【摘要】 用籽晶法,以甲醛为还原剂、3-氨丙基三乙氧基硅烷(APS)为改性剂,在Ag[(NH3)2]+溶液中制备α-Fe2O3/Ag核壳结构复合粉体。采用XRD、TEM和EDX对样品进行表征,系统研究了APS改性剂、醇水比等对复合纳米颗粒包覆效果及性能的影响;并用吡啶(Py)为探针,研究了α-Fe2O3/Ag核壳纳米颗粒作为拉曼衬底时的拉曼增强性能(SERS)及稳定性。结果表明,当APS=0.75%(质量),醇水比=5∶1时,α-Fe2O3/Ag核壳结构纳米颗粒的平均粒径为65nm左右,包覆完整,分散均匀,位于1010cm-1和1038cm-1处吡啶信号显著增强,具有良好的SERS活性。在空气中放置一段时间后仍能保持较好的增强效果,稳定性好。更多还原

【Abstract】 With the seeding method,α-Fe2O3/Ag core-shell composite powders were prepared by the reduction of Ag[(NH3)2]+ with formaldehyde as reductant,and 3-aminopropyl triethoxysilane as additive.3-Aminopropyl triethoxysilane (APS) acted as a "bridge" to connect α-Fe2O3 and Ag particles.The obtained nanocomposites were characterized by X-ray diffraction (XRD),transmission electron microscope (TEM) and energy-dispersive X-ray spectrometry (EDX).The influences of concentration of APS,volume ratio of alcohol to water on the coating effect and performance of nanocomposites were investigated.With pyridine (Py) as a molecule probe,Raman spectroscopy (SERS) properties and stability of the α-Fe2O3/Ag core/shell composite particles were studied.The results showed that the obtained α-Fe2O3/Ag composites were coated completely,well-dispersed and the average sizes were approximately 65 nm,when the dosage of APS was 0.75%(mass) and the volume ratio of alcohol to water was 5∶1.By coating Ag layer,the intensities of SERS were enhanced at 1010 cm-1 and 1038 cm-1.Especially,the signals of Py absorbed on α-Fe2O3/Ag substrate were greatly increased at 1038 cm-1.And this substrate was fairly stable after being placed in air for one month.更多还原