(1. 惠州学院 化学工程系，惠州 516007；
2. 中南大学 化学化工学院，长沙 410083)
摘 要: 以Bi(NO3)3·5H2O、NaVO3和La(NO3)3·5H2O为原料，以葡萄糖为结构导向剂，通过水热法制备La掺杂BiVO4微米球。采用XRD、XPS、SEM、FTIR、UV-Vis、BET、光催化技术等对产品进行了表征和分析。结果表明，采用葡萄糖(2.0 g)辅助水热法能合成结晶度高且形貌规整的单斜白钨矿La/BiVO4微米球，微米球直径范围为2~9 μm，均由尺寸为30~65 nm纳米颗粒自组装而成。相比BiVO4块状颗粒，球状La/BiVO4的紫外-可见光吸收边发生了稍许红移，具有较小的能带隙(＜2.4 eV)，其中，2.0%La/BiVO4(质量分数)微米球表现出最高的光催化活性，其速度常数k为5.63×10-2 min-1，可见光照射10 mg/L亚甲基蓝溶液60 min时的光解率达100%。
关键字: La/BiVO4；微米球；水热法；掺杂；光催化
（1. Department of Chemical Engineering, Huizhou University, Huizhou 516007, China;
2. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract:Using Bi(NO3)3·5H2O, NaVO3 and La(NO3)3·5H2O as raw materials, La-doped BiVO4 microspheres were characterized and analyzed by hydrothermal process with glucose as the template. The as-prepared samples were investigated by XRD, XPS, SEM, FTIR, UV-Vis, BET and photocatalysis techniques. The results reveal that uniform, well crystallized and microspherical La/BiVO4 monoclinic crystal with the diameter range of 2-9 μm, which is self-assembled by lots of nanoparticles with the size of 30-65 nm, can be obtained via a hydrothermal route assisted by 2.0 g glucose. Compared with BiVO4 irregular particles, La/BiVO4 microspheres show a little red shift in the absorption band, resulting in a narrowed band gap (＜2.4 eV). For 2.0% La/BiVO4 (mass fraction) microspheres, its photodegradation rate constant k is 5.63×10-2 min-1 and the best photocatalytic activity is found with a 100% degradation of methylene blue (MB) with a concentration of 10 mg/L under visible-light irradiation for 60 min.
Key words: La/BiVO4; microspheres; hydrothermal method; doping; photocatalysis
