Bi_2Mo_xW_(1-x)O_6固溶体的水热合成、表征及光催化性能

Hydrothermal Synthesis, Characterization and Photocatalytic Activities of Bi_2Mo_xW_(1-x)O_6 Solid Solution

采用水热法成功合成了一系列Bi2MoxWl，O60=0～1）固溶体，通过XRD、DRS、FT-IR等方法对合成产物进行了表征。随着产物中Mo含量的增加，XRD图谱位于20=-33°、47°、56°处的峰逐渐发生分裂，I（131）／1（200）比值先逐渐增大后缓慢降低；红外光谱的金属一氧键的振动频率由821cm。逐渐蓝移至842cm～。表明生成了互溶的固溶体；借助DRS测得样品的带隙分别为2．75、2．55、2．50、2．45、2．59、2．63eV伍=O、0．25、0．50、0．75、0．9、1）。可见光下，以罗丹明B为目标降解物进行了合成产物的光催化性能测试。结果显示：Bi2M0075W02506固溶体的光催化活性最高。固溶体特殊的结构和较窄的带隙是影响光催化效果的主要因素。

BizMOxWl_xO6 （x=0-1） solid solutions were successfully synthesized via a facile hydrothermal method. The obtained products were characterized by X-ray diffraction, UV-Vis diffuse reflectance spectra and FT-IR spectrum. With an increase of Mo content, XRD patterns of the as-synthesized products show that the peaks at 20=-33~, 47~, 56~ gradually split, and the value of 1（131）/I（200） gradually increases and then slowly decreases. FT-IR absorb band around 821 cm＂l, which refered to the vibration frequency of the metal-oxygen band, is monotonically shifted to 842 cm-1. According to DRS calculations, the band gap of the samples are 2.75, 2.55, 2.50, 2.45, 2.59 and 2.63 eV when x is 0, 0.25, 0.5, 0.75, 0.9 and l, respectively. This result demonstrates the formation of soluble solid solution. The photo- catalytic activities of the products were evaluated by monitoring the degradation of RhB under visible light. It is found that, among solid solutions, the Bi2Mo0.75W0.2506 exhibites the highest photocatalytic activity which mainly attributes to the special structure of solid solution and the lower energy band gap.