Investigation of Photo-degradation mechanism of semiconductor-organic material interface

半导体材料现在在各个领域都非常重要。它们的一些性质如光敏性还没有得到很好的理解。我们研究了有机材料的光降解，其中包括半导体材料，如小粉末。由于我们对光激发的半导体-液体界面的电化学现象有了足够的经验，因此采用了光电化学技术。首先，用有机层绝缘的半导体电极测量了半导体表面的光催化活性。光电流在恒定施加的通孔随着照射时间的增加，表明光激发的空穴中形成的价带提取的电子从有机分子。因此，有机分子被氧化和降解。其次，我们研究了一种新的光致沉降法来评价半导体粉体表面包覆疏水有机分子后的光催化活性。从光致下沉速率的光催化活性已估计。

Semiconductor materials are now very important in various fields. Some of their properties such as photosensitive properties have not been well understood.We have investigated photodegradation of organic materials in which semiconductor materials such as small powders are included. Since we have enough experiences for electrochemical phenomena of photoexcited semiconductor-liquid interfaces, photoelectrochemical techniques have been employed. At first, photocatalytic activity of semiconductor surface was measured by using of semiconductor electrode insulated with oeganic layers. Photocurrent at the constant applied vias increased with irradiation time indicating that photoexcited holes formed in the valence band extracted electrons from the organic molecules. Therefore, the organic molecules were oxidized and degraded. Secondly we studied a new method named as photosinking for estimation of photocatalytic activity of semiconductor powders which were coated with some organic molecules with hydrophobic character. From the photosinking rate photocatalytic activity has been estimated.