CeO_2-TiO_2/[CoW_(12)O_(40)]^(5-)-HTLC的制备及光催化性能

Preparation and Photo - catalytic Performance of TiO_2 - CeO_2 /[CoW_(12)O_(40) ]^(5-) Pillared Hydrotalcite

为了克服杂多酸易溶于极性溶剂,较难回收重复使用的缺点,采用共沉淀法制备了镁铝水滑石;并以硝酸根型水滑石作为前体,通过插层组装合成了杂多阴离子[CoW12O40]5--HTLC;再采用微乳液法将CeO2掺杂的TiO2负载到[CoW12O40]5--HTLC上,焙烧后得到CeO2-TiO2/[CoW12O40]5--HTLC光催化剂。采用XRD、FT-IR、SEM-EDS和UV-Vis漫反射光谱等手段对催化剂进行了表征;以甲基橙为模拟污染物,考察了催化剂样品的光催化性能。实验结果表明:CeO2掺杂TiO2复合粒子在可见光区吸光性能高于TiO2;CeO2掺杂TiO2与杂多阴离子[CoW12O40]5-有协同光催化作用,CeO2-TiO2/[CoW12O40]5--HTLC光催化剂对可见光的吸收大大增强。经模拟日光照射2 h,15%(CeO2-TiO2)/5%[CoW12O40]5--HTLC催化剂对甲基橙的脱色率达到93%。

MgAl- hydrotalcite was prepared by coprecipitation. With the NO3- -HTLC as precursor, hetero- polyanion [CoW_12 O_40 ]^5- _ HTLC was synthesized by intercalating assembly. Moreover, CeO2 doped TiO2 was loaded on the surface of the pillared hydrotalcite via microemulsion method. After calcination, CeO2 -TiO2/ [ CoW_12 O_40 ]^5- _ HTLC photocatalyst was obtained at last. The catalyst was characterized by means of XRD, l^r -IR, SEM -EDS and UV -Vis diffuse reflectance spectroscopy. With methyl orange as the aim pollutant, the photocatalytic performance of the catalyst sample was investigated under simulated sunlight irradiation. The ex- perimental results show that： the absorption performance for visible light of the CeO2 -TiO2 composite particles was higher than that of TiO2. There is synergistic photocatalysis between the CeO2 - TiO2 and heteropolyanion [CoW_12 O_40]^5-. The absorption for visible light of the CeO2 -TiO2/ [CoW_12 O_40]^5-- _ HTLC photocatalyst is greatly enhanced. Under simulating sunlight irradiation for 2 h, the decolorization degree for methyl orange of 15% （ CeO2 - TiO2 ）/5% [CoW_12 O_40]^5- _ HTLC catalyst reaches 93%.