PHOTOCATALYTIC ACTIVITY OF TIO2 POWDERS SUSPENDED IN AQUEOUS SILVER-NITRATE SOLUTION - CORRELATION WITH PH-DEPENDENT SURFACE-STRUCTURES
PHOTOCATALYTIC ACTIVITY OF TIO2 POWDERS SUSPENDED IN AQUEOUS SILVER-NITRATE SOLUTION - CORRELATION WITH PH-DEPENDENT SURFACE-STRUCTURES
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DOI：
10.1021/j100297a017
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发表时间：
1987-06-18
影响因子：
--
通讯作者：
KAGIYA, T
中科院分区：
文献类型：
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作者：
OHTANI, B;OKUGAWA, Y;KAGIYA, T
在室温下在Ar下研究了悬浮在AgNG 3溶液中的金红石和金红石TiO 2粉末的光催化（n> 300 nm）活性。产生O2和Ag金属的光催化反应的初始速率强烈地依赖于悬浮液的pH，即，其随着pH降低而降低，分别在pH< 2的情况下对于金红石和pH< 5的情况下对于金红石变得可忽略不计。在黑暗中吸附在TiO 2表面上的Ag+的量随着pH从8降低到2而降低。TiO 2活性的pH依赖性主要归因于Ag+吸附;通过bothanase和金红石TiO 2的光催化反应的初始速率与表面吸附的Ag+的量成比例。通过电位滴定法对TiO 2粉体表面羟基的表征表明，降低pH值会使中性羟基质子化为带正电荷的羟基，从而抑制Ag+的吸附。
Photocatalytic („> 300 nm) activity of anatase and rutile Ti02 powders suspended in AgNG3 solution was investigated at room temperature under Ar. The initial rate of the photocatalytic reaction producing 02 and Ag metal strongly depended upon the pH of suspension, ie, it decreased with decreasing pH, becoming negligible at pH< 2 with anatase and pH< 5 with rutile, respectively. The amount of Ag+ adsorbed on the Ti02 surfaces in the dark decreased with decreasing pH from8 to 2. The pH dependence of Ti02 activity was attributed predominantly to the Ag+ adsorption; the initial rates of the photocatalytic reactions by bothanatase and rutile Ti02 were in proportion to the amount of surface-adsorbed Ag+. The characterization of surface hydroxyl groups on the Ti02 powders by means of potentiometric titrationof the aqueous suspensions revealed that decreasing the pH causes the protonation of neutral hydroxyl groups into positively charged ones, which inhibits the Ag+ adsorption.