以硝酸铋、 钨酸钠等为原料, 利用水热法在150 ℃下反应24 h得到Bi2WO6纳米晶。 X射线粉末衍射结果表明, 所制备的Bi2WO6属于正交晶系, 晶胞参数为a=5.457, b=16.435及c=5.438 。 XPS结果表明所制造的Bi2WO6纯度较高。 研究了分别以水、 N,N-二甲基甲酰胺、 乙二醇为溶剂时所制备Bi2WO6样品在可见光激发下对罗丹明B的降解活性, 结果表明, 以乙二醇为溶剂时, Bi2WO6光催化活性最佳, 主要是由于在乙二醇中制备的Bi2WO6分散性好, 粒径小, 对紫外-可见光具有较大波长范围的吸收所致。 另外, 研究了以水为溶剂时溶液pH及添加表面活性剂等对所制备Bi2WO6光催化活性的影响, 结果表明, 反应温度为140～150 ℃, pH在1.0附近及添加SDS后所制备Bi2WO6光催化活性较佳。 荧光光谱分析发现, 添加表面活性剂的样品发射荧光的强度较弱, 表明载流子复合程度低, 因而光催化效率高。

In the present study, bismuth tungstate(Bi2WO6) nanocrystals were prepared by the hydrothermal method using bismuth nitrate (Bi(NO3)3·5H2O) and sodium tungstate (Na2WO4·2H2O) as raw materials at 150 ℃ for 24 h. The powder X-ray diffraction (XRD) pattern shows that the Bi2WO6 nanocrystals belong to the orthorhombic phase with calculated lattice constants a=5.457 , b=16.435  and c=5.438 . The X-ray photoelectron spectra (XPS) indicate that the obtained Bi2WO6 was pure. The photocatalytic activity of the nanocrystal prepared by using water, N, N-dimethyl formamide (DMF) and ethylene glycol (EG) as the solvent respectively were studied for the degradation of rhodamine B under visible light irradiation. The results show that Bi2WO6 sample obtained in EG has the best photocatalytic activity mainly owing to good dispersion, small particle size and broader spectrum response for visible light. In addition, the influence of pH and surfactant on the Bi2WO6 photocatalytic activity was also studied. The results show that Bi2WO6 sample has better photocatalytic activity when prepared at 150 ℃ and pH 1.0 with sodium dodecylsulfate (SDS) as the surfactant. The photoluminescence (PL) spectra of the prepared Bi2WO6 reveal that the recombination of photo-generated electrons and holes was inhibited over Bi2WO6 prepared with SDS and thus its photocatalytic ability was enhanced.