Chemical Engineering Transactions (Feb 2020)

Synthesis of Zinc Oxide/Reduced Graphene Oxide Composites for Fabrication of Anodes in Dye-Sensitized Solar Cells

  • Tran Trung Nghia Le,
  • Van Cuong Le,
  • Tien Phat Le,
  • Thi Tra My Nguyen,
  • Huu Dat Ho,
  • Khac Hung Le,
  • Minh Hien Tran,
  • Thai Hoang Nguyen,
  • Trong Liem Chau Pham,
  • Hoang Minh Nam,
  • Mai Thanh Phong,
  • Nguyen Huu Hieu

DOI
https://doi.org/10.3303/CET2078011
Journal volume & issue
Vol. 78

Abstract

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In this study, graphene oxide (GO) was synthesized using the improved Hummers’ method, and reduce graphene oxide (rGO) was synthesized from GO with hydrazine hydrate as reducing agent. Zinc oxide (ZnO) was synthesized from zinc acetate using the precipitation method. Zinc oxide/reduced graphene oxide (ZnO/rGO) composites were synthesized using the ex-situ method. The ZnO/rGO composites with different rGO weight percents (0.05, 0.1, 0.5, 1, and 5 wt%) were used for fabrication of ZnO/rGO anodes. A control anode was fabricated from ZnO (ZnO anode). The band gaps of fabricated anodes were measured using the ultraviolet-visible spectroscopy (UV-vis). The dye-sensitized solar cells (DSSCs) were assembled and investigated by current density-voltage (J-V) curves and electrochemical impedance spectroscopy (EIS). The ZnO/rGO composite with appropriate rGO content was determined to be 1 wt%, with the efficiency of 1.55 %. The Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD) results confirmed wurzite structure of ZnO and the reduction of functional groups of GO to create rGO and ZnO/rGO. The transmission electron microscopy (TEM) showed that the ZnO nanoparticles with size of 10 - 20 nm were evenly distributed on rGO sheets. These results indicated that ZnO/rGO could be the potential material to improve the efficiency of DSSCs.