of Cu₂O to CuO on the surface. When GO was deposited, a reduction in the mean height was observed, indicating coverage of the entire surface. A topographic transformation of the surface was also observed, consisting of an increase in grain size and homogenization of the grain shape after GO deposition, possibly due to phase transformation. This work is the first step to prepare fully wet deposited thin film ZnO/GO/Cu₂O/Cu solar cells.