| 摘要 |
<p>When a nitrogen oxide (nitrogen monoxide) is contacted with or approaches titanium dioxide functioning as a photocatalyst and compounded with either an amphoteric metal oxide having basic sites (alumina, etc.) or a basic metal oxide (barium oxide, strontium oxide, etc.), the nitrogen monoxide is oxidized into nitrogen dioxide (gas) with •OH which is an active oxygen species generated by the titanium dioxide upon irradiation with light. Since alumina is an amphoteric metal oxide and barium oxide and strontium oxide are basic metal oxides, oxygen atoms of these metal oxides function as basic sites for acidic gases. Consequently, the nitrogen dioxide, which is an acidic gas because of its molecular structure, is attracted by and chemically bonded to these oxygen atoms. Thus, the nitrogen dioxide is held on the metal oxide at positions close to the titanium dioxide, serving as a photocatalyst.</p> |
