Photocatalytic reactions involving radical chain reactions using microelectrodes
Photocatalytic reactions involving radical chain reactions using microelectrodes
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DOI：
10.1021/jp9627281
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发表时间：
1997-04-03
影响因子：
3.3
通讯作者：
Fujishima, A
中科院分区：
文献类型：
--
作者：
Ikeda, K;Sakai, H;Fujishima, A
利用微电极技术研究了乙醇在水溶液中的光催化分解机理。我们采用了部分钯覆盖的二氧化钛薄膜作为模型的金属沉积的光催化剂。我们观察到的溶解氧和H2O2的浓度变化所造成的光催化反应中存在和不存在的乙醇分别在裸露的TiO 2和Pd覆盖的表面。它清楚地表明，溶解氧消耗，甚至在乙醇的存在下，在光催化剂的氧化位点，产生H2O2。基于这些结果，我们得出结论，自由基链式反应在氧化位点进行（即，裸露的TiO 2）而不是在还原位点（即，Pd覆盖的表面）上的光催化剂。
The mechanism of photocatalytic decomposition of ethanol in aqueous solution was studied using a microelectrode technique. We employed a partially Pd-covered TiO2 film as a model for the metal-deposited photocatalyst. We observed concentration changes of dissolved oxygen and H2O2 caused by the photocatalytic reaction in the absence and presence of ethanol separately above the bare TiO2 and Pd-covered surfaces. It is clearly shown that dissolved oxygen is consumed even on oxidation sites of the photocatalyst in the presence of ethanol, producing H2O2. On the basis of these results, we conclude that radical chain reactions proceed at oxidation sites (i.e., bare TiO2) but not at reduction sites (i.e., Pd-covered surface) on the photocatalyst.