| 金属掺杂二氧化钛光催化还原硝酸氮 |
| 摘要点击 2809 全文点击 3869 投稿时间：2007-09-30 修订日期：2007-11-09 |
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| 中文关键词 光催化 硝酸氮 光沉积 金属掺杂 |
| 英文关键词 photocatalysis nitrate photodeposition metal-doped |
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| 中文摘要 |
| 采用光沉积法制备了负载金属Fe或Cu的P25二氧化钛光催化剂,用TEM、ICP、XRD及UV-Vis等对其进行了表征,并测定其在20 W紫外灯照射下光催化还原硝酸氮、去除总氮的效果;考察了pH值、搅拌气体、金属的负载量、空穴清除剂甲酸的用量以及金属Ag-Cu复合沉积等条件的影响.反应2 h的结果表明,二氧化钛上载铜量增加,硝酸氮转化率随之增加,但最大总氮去除率和氮气选择性均出现在0.5% Cu负载量下;氮气搅拌和酸性条件下反应,形成氮气的选择性略低(62%),但最高的硝酸氮转化率和总氮去除率分别达到36.9%和23.2%;CO２作为搅拌气体,Cu的负载量为0.5%、甲酸用量为0.06mol/L 时,形成氮气选择性最好(88.4%),硝酸氮转化率和总氮去除率分别为29.5%和25.1%.同样条件下,采用二氧化钛上共沉积金属总质量分数为1%、Ag∶Cu=1∶1的催化剂,硝酸氮的转化率可达48.1%,总氮去除率为34.2%,氮气选择性为72.2% |
| 英文摘要 |
| Metal Fe or Cu doped P25 titania was prepared using the photodeposition method and characterized by TEM, ICP, XRD and UV-Vis, further tested for photocatalytic nitrate reduction and TN removal, under 20 W UV lamp irradiation. The influencing factors such as the pH values of solution, stirring gas, metal loadings, hole scavenger formic acid amount and co-doped Ag-Cu/TiO2 are investigated and discussed in detail. The experimental results after 2 h reaction indicated th
at with the increase of Cu loadings, nitrate conversion increases too, while a loading of 0.5% is optimal for highest N2 selectivity and TN(total nitrogen) removal. Using N2 as stirring gas and under acidic conditions, the N2 selectivity is lower (62%), but the highest conversion of nitrate and removal of TN can reach 36.9% and 23.2% respectively. Using CO2 as stirring gas, the highest selectivity for nitrogen 88.4% is obtained with 0.5% Cu/TiO2, 0.06 mol/L formic acid. Under the same conditions, using the prepared bimetallic titania (1%, 1∶1 Ag/Cu), the conversion of nitrate and removal of TN are 48.1%, 34.2%, and N2 selectivity is 72.2%. |
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