采用水热法合成了形貌可控的磷酸铋纳米棒光催化剂,并以亚甲基蓝(MB)为探针研究了其光催化活性.利用粉末X射线衍射(XRD),透射电镜(TEM)和紫外-可见漫反射光谱(UV-VisDRS)对产物进行了表征.研究发现甘油含量、水热时间、水热温度及前驱体浓度会影响磷酸铋纳米棒的形貌及结构.甘油含量和前驱体浓度主要影响产物形貌.随着甘油含量的增加,产物的长径比先增大后减小.前驱体浓度越低,所得BiPO4纳米棒的尺寸越小,长径比越大.水热时间短时,产物结晶度差,且为六方相,时间延长后转化为单斜相.水热温度过低或过高均不利于完美晶体的形成,160°C时产物的结晶度最高.实验结果表明:BiPO4纳米棒在紫外光下具有良好的光催化性能,其光催化活性受长径比和尺寸大小影响的总体趋势是长径比越大,尺寸越小,其光催化活性越强.结晶度对BiPO4的光催化性能影响较大,结晶度越高,其光催化活性越好.单斜相BiPO4的光催化活性较六方相的强.
BiPO 4 nanorods with controlled morphologies were fabricated using a hydrothermal method. The photocatalytic activity of the BiPO 4 nanorods was investigated by their ability to degrade methylene blue(MB).The products were characterized by X-ray diffraction(XRD),transmission electron microscopy (TEM),and UV-Vis diffuse reflectance spectroscopy(DRS).It was found that glycerol content,reaction time and temperature,and concentration of precursor influenced the morphology and structure of the product. The glycerol content and concentration of precursor mainly influence the morphology of the product.As the glycerol content increases,the aspect ratio first increases,and then decreases.The aspect ratio of the product increases and the size decreases as the concentration of precursor is lowered.When the reaction time is short,the crystallinity of the product is poor,and it forms a hexagonal phase.Hexagonal BiPO 4 transforms into the monoclinic product when the reaction time is longer.The optimal temperature for crystal formation was found to be 160°C.The results show that BiPO 4 nanorods possess excellent photocatalytic activity under ultraviolet light.The photocatalytic activity of BiPO 4 increased with an increase of aspect ratio and decrease of particle size.The crystallinity of the product has a significant influence on its photocatalytic activity.BiPO 4 with higher crystallinity has higher photocatalytic activity,and monoclinic BiPO 4 has higher photocatalytic activity than hexagonal BiPO 4 .