高分散型钇修饰氧化铋纳米材料的制备及其可见光降解染料研究

Synthesis of highly dispersed Y-doped Bi_2O_3 nanomaterials and its photodegradation of dye under visible light irradiation

利用炭黑吸附-沉淀法,以Y_2O_3和Bi_2O_3为原料制备钇修饰的Y-Bi_2O_3纳米材料,通过改变制备条件(焙烧温度)调节材料的性质。研究结果表明:炭黑的添加抑制了晶粒在焙烧过程中的聚集长大,促进了Bi_2O_3晶相由α相向β相结构的转变,形成具有较大比表面积、较小粒径和高分散性的材料,改善了材料的光吸收性质,因而增强了其光催化降解甲基橙的活性。Y^(3+)具有可变价态,可以捕获光生e^--h^+形成Y^(2+)/Y^(4+),且可调节表面酸碱性,从而提高光催化活性。此外,对光催化降解甲基橙的反应机理也做了研究。

Nano-sized Y-doped Bi2O3 materials were feasibly prepared by carbon adsorption precipitation method,using yttrium oxide and bismuth oxide as raw materials.The properties of nanomaterials were adjusted via changing synthesis condi- tions, such as calcination temperature.It was found that the addition of carbon black proved the phase transition of Bi203 form- ing a-Bi2O3/β-Bi2O3 structure, inhibited grains growth in the process of calcination and favored the formation of samples with larger specific surface area, small particle sizes, and high dispersion, which enhanced optical absorption properties and photodegradation activity of methyl orange.Y3＋ could trap photogenerated electrons-holes pairs forming Y2＋/Y4＊,changed surface acid-base property, and thus facilitated the photodegradation effficiency.Meanwhile, the mechanism of photocatalysis of methyl orange was also studied.