Executive Summary : | Photocatalytic organic synthesis has emerged as one of the most promising technologies to direct conversion of solar energy into chemical energy. An ideal photo-catalyst needs to extend the maximum absorption wavelength to 800 nm, because only ~ 40% of sunlight is visible light. Over last few decades, a large number of visible light catalysts have been reported and applied, but solar energy cannot be used very effectively by using heterogeneous semiconductor catalysts. In this regard, colloidal quantum dots (QDs) have great potential to behave as efficient light catalyst because of their structures, precisely controlled compositions, and surface properties. They possess high photo-stability, high absorption cross-section with high molar extinction coefficient and exhibit tunable optical property. They exhibit tunable optical properties due to quantum confinement effect. The emission wavelengths of the colloidal quantum dots can be tuned by adjusting their size and shape. Typically their sizes range between 2 to 20 nm. Because of their size and surface effects, they possess potentially good photo-chemical stability. Initially, quantum dots were added with other semiconductor catalysts and used as heterogeneous catalysts in the reaction systems. Normally, QD-based photo-catalysts were mainly used for H₂ evolution, CO₂ reduction and then extended to organic synthesis. There are several reports which indicate superior catalysis quality of colloidal quantum dots than conventional catalyst. Earlier studies indicate that the QDs also have the potential to reuse several times without any loss of catalytic activity and so it has great potential in visible-light-catalyzed organic reactions. Hence, our aim will be to develop detail knowledge on QDs about their size, shape, composition and surrounding environment-dependent exciton dynamics and energy transfer, which eventually will be crucial to develop efficient systems for photo-catalysis applications. Here, in this project, our plan is to exploit these characteristics to design QDs with tailored properties. We will then apply these synthesized environment friendly QDs for Photocatalytic organic transformations in different organic transformations, which we will elaborated one after another in detail in this proposal. |