不同尺寸ZnO的光催化性能比较及Zn_2SnO_4修饰纳米ZnO性能评价

Photocatalytic Performance Comparison of ZnO with Different Size and Evaluation of Catalytic Performance for Nano ZnO Modified by Zn_2SnO_4

研究了ZnO尺寸及Zn_2SnO_4(ZTO)对ZnO光催化性能的影响。通过胶体自组装法和水热合成法分别制备了两种不同尺寸的ZnO,应用X射线衍射、扫描电镜等手段对催化剂进行了表征,并以λ=365nm的紫外光为光源,以甲基橙模拟染料污染物,评价了不同尺寸ZnO的光催化活性和光稳定性。结果表明,纳米ZnO拥有更高的催化活性,而微米ZnO的光稳定性相对更佳。对拥有较高催化活性的纳米ZnO辅以ZTO修饰,考察了ZTO的复合对纳米ZnO催化性能的影响。结果表明,被ZTO修饰的纳米ZnO光稳定性有较大的提升,同时催化活性比单纯纳米ZnO得到提升。实验结果结合理论研究表明,异质结构型的复合催化剂能有效分离光生电子-空穴,而ZTO与ZnO的能带位置关系决定空穴转移至ZTO,有效阻止了空穴对ZnO的腐蚀作用。研究和理论共同证实了ZTO是ZnO光稳定剂的合适选择。

Aimed at gaining insight into the effect of ZnO size and Zn2SnO4（ZTO）on photocatalytic performance of ZnO,ZnO with different size has been prepared by colloid self-assembly method and hydrothermal method.The obtained samples were characterized by X-ray diffraction and scanning electron microscopy.The photocatalytic activity and photostability of the samples were evaluated by photocatalytic degradation of methyl orange solution under UV light（λ= 365nm）irradiation.The results indicated that nano ZnO had a better photocatalytic activity,but a worse performance on photostability than micron ZnO.Nano ZnO was chosen to be modified by ZTO and compared the photocatalytic performance with pure nano ZnO.Experimental results showed that ZnO/ZTO composite material had better photocatalytic performance,including photocatalytic activity and photostability.Experimental and theoretical studies illustrated that coupling of composite material can promote the separation of electrons and holes.Band position of ZnO and Zn2SnO4 urged holes transferring to ZTO which can prevent holes corrosion ZnO.Experiments and theories indicated that ZTO was a good photo-stabilizer for ZnO.