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采用适当的化学镀工艺,通过对核层聚苯乙烯微球粒径的调制,可控合成了粒径连续可调的PS@Au核壳复合粒子,其球形度较高,无团聚,催化活性优良。利用SEM、XRD和UV-Vis,结合催化性能测试,研究了粒径对PS@Au核壳复合粒子催化性能的影响。结果表明:PS@Au核壳复合粒子较大的比表面积是其取得优良催化性能的物理本质,此外,粒径对其表面微观形貌、Au纳米粒子的生长方式及其催化性能都有显著影响。粒径较小时,核层曲率较大,Au纳米粒子呈发散式生长,表现出孤立的纳米颗粒状结构。此时,比表面积和表面能最大,催化活性最高。随着粒径增大,曲率逐渐减小,Au纳米颗粒表现出近似的薄膜状结构,比表面积和表面能逐渐降低,催化性能逐渐下降。核壳复合粒子的粒径达到400 nm时,Au纳米粒子的表面形貌开始由孤立的颗粒状结构向连续薄膜状过度。
By adopting proper electroless plating technology, PS @ Au core-shell composite particles with continuously adjustable particle size can be controlled by the modulation of the particle size of the core-layer polystyrene microspheres with high sphericity, non-agglomeration and catalytic activity excellent. The effects of particle size on the catalytic properties of PS @ Au core-shell composite particles were studied by SEM, XRD and UV-Vis combined with catalytic performance tests. The results show that the larger specific surface area of PS @ Au core-shell composite particles is the physical nature of its excellent catalytic performance. In addition, the particle size has a significant effect on the surface morphology, the growth mode of Au nanoparticles and its catalytic performance . When the particle size is small, the curvature of the nucleation layer is larger and the Au nanoparticles grow in a divergent manner, showing isolated nano-granular structures. At this point, the largest specific surface area and surface energy, the highest catalytic activity. As the particle size increases, the curvature gradually decreases and the Au nanoparticles show an approximate film-like structure. The specific surface area and surface energy decrease gradually, and the catalytic performance declines gradually. When the particle size of the core-shell composite particles reaches 400 nm, the surface morphology of the Au nanoparticles begins to change from an isolated granular structure to a continuous film.