光催化剂SnC_2O_4的合成及其可见光催化活性

Synthesis of Photocatalyst SnC_2O_4 and Its Visible Photocatalytic Activity

以(NH_4)_2C_2O_4为沉淀剂,采用直接沉淀法合成了新型光催化剂SnC_2O_4粉末。通过X射线粉末衍射、扫描电镜、紫外-可见分光光度计及荧光分光光度计等手段对样品的物相结构、微观形貌以及光吸收性能等进行了分析表征。结果表明:所制备的样品为单斜白钨矿型SnC_2O_4,空间群为C2/C(15)。样品的微观形貌为不规则多面体,其禁带宽度为3. 44 e V。光致发光光谱表明样品内部可能有大量的氧空位和其它缺陷。以甲基橙为模拟染料废水对SnC_2O_4样品的光催化活性进行了评价。当甲基橙染料的浓度为40 mg/L,SnC_2O_4光催化剂的投加量为40 mg/50m L时,在模拟可见光照射下,甲基橙降解率可达99. 1%,且光催化降解反应符合一级动力学方程。此外,通过引入活性物种捕获剂证明·O-2在光催化降解甲基橙反应中起重要作用。

A novel type of photocatalyst SnC 2O 4 powder was synthesized by direct precipitation method with(NH 4)2C 2O 4 as precipitant.The phase structure,microstructure and optical absorption properties of the sample were characterized by X-ray powder diffraction,scanning electron microscope,UV-Vis spectrophotometer and fluorescence spectrophotometer.The results show that the prepared sample is monoclinic SnC 2O 4 with space group C2/C(15).The micromorphology of the sample exhibits irregular polyhedron.The average band gap is estimated to be 3.44 eV.The photoluminescence spectrum suggests that SnC 2O 4 sample might have a large number of oxygen vacancies and some other defects.The photocatalytic activity of SnC 2O 4 was evaluated with methyl orange as a simulated dye wastewater.When the concentration of methyl orange is 40 mg/L and the dosage of SnC 2O 4 photocatalyst is 40 mg/50 mL,the degradation rate of methyl orange can reach to 99.1%under simulated visible light irradiation,and the photocatalytic degradation reaction accords with the first-order kinetic equation.In addition,·O-2 has been proved to play an important role in the photocatalytic degradation of methyl orange by the introduction of active species capture agent.