ZnS-CdS/ZnO의 합성 및 가시광에서의 광촉매 활성

Abstract

ZnO has attracted attention as a multifunctional material suitable for a variety of applications due to its unique properties and high chemical stability. Recently ZnO, an n-type semiconductor, has emerged as one of the most promising photocatalyst in the degradation and complete mineralization of environmental pollutants. Although remarkable development has been made in recent years for the photocatalysts working under ultraviolet light, there are limits for the photocatalysts to be applied under visible light. Thus, in this study, the visible light responsive ZnS-CdS/ZnO materials were successfully fabricated using the chemical precipitation method and used as photocatalysts in photocatalytic degradation of Rhodamine B. Combination of semiconductors such as metal oxided (ZnO) and metal sulphides (ZnS and CdS) as photocatalysts with visible light can be used for degradation of a wide range of dye contaminations. The CdS was used as a photosensitizing agent to activate ZnO due to its narrow direct band gap and ZnS was also deposited on the ZnO to increase the efficiency and stability of the system. The prepared samples were characterized by X-ray diffraction and UV-vis diffuse reflectance spectroscopy. The prepared samples show high crystallinity. The absorption spectrum extends to the visible light range. As expected, the experiments of photocatalytic degradation of Rhodamine B show that ZnS-CdS/ZnO exhibits much higher photocatalytic activity compared to pure ZnO sample under visible light irradiation.