钼酸铋光催化剂的制备及其光催化活性  

Preparation and visible-light photocatalytic degradation activity of bismuth molybdate composite

作　　者：李新玉[1] 方艳芬[1] 熊世威[1] 贾漫珂[1] 黄应平[1] 

机构地区：[1]三峡库区生态环境教育部工程研究中心,三峡大学443002

出　　处：《环境化学》2013年第9期1611-1618,共8页Environmental Chemistry

基　　金：国家自然科学基金(20877048;21177072;21207079);湖北省创新群体项目(2009CDA020);湖北省高等学校优秀中青年科技创新团队计划(T200703)资助;三峡大学人才科研启动基金(KJ2011B074);三峡大学研究生创新基金(2012CX079)资助

摘　　要：以表面活性剂聚乙二醇(PEG6000)为模板剂,调节其用量(0、10、20、30、40 g·L-1)通过水热法制备得到Bi3.64Mo0.36O6.55/Bi2MoO6纳米光催化剂,分别命名为(BMO-0、BMO-1、BMO-2、BMO-3,BMO-4).采用X-射线衍射仪(XRD),扫描电子显微镜(SEM),紫外可见漫反射(DRS UV-Vis)和比表面仪(BET)对其进行表征,结果表明,制备得到的钼酸铋为立方相Bi3.64Mo0.36O6.55和单斜相Bi2MoO6的混合物,形貌为纳米片和纳米颗粒的混合体.在可见光(≥420 nm)照射下,研究了Bi3.64Mo0.36O6.55/Bi2MoO6光催化降解罗丹明B(Rhodamine B,RhB)和苯酚(phenol)的催化特性,探讨了在光催化剂制备过程中PEG6000用量对其可见光活性的影响,发现当PEG6000用量为20g·L-1时其光催化活性最好.可见光下照射2.5 h即可使RhB(1.37×10-5mol·L-1)100%脱色,光照12 h后对苯酚(1.48×10-3mol·L-1)的降解率达到35.15%.采用DPD分光光度法测定了体系中产生的双氧水(H2O2),并结合外加叔丁醇(t-butanol)、碘化钾(KI)等捕获剂试验,推测其催化机理主要为空穴氧化和超氧自由基(O·-2)协同氧化历程.Bismuth Molybdate composite photocatalysts （Bi3.64Mo0.36O6.55/Bi2MoO6） were prepared in the presence of surfactant PEG6000 using the amild hydrothermal treatment method. The prepared catalysts were named as BMO-0, BMO-1, BMO-2, BMO-3, BMO-4, corresponding the surfactant dosage of 0,10,20,30 and40 g·L^-1 The materials were characterized by X-ray diffraction, scanning electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy and BET surface area analyzer. It showed that the composite was consisted of cubic Bi3.64Mo0.36O6.55 nanoparticles and orthorhombic Bi2MoO6 nanoplates. Under visible light the photocatalytic degradation reaction of the Rhodamine B （RhB） and phenol was used to evaluate the photocatalytic activity of Bi3.64Mo0.36O6.55/Bi2MoO6. The effect of PEG6000 dosage was also investigated. It was indicated BMO-2 had the highest photocatalytic activity in the presence of 20 g·L^-1PEG6000. Under visible light irradiation, RhB was completey degraded within 2.5 h, and 35.15% phenol was be degraded within 12 h using BMO-2. To determine the degradation mechanism, the intermedrate product H2O2 was detected by horseradish peroxidase spectro-photometry during the oxidative process. Radical trapping experiments with tertiary butanol and potassium iodide （KI） were also carried out. A possible oxidation mechanism involving the valence band hole and O2·- was propsed for the Bismuth Molybdate composite photocatalytic system.

关 键 词：钼酸铋 水热合成 光催化 

分 类 号：O643.36[理学—物理化学]