三种不同晶型二氧化钛的制备及光催化性能研究

Preparation of Three Types of Titanium Dioxides with Different Crystallite and the Photoreactivity

分别以Ti(SO4)2和TiCl4为原料,通过水热pH值的控制,批量制备了片状的锐钛矿(AT)、棒状的金红石(RT)和菱形的板钛矿型(BT)TiO2.其中,AT具有最小的晶粒尺寸(约10nm),其次为RT(30—50nm),而BT具有最大的晶粒尺寸(50—70nm).固体漫反射显示出AT、BT和RT对光响应的阀值分别为375nm、385nm和415nm.其中,AT在紫外区显示出最强的光吸收能力.以阴离子活性染料X3B为目标分子的光催化降解实验结果显示,3种催化剂的光活性次序为AT>RT>BT,这与它们对X3B的吸附能力一致.文章对这产生TiO2光活性差异的原因进行了讨论.

Anatase （AT） nanoplates, club-shaped rutile （RT） and prism-shaped brookite （BT） TiO2 were prepared on a large .scale through hydrothermal treatment of Ti（SO4）2 or TiCI4 at certain pH. The mean particle size of the prepared AT was about 10 nrn, the smallest one among the three types of TiO2, compared with 30--50 nm of BT and 50--70 nm of BT. The maximum responsive wavelength of AT, BT and RT was to about 375, 385 and 415 nm, respectively, and AT shows the strongest absorption in the range of UV light. The photooxidation activity evaluated from the photocatalytic degradation of X3B, an anionic organic dye, revealed that the relative photoreactivity of the TiO2 samples was as follows： AT〉RT〉BT, which is consistant with the adsorption ability of the catalysts. The reasons that caused the differences in photoreactivity among the three types TiO2 were also discussed.