Anodization is a widely used method to obtain multicolored oxidized titanium sheets. However, most researchers paid great attention to the color related properties of TiO₂ nanotube instead of photoelectrical properties of titanium oxide film. In this work, to study their photoelectrical properties, a series of multicolored oxidized titanium sheets were prepared by anodization method, and UV-Vis absorption and photocurrents were tested. The anodized titanium sheets not only can be used as decoration material such as Jewelry, but also are supposed to be used as photoelectrical catalyst. The relationship between anodization voltages/anodization durations and photocurrents of titanium sheets was studied. Results show that titanium sheets have excellent photoelectrical performance. With the increase of anodization voltage, number of UV-Vis absorption peaks increased under visible light which means increasing absorption. When anodization duration increased, absorption band edge also increased in visible light region, which means band gap needed to produce charge transfer transition decreased. Under simulated sunlight and applied voltage of +0.4V, photocurrent increased with the increase of either anodization voltage or anodization duration, and can be expressed by linear equations respectively. In addition, anodization currents were recorded during anodization. Morphology, crystal structure and photoelectrical properties of anodized titanium sheets were characterized.

1. Anodization current recording

Universal electric meter (Fluck289, USA)                                  

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2. Characterization of crystal structure (XRD and Raman)       

X-ray diffraction (XRD) patterns were obtained through a UItimaIV diffractoneter (Japan). Raman spectra were collected on a Micro-Raman spectrometer RM 2000 (Renishaw in Via-reflex, 532 nm excitation laser).     

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3. UV-Vis absorption     

Ultraviolet-Visible (UV-Vis) spectra were taken with an UV-3900H spectro-photometer (Hitachi, Japan).    

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4.Photoeletrical performance   

Photoelectrical properties were tested using electrochemical workstation with a solution of 0.05 mol L^-1 Na₂SO₄ as electrolyte. The anodized titanium sheet was used as working electrode, counter electrode was graphite rod, and reference electrode was Ag/AgCl. A 500 W Xenon lamp was placed in front of the working electrode as  simulated sunlight source with wavelength range of 200-900 nm.

The names of tables and tables are described, includes 5 summary tables.