Photocatalytic performance of Pr/In/Nd composite oxides synthesized by solid state reaction

摘要

Pr/In/Nd composite oxides with different Pr/In/Nd ratios were successfully prepared using a simple solid state reaction at 873 K. The composites were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area measurements, photolumi-nescence (PL) spectra and UV-vis diffuse reflection spectroscopy (UV-vis DRS). The photocatalytic activity of Pr/In/Nd composite oxides was investigated by the degradation of methyl orange (MO) in an aqueous solution under UV and visible light irradiation. It is found that compared with pure In_2O_3, the absorption intensity of the Pr/In/Nd composite oxide (Pr/In/Nd = 1:8:1) increases in the 200-800 nm light region and the absorption edge has a shift to longer wavelength. In addition, the Pr/In/Nd composite oxide (Pr/In/ Nd= 1:8:1) shows higher UV and visible light photocatalytic activities than pure In_2O_3. The remarkably enhanced photocatalytic activities could be mainly attributed to the fact that proper introduction of Pr_2O_3 and Nd2O5 increased the BET surface area of In_2O_3, improved the separation efficiency of photogenerated electrons and holes, and enhanced the absorption intensity in 200-800 nm light region. The effect of various radical scavengers on the degradation of MO showed that OH, O_2~-, h~+ and H_2O_2, especially O_2~-, jointly dominated the photodegradation process of MO under UV light irradiation.