Preprarationandphtoelectroni Cpropertiesofα-Fe₂O₃Nanostruct Ure Films

Much attention has been focused on the development of new energy resources and materials due to the increasingly serious energy shortage and environment pollution. The conversionof solar-to-chemical energy is a low cost and environment friendly method that is a wide range of potential applications.For several decades, semiconductor electrodes of the photoelectrochemical conversion have been a topic of great interest. Iron oxide (α-Fe2O3or hematite) with low band gap (whichabsorbs light up to600nm), low cost, and high chemical stability is one of the promising transition metal oxide semiconductor materials for this application. Nanomaterials can possess distinct photoelectronic properties.The paper describes the development and properties of nanomaterials and nanosemiconductor materials, and summarizes the research progress of iron oxide. The fabrication of a-Fe2O3nanostructure film is by thermal oxidation of iron deposit.We discussed iron oxidation behavior and photoelectric properties.In order to explore iron oxidation behavior,the effect of temperature and surface addition on oxide morphology,we obtained through directly thermal oxidation of iron deposit. The morphology, crystalline phase and composition of obtained thermal oxidation products were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD). The results show that oxide layer are two layers on iron basement after thermal oxidation, FeaO4layer and a-Fe2O3layer. Fe3O4layer is next to basement.With continous oxidation, the a-Fe2O3nanostructure film composed of nanobelts and nanoplates is obtained.Pt film enhanced photoelectric properties of the a-Fe2O3nanostructure film.The morphology of iron oxide is plate-like at500℃in air,and nanorods with oxalic acid on substrate.Based on improving the stability of photoelectrode basement, a layer of Iron deposit was deposited on titanium foil through electroplating method, and then thermal oxidation of this deposit was carried out. The morphology, crystalline phase and composition of obtained thermal oxidation products were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Electron Back-Scattered SEM (EBS-SEM) and energy-dispersive X-ray (EDX) spectroscopy, surface photovoltage and photoelectrochemical properties of this thermal oxidation products were studied by surface photovoltage spectrum (SPS), phase spectrum (PS) and I-V curve test. The results show that a-Fe2O3nanostructure film was obtained after thermal oxidation of iron deposit. The a-Fe2O3nanostructure film was composed of nanobelts and nanoplates. A surface photovoltage response related to band-band transfer in300-600nm was found in α-Fe203nanostructure film. According to phase spectrum, a-Fe2O3nanostructure film exhibits n-type semiconductor electronic conductivity. The I-V curve of a-Fe2O3nanostructure film showed that0.58mA/cm2of short circuit current density (JSC) was achieved at0.23V vs. Ag/AgCl under100mW/cm2simulated AM1.5sunlight.