فوتوكاتاليز؛ اصول و برخي كاربردها

Photocatalysis; principles and some applications

در اين كار، درباره ي اصول فرايند فوتوكاتاليز مطالبي ارائه گرديده است. در اين راستا، به نظريه ي نوار كه بيان كننده علت اصلي اختلاف ميان مواد رسانا، نيمه رسانا و نارساناست، اشاره شده است. در ادامه، پديده هايي كه در اثر تحريك نوري يك نيمه رسانا رخ مي دهند، مورد بحث قرار گرفته اند. همچنين ساختار برخي دگرشكل هاي 2TiO به عنوان يك نيمه رساناي مناسب براي انجام فوتوكاتاليز، مورد بررسي قرار داده شده است. در پايان، به طور مختصر برخي كاربردهاي فرايند فوتوكاتاليز به ويژه در حذف آلاينده ها از پساب ها بيان شده است.

It has been proven that the presence of catalysts enhances the rate of reactions. Also, the role of TiO2 as a photocatalyst in oxidation and photodecomposition has been studied. On the other hand, the discharge of the colored compounds in the environment causes considerable non-aesthetic pollution and serious health-risk factors. Since conventional wastewater treatment plants cannot degrade the majority of these pollutants, powerful methods for the decontamination of dyes wastewaters have received increasing attention over the past decade. In this work, the contents have been presented about the principles of photocatalysis process. In this regard, band theory has been mentioned that it is indicative of the main cause of the difference between conductive, semiconductor and insulator materials. In the following, the phenomena occurring due to the optical excitation effect of a semiconductor have been discussed. Also, the structure of some allotropes of TiO2 has been investigated. In the end, briefly, some applications of photocatalysis process, particularly in the removals of pollutants from wastewater have been expressed.