| 초록 |
Volatile organic compounds (VOCs) with a high vapor pressure such as formaldehyde, toluene and so on have caused increasing concern due to the adverse effects on human health. In special, health effects caused by VOCs exposure indoors are a primary issue to be solved. over the past few decades research into photocatalysis for degradation of VOCs has spanned several decades. Among the various semiconductors as photocatalysis, composite photocatalysts that consist of semiconductors with wide band gap and noble metal nanostructures have been considered to be the promising material for accessible enhancement of the efficiency in the photocatalytic process carried out in the aqueous and gas phases. In this work, we fabricated porous semiconductors with wide band gap through hydrothermal process or polymer assisted wet chemical method followed by chemical reduction of silver nanoparticles at the semiconductor surface. The morphology and structure of composite photocatalysts were studied with the use of various techniques, including transmission electron microscopy (TEM), X-ray powder diffraction analysis (XRD), photoluminescence (PL) and UV–vis diffuse-reflectance spectroscopy (DRS). The effect of metal amount on the photocatalytic activity during VOCs degradation in gas phase and methylene blue (MB) degradation in aqueous phase was investigated. Based on the comparison of photocatalytic activity, the composite photocatalysts can exhibit an improved significantly photocatalytic activity for VOCs and MB aqueous solution under ultra violet light irradiation, which can be attributed to the retarding of the charge recombination and accelerating the electron transfer from the semiconductor with wide band gap to silver nanoparticle. |
