用4种浓度不同的硝酸银溶液浸渍活性炭纤维制备载银活性炭纤维样品(ACF-1、ACF-2、ACF-3和ACF-41。电镜扫描结果表明纤维表面附着的银颗粒直径随硝酸银浓度的升高而增大,结晶点位数量随浓度的升高而增多,且较多地分布在做孔边缘和交界处。电感耦合等离子体质谱仪分析表明各炭纤维载银量随浓度的升高而增大,并呈近似线性关系。汞吸附实验表明炭纤维负载银后对汞的吸附性能均得到提高,其提升程度与纤维表面的载银量有显著关联,其中ACF-4的单位汞吸附量约为原始活性炭纤维的33倍。x射线光电子能谱分析表明由于载银过程中纤维表面的氧(--O)物种增多,产生Ag—O—C配位键,增强了银粒子与纤维基体的相互作用,因而提高了纤维表面对汞的吸附势能和吸附容量。
The virgin viscose activated carbon fiber (ACF) was impregnated with four different concentrations of silver nitrate solutions. These four silver-loaded ACF samples were ACF-1, ACF-2, ACF-3 and ACF-4 respectively. The scanning electron microscopy (SEM) micrographs showed that the silver particles were mainly distributed in the edge and at the junction of microporous of ACF surfaces, the silver particle size and the number of active points on ACF increased with higher concentration of silver nitrate solutions. The inductively coupled plasma-mass spectrometry (ICP-MS) results indicated the content of silver-loaded on ACFs increased with higher concentration of silver nitrate solutions, and there was approximate linear relation between them. The characteristics of mercury adsorption by silver-loaded ACFs sorbents were experimentally measured. The results show that the adsorption performance of silver-loaded ACFs is significantly improved than virgin ACF. The Hg uptake of ACF-4 is about 33 times larger than virgin ACF. It is also suggested that the concentration of silver has influence on the adsorption ability of ACF samples. X-ray photoelectron spectroscopy (XPS) spectra results suggest that Ag--O--C forms on the surface of ACFs since oxygen (--O) species increases during the process of silver loaded, which leading nanometer silver adsorbed on ACF more steady. As a result, Hg adsorption potential and adsorption capacity are enhanced.