Bi_2WO_6/Bi-TiO_2复合光催化剂的制备及催化氧化甲醛性能研究

研究采用水热法制备了花状Bi_2WO_6与TiO_2和Bi-TiO_2相复合的光催化剂,并使用新型LED节能灯为光源催化氧化室内甲醛.研究发现,粉末态Bi_2WO_6显示出花状结构,但无光催化氧化活性,而将Bi_2WO_6粉末与TiO_2和Bi-TiO_2复合后,两者相互作用所形成异质结结构形态,尤其Bi_2WO_6/Bi-TiO_2催化剂,所制样品展示出更佳的催化氧化活性,而经浸渍法所得样品几乎无光催化氧化活性,催化剂随着TiO_2和Bi-TiO_2含量的增加,复合催化剂显现出不尽相同的氧化活性规律,其中Bi_2WO_6与Bi-TiO_2质量比为1∶2样品表现最佳,36 h催化氧化甲醛转化率高达92.2%,甲醛浓度低于我国居室空气中甲醛最高容许浓度,且催化剂显示出良好的稳定性及重复性.

Preparation of Bi2WO6/Bi-TiO2 Composite Photocatalysts for Catalytic Oxidation of HCHO

In this paper, the photocatalysts of Bi2WO6 and TiO2 or Bi-TiO2 was synthesized by hydrothermal methods, the photocatalysts were used to catalytic oxidation of indoor formaldehyde under the energy-saving lamp. It was found that the Bi2WO6 powder shows a flower structure, but it has no photocatalytic activity. Meanwhile, when the Bi2WO6 was mixed with TiO2 and Bi-TiO2, the structure of the heterojunction could be formed, and the samples prepared by hydrothermal method could show well activities, but the samples obtained by impregnation method showed no activities. With increasing of TiO2 and Bi-TiO2, the catalysts showed the different activities. When the mass ratio of Bi2WO6 and Bi-TiO2 was 1:2, the sample showed the highest activity and the conversion rate was as high as 92.2% with 36h. The concentration of formaldehyde was reduced below the national standard. At the same time, these catalysts showed a great stability and repeatability.