氟铜共掺杂TiO_2空心微球的制备及可见光催化性能

Preparation of fluorine and copper co-doping TiO_2 hollow microspheres and its visible light photocatalytic performance

以钛酸四丁酯为钛源、氢氟酸为氟源、硝酸铜为铜源,乙醇为溶剂,采用蒸汽热法制备氟铜共掺杂的TiO_2空心微球,采用SEM、XRD、UV-Vis、BET等对氟铜共掺杂的TiO_2空心微球的形貌特征、晶相结构、吸光性能及氟、铜的存在形式进行表征,以阳离子蓝的光催化降解为目标反应,评价其光催化活性。结果表明:氟铜共掺杂的TiO_2空心微球主要通过水蒸气产生的气泡为模板获得,氟铜共掺杂增大TiO_2的比表面积,其中TiO_2以锐钛矿存在,Cu^(2+)进入TiO_2晶格中,大部分F以化学吸附态存在于TiO_2的表面形成≡Ti—F基团,少量F进入晶格内部。相比纯TiO_2空心微球,氟铜共掺杂的TiO_2空心微球的光催化活性明显提高,用氙灯模拟可见光,对初始浓度为20 mg/L的阳离子蓝溶液进行光催化降解,30 min后其降解率达到99.8%。

F and Cu co-doping TiO_2 hollow microspheres were synthesized via steam heat method,using tetrabutyl orthotitanate as Ti source,hydrofluoric acid as F source,cupric nitrate as Cu source and ethanol as solvent.The structure and properties of the resulting samples were characterized by SEM,XRD,UV-Vis,BET and so on.Photocatalytic degradation of cationic blue was used as a probe reaction to evaluate their photocatalytic activity.The results indicate that the F and Cu co-doping TiO_2 hollow microspheres are anatase phase structure,Cu^(2+) enters into the TiO_2 lattice,the fluorine atoms mainly distributed on the surface of TiO_2,and exist in forms of chemical-adsorption,the F and Cu co-doping TiO_2 hollow microspheres are achieved by the template of water vapor bubbles.The F and Cu co-doping TiO_2 hollow microspheres increase the specific surface area of TiO_2.Compared to pure TiO_2 hollow microspheres,the F and Cu co-doping TiO_2 hollow microspheres show much higher degradation efficiency under xenon lamp irradiation,and the degradation rate of which can be up to 99.8% during the photodegradation of cationic blue with the initial concentration of 20 mg/L for 30 min.