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以Bi(NO_3)_3·5H_2O和NH_4VO_3为原料,控制水溶液介质p H及反应时间,采用水热合成法制备钒酸铋(BiVO_4)及其复合物(BiVO_4/Bi_6O_6(OH)_3(NO_3)_3).利用X-射线粉末衍射、扫描电子显微镜和紫外-可见漫反射吸收光谱等手段对制备的样品进行了物理表征,结果表明,在控制反应时间为1 h,介质p H值在1.14~9.01之间时,制备的样品为BiVO_4/Bi_6O_6(OH)_3(NO_3)_3复合物,当p H值增加至10.92时为纯BiVO_4;控制介质p H为7.17,反应时间在1~12 h之间时得到BiVO_4/Bi_6O_6(OH)_3(NO_3)_3复合光催化剂,反应时间为18 h时为纯BiVO_4.在可见光(λ≥400 nm)照射下,以有机染料罗丹明B(Rhodamine B,Rh B)为底物,研究不同条件制备的BiVO_4或者复合物为光催化剂的光催化特性,发现p H=7.17,水热反应12 h得到的催化剂(BiVO_4/Bi_6O_6(OH)_3(NO_3)_3)光催化降解活性高于对照制备的纯BiVO_4.同时在可见光照射下,BiVO_4/Bi_6O_6(OH)_3(NO_3)_3亦可以有效降解无色小分子2,4-二氯苯酚(2,4-Dichlorophenol,2,4-DCP),说明氧化过程涉及到光催化过程.分析BiVO_4/Bi_6O_6(OH)_3(NO_3)_3复合光催化剂对Rh B光催化降解过程中活性物种,表明在降解过程中主要涉及空穴和超氧氧化,O_2·~-起主要作用.
Bi (NO_3) _3 · 5H_2O and NH_4VO_3 were used as raw materials to control the pH of the aqueous medium and the reaction time. BiVO_4 and its complex (BiVO_4 / Bi_6O_6 (OH) _3 (NO_3) _3 ). The prepared samples were characterized by X-ray powder diffraction, scanning electron microscopy and UV-Vis absorption spectroscopy. The results showed that when the reaction time is 1 h, the medium p H value is between 1.14 and 9.01 The prepared sample was BiVO 4 / Bi 6 O 6 (OH) 3 (NO 3) 3 complex, pure BiVO 4 when the p H value increased to 10.92, the control medium pH was 7.17 and the reaction time was between 1 and 12 h BiVO_4 / Bi_6O_6 (OH) _3 (NO_3) _3 composite photocatalyst was obtained with pure BiVO_4 as the reaction time of 18 h.In the presence of visible light (λ≥400 nm), the organic dye Rhodamine B ) As substrate, the photocatalytic properties of BiVO_4 or composite prepared under different conditions were studied. It was found that the catalyst (BiVO_4 / Bi_6O_6 (OH) _3 (NO_3) _3) with p H = 7.17 and hydrothermal reaction for 12 h BiVO_4 / Bi_6O_6 (OH) _3 (NO_3) _3 was also effectively degraded in the presence of visible light The small molecule 2,4-Dichlorophenol (2,4-DCP) shows that the oxidation process involves the photocatalytic process.The effect of BiVO_4 / Bi_6O_6 (OH) _3 (NO_3) Photocatalytic degradation of the active species, indicating that in the degradation process mainly involves holes and superoxide oxidation, O 2 · ~ - play a major role.