英汉人体词“hand”和“手”一词多义认知对比研究

光催化剂利用太阳能可以充分降解生活及工业废水中的有机污染物。与其他传统方法相比，在催化效率、低毒、可回收性等性能上，有着无可比拟的优越性。半导体材料在吸收能量大于或等于其禁带宽度的光子后产生电子及空穴，经过一系列的反应，转化为具有强氧化能力的羟基自由基，来降解染料等工业废品。由于晶体结构缺陷及自身结构等特征，光生电子与空穴极易发生复合，使得产生的活性羟基自由基数量变少，减弱光催化能力。异质结构的存在，加速了电子与空穴的分离，延长电子空穴的存活寿命，对提高光催化活性有着重要的影响。

Behavior of Heterostructure for Improving Separation of Electron hole Pairs in Semiconductor Photocatalyst

Compared to other methods, photocatalyst has tremendous advantage in processing and degrading organic pollutants in sanitary and industrial waste water in the aspect of catalytic activity efficiency, non toxicy and recoverability. When the photocatalyst was radiated by UV light or visible light with the photon energy higher or equal to the band gaps of the photocatalyst, electrons and hole pairs were got and converse to vital oxidizability grains, hydroxyl radicals, so as to degrade industrial waste, such as dyes. Photogenerated electron hole pairs can be easily recombinated for the reason of crystal defects and intrinsic structues, decreasing the amount of hydroxyl radicals and lowering the photocatalytic activity. Heterostructure can accelerate the separation and prolongate the lifetime of photoinduced electron holes, which is of vital significance for the photocatalytic activity.