Preparation and characterization of ZnO/α-Fe₂O₃ photoanode: Potential for solar cells application

Full text: There is a constant requirement to diversify the energy matrix due to the socio environmental and economic impacts caused by the use of fossil fuels. In this context, renewable energies, such as solar cells, stand out as a possible solution to this problem [1]. In this work, it was produced photoanodes of zinc oxide particles decorated by hematite (α-Fe₂O₃). We used a hydrothermal assisted microwave method to produce the zinc oxide and the hematite particles. After that the photoanode of FTO/ZnO/Fe₂O₃ was produced. The films were deposited on FTO substrates were made following published methodology [2]. A typical electrochemical cell system was assembled with 3 electrodes, work (FTO/ZnO;FTO/ZnO/Fe₂O₃ films), reference (Ag/AgCl) and counter electrode (Pt) immersed in an electrolytic solution composed of acetonitrile, KI, I₂ and LiClO₄. These materials were characterized by X Ray Diffraction, nitrogen adsorption-desorption isotherms, Linear Sweep Voltammetry (LSV), Chronoamperometry, Scanning Electron Microscopy, Micro Raman and FTIR spectroscopy, techniques to determinate their potentialities for solar cell applications. The LSV showed a high current density of the FTO/ZnO/Fe₂O₃ (0,58 mA.cm^-2) film being superior to the FTO/ZnO (0,16 mA.cm^-2) film in light condition. The analysis showed that these materials are promising photoanode for solar cells applications, characterizing them a ZnO particles were decorated by Fe₂O₃ nanoparticles and improving the photoelectrochemical properties. It has been ascertained that the composite material is promising for a solar cell applications and the method used as a low-cost, fast and ecologically alternative for the production of these components. Reference: [1] DINCER, I. Renewable and Sustainable Energy Reviews, v. 4, n. 2, p. 157-175, 2000. (author)