Design and Development of Second-generation TiO2 Photocatalyst Operating under Solar Beam Irradiation for the Decomposition of NOx

太阳光照射下分解氮氧化物的第二代TiO2光催化剂的设计与开发

基本信息

批准号：
09555272
负责人：
ANPO Masakazu
金额：
$ 6.85万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

In this research project, the design and development of TiO_2 photocatalysts which can absorb visible light and operate efficiently and effectively not only under ultraviolet light but also upon irradiation with visible light or solar beam for the decomposition of NO into N_2 and 0_2 were carried out. Until now, photocatalytic reactions involving TiO_2 photocatalysts for the decomposition reaction of nitrogen oxides (NOx) in the atmosphere are known to proceed only under irradiation of TiO2 photocatalysts with ultraviolet light having shorter wavelength than 380nm, allowing the use of 3% of solar beam. In order to use solar beam more efficiently, we have elucidated the modification of TiO_2 photocatalyst by applying the advanced metal ion-implantation with various transition metal ions such as Cr highly accelerated by high voltage. A combination of such metal ion-implantation and the subsequent calcination of the catalyst in oxygen at around 723 K enables a large shift in the absorption bands of TiO_2 toward visible-light regions, its extent depending on the amount of Cr ions implanted. Such Cr ion-implanted TiO_2 catalysts successfully decompose NO into N_2, 0_2 and N_2O even at 275 K under irradiation with visible light longer than 450nm. Furthermore, the reaction proceeded at exactly the same rate to that of the unimplanted TiO_2 catalysts under band-gap UV light irradiation. Under outdoor solar light irradiation at ordinary temperatures, the Cr ion-implanted TiO_2 catalyst exhibited photocatalytic reactivity several times higher than the original unimplanted TiO_2 photocatalyst. It can be said that present research has opened the way to many innovative possibilities, significantly to address urgent environmental problems, and can also be considered an important breakthrough in the utilization of solar energy.

在该研究项目中，TIO_2光催化剂的设计和开发可以吸收可见光并有效地操作，不仅在紫外线下，而且在用可见光或太阳能光束进行照射下，将NO分解为N_2和0_2。到目前为止，已知涉及涉及TIO_2光催化剂的光催化反应，用于大气中氮氧化物（NOX）的分解反应，仅在Tio2光催化剂的带有紫外线的Tio2光催化剂的辐射下才能进行，其波长比380nm较短，从而允许使用3％的Solar Beb。为了更有效地使用太阳束，我们通过将高级金属离子植入物与各种过渡金属离子（例如高压高度加速的Cr）施加了高级金属离子植入术，从而阐明了TiO_2光催化剂的修饰。这种金属离子植入术和随后在氧气中催化剂在723 k处的钙化的结合使TiO_2的吸收带向可见光的灯区域发生了很大的转移，其程度取决于所植入的CR离子的量。这种cr离子植入的TIO_2催化剂即使在辐照下，在275 K下，仍将NO分解为N_2、0_2和N_2O，可见光长于450nm。此外，该反应以与带隙紫外线光照射下未植入的TIO_2催化剂的速率完全相同的速率进行。在普通温度下的室外太阳光照射下，CR离子植入的TIO_2催化剂表现出比原始未植入的TIO_2光催化剂的光催化反应性。可以说，目前的研究为许多创新的可能性开辟了道路，可以大大解决紧急环境问题，也可以被认为是太阳能利用的重要突破。