수산화 암모늄을 이용한 실리카/은 나노입자의 제조와 광촉매 효과에 대한 연구

Abstract

Catalytic capabilities of noble metal nanoparticles, such as gold and silver, have drawn many research interests due to their optical properties and localized surface plasmon resonance (LSPR) effect. Noble metal nanoparticles are able to absorb the light to form conduction electrons and excited electrons can contribute to converting the solar energy to chemical energy by means of photocatalytic reactions. It has been studied the inorganic/metal composite nanoparticles, such as semiconductor catalytst TiO2, utilized to improve the performance of catalytic performance. Recently, insulating solids/metal composite nanoparticles have been studied photocatalytic effects performing by distinct mechanism of semiconducting photocatalysts. In this study, preparation of silica/silver nanoparticles and their photocatalytic performance was conducted among various properties. Silver nanoparticles on the silica nanoparticles were synthesized via alcohol reduction process in different amount of NH4OH. NH4OH was used to control the size and reaction rate for the formation of silver nanoparticles and silica nanoparticles. Silica nanoparticles were prepared as support by using Stöber method and the surface of silica nanoparticles was modified with thiol groups as chemical binders to immobilize silver nanoparticles. The crystalline structure of silica/silver nanoparticles could be obtained after annealing process at 400°C. Silica/silver nanoparticles exhibited photocatalytic performance as it able to adsorb on the surface of methylene blue dye and decompose it. It has been shown that the time of decomposition of methylene blue was decreased in the influence of the size and the number of silver nanoparticles.