Preparation and characterization of CeO_2 decorated TiO_2 nanotube arrays photoelectrode and its enhanced photoelectrocatalytic efficiency for degradation of methyl orange

摘要

The highly oriented CeO_2/TiO_2 nanotube arrays (CeO_2/TiO_2 NTAs) were fabricated by the electrode-position of CeO_2 in 1.0 mol/L Na_2SO_4 aqueous solution on TiO_2 NTAs. CeO_2/TiO_2 NTAs were characterized by SEM, TEM, XRD, XPS. Its ultraviolet-visible absorption and photoelectrochemical properties were investigated. The degradation of methyl orange was used to evaluate the photoelectrocatalytic activity of CeO_2/TiO_2 NTAs. The results showed that the CeO_2 nanoparticles with a homogenous spherical size of about 15 nm were uniformly deposited onto the surface of TiO_2 NTAs. The CeO_2 composed with Ce~(4+) and Ce~(3+) ions could be observed. CeO_2/TiO_2 NTAs exhibited a stronger UV and visible light absorptions with 40 nm red-shift of the absorption edge compared with TiO_2 NTAs. The separation efficiency of the photogenerated charge carriers of CeO_2/TiO_2 NTAs can significantly enhanced by the CeO_2 deposited. The removal efficiencies (98.1 %) of methyl orange at the CeO_2/TiO_2 NTAs photoelectrodes was larger than that of the bare TiO_2 nanotube arrays photoelectrode (78.1 %).