掺杂型纳米微球Cr-TiO_2的原位水热合成及其光催化降解抗生素(氯霉素)性能

Preparation of Cr-Doped TiO_2 Nanoparticle by in Situ Hydrothermal Method and Photocatalytic Degradation of Antibiotics

采用水热法合成了掺杂型Cr-TiO2复合纳米微球,通过XRD、SEM、DRS、BET等对样品进行了表征和分析,探讨了Cr掺杂量在0.03%-0.1%(Cr:TiO2;摩尔比)范围内时对TiO2光催化性能的影响。掺杂型Cr0.03-0.1-TiO2光催化剂为不规则纳米球状颗粒的平均粒径为40 nm,锐钛矿相晶型,其中Cr0.05-TiO2禁带宽度为3.08 eV,比表面积为65.64 m2/g,平均孔径17.9 nm,比纯TiO2的孔径大两倍。以氯霉素(CAP)为抗生素代表,考察了掺杂型Cr0.03-0.1-TiO2的光催化降解性能,确定了最佳光催化性能样品的Cr掺杂量。结果表明,在高压汞灯(125 W)120 min的辐照下,Cr0.05-TiO2对CAP的降解率可达96.8%。CAP的光催化降解服从一级动力学规律,测得降解速率常数k为3.4×10-2min-1,半衰期t1/2为12.4 min。

The Cr-doped TiO/（ Cr-TiO2 ） composite nanoparticle photocatalyst is synthesized by in situ hydrothermal method, the samples are characterized by XRD, SEM, DRS and BET techniques, and the effect of different amounts （0.03% - 0.1% ; mole ratio） of Cr-doped on photocatalytic performance of TiO2 is discussed. The Cro.03.0.1-TiO2 is irregular spherical nanoparticles with anatase phase, average par- ticle size is 40 nm, the bandwidth of Cr0.05-TiO2 is 3.08 eV, and specilic surface area is 65.64 m2/g. The average pore size of Cro.05-TiO2 that is 17.9nm is twice as big as the pure TiO2. The chloramphenico] （CAP） as the representative of antibiotics, the photocatalytic activities of the Cr0.03.0.1-TiO2 photocatalyst are evaluated by monitoring the photocatalytic degradation of CAP under UV irradiation, the 0.05% is optimal amount of doping. The results show that the degradation rate of CAP can reach 96.8% under high pressure mercury lamp（ 125 W） irradiation in 120 rains. The photocatalytic degradation of CAP can followed the first-order reaction model, and the rate constant k of 3.4 × 10-2 minl and the half-life t1/2 of 12.4 min are evaluated.