Improvement in Recycling Times and Photodegradation Efficiency of Core-Shell Structured Fe3O4@C-TiO2 Composites by pH Adjustment
Abstract
Recycling of photocatalysts is necessary for cost reduction. However, the photocatalytic properties of most reused photocatalysts deteriorate with recycled times. Thus, it is imperative to determine the dominant factor that affects the photocatalytic properties of recycled photocatalysts and find a way to improve the photocatalytic properties of recycled photocatalysts. In this work, microsized magnetic Fe3O4 powders were successfully encapsulated by carbon-doped anatase titanium (C-TiO2) by the sol-gel method to form a core (Fe3O4)-shell (C-TiO2) structure (DTF). The core-shell particles were characterized by X-ray diffraction, UV-vis diffuse reflectance spectral analysis, high-resolution transmission electron microscopy, specific surface area and magnetic properties. In addition, photocatalytic properties as well as the recovery rate were measured. It was evidenced that the as-prepared DTF powder has a larger specific surface area and a much higher dark adsorption than the nanosized C-TiO2 and commercial Fe3O4. Moreover, DTF has a high recovery rate and a first-order kinetic function k. Furthermore, it was evidenced that pH significantly affected the photodegradation efficiency of DTF. Thus, a strategy that the solution pH was modulated to a constant value of 3 was carried out, resulting in improved photodegdradation efficiency of recycled DTF.The present work could provide a new route to improving the photocatalysis efficiency and the recycles of photocatalysts
