触媒OnTheWebロゴマーク
一般社団法人 触媒学会

記事情報

PDF PDF1.6 MB(閲覧回数：826回)
巻・号 3巻3号 ページ 235
記事分類・特集 原報
題目(和文)酸化亜鉛の光触媒能の研究
著者藤田勇三郎 
要旨(英文)The effect of illumination on the oxygen adsorbed on various zinc oxide samples was investigated using near ultra-violet light. Reversible photodesorption of oxygen was found to occur on highly outgassed zinc oxide which was prepared by igniting zinc carbonate and denoted as ZnO I. On the other hand, the photoresponse turned to be an irreversible photoadsorption when the zinc oxide sample was subjected to oxidation in an oxygen atmosphere. In either case, the effective wave length of the light nearly coincided with that of the characteristic absorption of zinc oxide. Initial rates of these photoresponses were observed against light intensity, oxygen pressure and temperature.The mechanism of the photoresponse was investigated after Wolkenstein's method with particular interest in the reversal effect, i. e., photoresponses were discussed in connection with recombination processes of optically created charge carriers through the surface level of adsorbed oxygen. Thus, it became apparent that the relative height of Fermi level of a given zinc oxide sample to the surface level of adsorbed oxygen is important as to whether photodesorption or photoadsorption should appear on illumination. Additional experiments were carried out on the basis of the mechanism using zinc oxide samples doped with impurities such as alumina or lithium oxide, and found to be compatible with the theoretical expectation.The effect of illumination on the catalytic oxidation of carbon monoxide was investigated. A zinc oxide sample supplied by Kanto Kagaku K.K. was used throughout experiments, the sample being denoted as ZnO 2. Photocatalytic oxidation of carbon monoxide was found to occur with the light near ultra-violet at 100-200℃ while no reaction was perceptible in the absence of light in this tem-perature interval. The rate of the photocatalytic reaction was expressed by ν= k PO2 0.6 Pco0. The temperature coefficient was found to be 2.3 kcal. The photocatalytic oxidation of carbon monoxide was described to appear via photoenhanced adsorption of oxygen on the catalyst surface since the photoeffect on the present ZnO 2-O2 system turned out always to be adsorption. Neither outgassing nor reduction in a carbon monoxide atmosphere below 500℃ gave rise to photodesorption in contrast with ZnO I. The pretreatment of the zinc oxide sample was found, however, to affect the photocatalytic activity toward the oxidation of carbon monoxide. Based on such photokinetic behavior, photo-catalytic mechanism of the oxidation of carbon monoxide was postulated and discussed.The liquid phase oxidation of isopropyl alcohol was investigated in the presence of ZnO 2. The oxidation reaction conducted at 65℃ was markedly accelerated when illuminated by the light near ultra-violet, the products being exclusively acetone and hydrogen peroxide. The photocatalytic ultra-violet, the products being exclusively acetone and hydrogen peroxide. The photocatalytic avtivity was sensitively dependent again on the pretreatment of the zinc oxide sample. On outgassed ZnO 2, the consumption of oxygen took place on illumination while it stopped on interrupting the light. On untreated ZnO 2, on the other hand, the consumption of oxygen did not stop on interrupting the light. Moreover, it continued rather acceleratingly with the progress of the reaction. This apparently peculiar phenomena were interpreted as that adsorbed oxygen produced by the decomposition of hydrogen peroxide takes part simultaneously in the chain initiation of the reaction in the case of untreated ZnO 2 while photoadsorbed oxygen was the sole chain initiator on outgassed ZnO 2. Adsorbed oxygen produced from the decomposition of hydrogen peroxide was considered to prevail in a later stage of the reaction, hence giving rise to dark reaction.
発行年月日2016-12-01 公開日2016-12-01
パーマリンク https://catsj.jp/jnl/pageview?articlecd=0303023500j
塩酸アニリンならびにその誘導体の固相および融解相中における分子内重水素交換反応
3巻3号へ戻る
よく読まれているページ
2022年12月24日 ～ 2023年03月24日

 

新 進 触 媒 研 究 者 に 告 ぐ

(117回)

「ゼオライト触媒上に吸着した分子のIR観測による反応素過程の解明」

(63回)

デルフト工科大学　化学工学科　Catalysis Engineeringグループ

(58回)

上に戻る
あなたの検索履歴
 参照触媒の手引き（第7版） 
 正会員・学生会員の方は、
 下のバナーから閲覧・ダウンロード
 ができます。 参照触媒の手引き（第7版）
 触媒技術の動向と展望 
触媒年鑑

2022 2021 

バックナンバー
検索ワードランキング

(27823件/のべ数：7824136）

  1. ゼオライト（3070回）
  2. 二酸化炭素（2943回）
  3. 水蒸気改質（2846回）
  4. アンモニア（2820回）
  5. 白金（2782回）
  6. 光触媒（2667回）
  7. メタン（2663回）
  8. 水素化（2616回）
  9. CO2（2567回）
  10. 触媒討論会（2545回）
ダウンロード総数

(全145413件）

  1. 貴金属合金触媒（1999回）
  2. 触媒OnTheWeb Hacks─「触媒」誌のウェブサイトを使う─（1648回）
  3. 光触媒はどこまでわかったか（1056回）
  4. 住友化学の研究開発戦略―触媒研究と高機能材料開発―（1030回）
  5. 触媒の活性を徹底的に使い切るための技術（984回）
  6. ゼオライト触媒によるクメン接触分解（914回）
  7. 酸化亜鉛の光触媒能の研究（826回）
  8. 光触媒反応（812回）
  9. 急速加熱急速冷却法による十面体形状アナタース型酸化チタンの気相合成（765回）
  10. 平成25年度触媒学会表彰（689回）
『触媒技術の動向と展望2018』訂正

触媒技術の動向と展望の「特別寄稿」および「1-ヘキセン」の記事で編集ミスがありましたので、修正版を掲載いたします。

Copyright (C) 1959-2023 Catalysis Society of Japan (触媒学会) All rights reserved.｜本サイトの内容の無断転載を禁じます