基于Si掺杂增强光吸收提升Li_(2)SnO_(3)光催化降解四环素的研究

Photocatalytic Degradation of Tetracycline by Si Doped Li_(2)SnO_(3)

在Li_(2)SnO_(3)中掺杂Si,研究了Si掺杂Li_(2)SnO_(3)对四环素的光催化降解性能。结果表明,对Li_(2)SnO_(3)进行等电子Si掺杂使其光学吸收带隙减小和光吸收系数增大,提高了对四环素的光催化降解效率。等电子Si掺杂Li_(2)SnO_(3)为纯相不规则块状固体,随着Si掺杂量的增加其晶格参数呈减小的趋势。Si掺杂使样品的光催化性能显著提高。Si掺杂量为10%的样品,在紫外光照射25 min后光催化降解效率为75.8%,约为母体的2倍。Si掺杂Li_(2)SnO_(3)的光催化降解行为满足赝一级动力学模型,拟合速率常数为0.02464 min-1。在Si掺杂Li_(2)SnO_(3)的价带顶形成的Si-O键减少了光学吸收带隙,使其光吸收能力增强。Si掺杂Li_(2)SnO_(3)的光催化降解机制,属于空穴主导型。

The photocatalytic degradation of tetracycline by Si-doped Li_(2)SnO_(3)was investigated. The results show that, through iso-electron Si doping the optical absorption band gap of Li_(2)SnO_(3)may be reduced, while its optical absorption coefficient is increased, in consequence, the photocatalytic degradation efficiency of the Si-doped Li_(2)SnO_(3)for tetracycline is enhanced. The isoelectronicaly Si-doped Li_(2)SnO_(3)is a pure and irregular mass solid, and its lattice parameters tend to decrease with the increase of Si doping amount. The photocatalytic performance of the Si-doped Li_(2)SnO_(3)was significantly improved by Si doping. Under UV irradiation for 25 min, the photocatalytic degradation efficiency of tetracycline by the Si10%-doped Li_(2)SnO_(3)is 75.8%, which is about twice as that by the simple Li_(2)SnO_(3). The photocatalytic degradation behavior of Si-doped Li_(2)SnO_(3)conforms to the pseudo-first-order kinetic model, and the fitting rate constant is 0.02464 min;. The Si-O bond formed on the top of the valence band of Si-doped Li_(2)SnO_(3)reduces the optical absorption band gap and enhances its optical absorption capacity. The photocatalytic degradation mechanism of Si-doped Li_(2)SnO_(3)is cave-dominated.