摘要
采用溶胶-凝胶法对纳米ZnO-TiO2复合半导体进行了La3+改性,用热重-差示扫描量热、扫描电镜、X射线衍射和拉曼光谱分析了La3+/ZnO-TiO2的晶化温度和微晶结构,并以活性艳红K-2BP为模型降解物,在固定催化剂投加量和通气量条件下考察了La3+掺杂量和煅烧温度对La3+/ZnO-TiO2光催化活性的影响.结果表明,La3+掺杂使ZnO-TiO2晶型转变温度提高,衍射峰蓝移且峰强度减弱,晶粒进一步减小.La3+掺杂量为0.5%,煅烧温度为500℃,40min时对活性艳红K-2BP的降解率为100%,表观反应速率常数k值达到了0.182min-1,为不掺La3+的ZnO-TiO2复合半导体的1.4倍.
Modification of nanocrystalline coupled semiconductor ZnO-TiO2 by means of La^3＋ doping using the sol-gd method was investigated. Thermogravimetry-differential scanning calorimetry, scanning electron microscopy, X-ray diffraction, and Raman spectroscopy were employed to analyse the structure and morphology of La3 ＋/ZnO-TiO2. The degradation of reactive red K-2BP was used to evaluate the photocatalytic activity of the catalyst under UV-lamp （253.7 nm, 20 W） irradiation. Effects of La^3＋ doping concentration and calcination temperature on photocatalytic activity were investigated at a fixed photocatalyst amount and air flow rate. The results showed that La^3＋ doping caused an increase in crystal transformation temperature, a strong blue shift of diffraction peaks, and a decrease in grain size. The reactive red K-2BP could be fully degraded within 40 min when La^3＋ doping content was 0.5 % and calcination temperature was 500 ℃. Under these conditions, the apparent absorption coefficient reached 0. 182 min^-1, which was 1.4 times as large as coupled semiconductor ZnO- TiO2,
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2007年第10期885-889,共5页
基金
西安工程大学高级氧化功能实验室基金(ZD20050312)
陕西省教育厅专项科研计划(07JK248)
关键词
镧
氧化锌
氧化钛
复合半导体
稀土掺杂
光催化活性
活性艳红
lanthanum
zinc oxide
titania
coupled semiconductor
rare-earth doping
photocatalytic activity
reactive red
