铋及钴掺杂TiO2陶瓷负载膜的制备及光催化性能

以钛酸四丁酯为钛源,Bi(NO₃)₃·5H₂O为铋源,Co(NO₃)₂·6H₂O为钴源,采用溶胶-凝胶法在陶瓷基片上分别制备了应用于固定式光催化反应器的Bi-TiO₂复合膜及Co-TiO₂复合膜。研究了涂膜方式及煅烧升温速率对膜表面形态的影响,并以甲基橙溶液为目标降解物,对比了旋涂法及浸渍提拉法制备的薄膜在不同升温速率下的光催化活性。通过热分析仪(TG-DSC)、X射线衍射仪(XRD)和扫描电镜(SEM)等测试手段分析了掺杂薄膜的结构。结果表明,采用旋涂法制备的薄膜与陶瓷基体结合较为紧密,而浸渍提拉法制备的薄膜催化活性较高。当煅烧温度为500 ℃,升温速率为10 ℃/min时,其对甲基橙的降解率较高。当摩尔比为0.010时Bi-TiO₂复合膜的催化活性较佳,100 min光降解甲基橙比率达到8.10%。钴或铋掺杂TiO₂均可提高TiO₂催化剂的光催化活性,Bi-TiO₂膜的催化活性优于Co-TiO₂膜。

Preparation and Photocatalytic Performance of Bi and Co Doped TiO2 Ceramic Films

Bi-TiO₂ and Co-TiO₂ composite films applied on the fixed photocatalytic reactor were prepared on ceramic substrate by sol-gel method, with the titanium source of tetrabutyl titanate, the Bi source of Bi(NO₃)₃·5H₂O and the Co source of Co(NO₃)₂·6H₂O. The effects of coating processes and heating rates of calcination on the surface morphology of the films were studied.The photocatalytic activity of the films prepared by spin-coating method and dip-coating method at different heating rates was compared with methyl orange solution. The structures of the films were conducted by TG-DSC, XRD and SEM tests. The results show that Bi or Co ion doping are beneficial to the phase transformation of amorphous TiO₂ to anatase TiO₂.The results show that the films prepared by spin-coating method are closely bonded to the ceramic substrate, while the films prepared by dip-coating method have higher catalytic activity. When the calcination temperature is 500 ℃ and the heating rate is 10 ℃/min, the degradation rate of methyl orange is higher. When the atom mole ratio is 0.010, the photodegradation of methyl orange catalyzed by the Bi-TiO₂ films is up to 8.10% after 100 min reactions. Co or Bi ion-doped process are able to improve the photocatalytic activity of the TiO₂ catalyst and the catalytic activity of Bi-TiO₂ films is better than that of Co-TiO₂ films.