In situ synthesis of iron oxide/pyrite composite by vapour deposition process and its photoelectricity properties

Key words:  hydrothermal method  nanoiron oxide  pyrite  vapour deposition

Abstract:

FeOOH as a precursor of iron oxide was prepared by hydrothermal method on Ti substrate. The titanium sheet with FeOOH and sodium thiosulfate were placed in a quartz crucible. Then, using Ar gas as carrier gas at high temperature, the sodium thiosulfate decomposed into elemental sulfur in the gas phase and participated in the chemical reaction, through which the composite of pyrite and Fe₂O₃ nano arrays was in-situ synthesized on iron oxide nanorod arrays by controlling the calcination temperature. The X-ray diffraction, field emission scanning electron microscopy and Raman spectra were used to analyze the crystal phase, morphology of the composites. The linear sweep voltammetry, photocurrent-time impedance and Mott-Schottky curves of Fe₂O₃/FeS₂ composites were measured by electrochemical workstation. The results show that pyrite can be observed on the surface of the Fe₂O₃ nano arrays. The composite has optimum photo electrochemical properties at the calcination of 500 ℃, and its photocurrent density greatly can be increased from 0.32 mA/cm² to 3.68 mA/cm².