具螢光特性的磁性氧化鐵中空球之合成與特性分析

Synthesis and Characterization of Magnetic Iron Oxide Hollow Spheres with Fluorescent Properties

本研究結合噴霧熱裂解製程及溶膠凝膠法，在微米尺寸的四氧化三鐵(Fe3O4)中空球上披覆羅丹明6G(R6G)摻雜的二氧化矽(SiO2)殼層，合成Fe3O4-SiO2-R6G(FSR)複合結構中空球，摻雜濃度由5´10-4 M至5´10-2 M。樣品的晶體結構、微觀結構、磁性及發光特性以X光繞射儀(XRD)、掃描式電子顯微鏡(SEM)、穿透式電子顯微鏡(TEM)、光致發光光譜儀(PL)、雷射掃描共軛焦顯微鏡及震動式樣品磁力計(VSM)進行分析。實驗結果顯示，以此兩段式製程所製備的FSR中空球，殼厚隨著所摻雜之R6G濃度提高而增加，為23奈米至50奈米。球殼包含兩層結構，內層由Fe3O4結晶顆粒組成，外層為SiO2非晶膜。樣品均具有鐵磁性，飽和磁化強度隨所摻雜之R6G濃度提高而下降，最高可達50 emu/g。樣品在波長488奈米的雷射光激發下可發出波長550奈米之螢光，放射強度隨著所摻雜的R6G濃度增加而增強。此外，根據發光特性指出殼層中的R6G為單體形式。

In this study, Fe3O4-SiO2-R6G (FSR) composite structure hollow spheres were developed by combining the spray pyrolysis process and the sol-gel method. First, micron-sized Fe3O4 hollow spheres were prepared, then coated with R6G-doped SiO2 shells, with a doping concentration ranging from 5´10-4 M to 5´10-2 M. The crystal structure, microstructure, magnetic properties, and luminescent properties of the composite were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), photoluminescence spectrometer (PL), laser scanning Confocal microscope and vibrating sample magnetometer (VSM). It demonstrated that the shell thickness increases with the concentration of R6G, ranging from 23 nm to 50 nm. The spherical shell has a two-layer structure, the inner layer is composed of Fe3O4 crystalline particles, and the outer layer is SiO2 amorphous film. The samples are all ferromagnetic, and the saturation magnetization can reach up to 50 emu/g, which decreases with the increase of doped R6G concentration. The sample emits fluorescence with a wavelength of 550 nm when excited by light with a wavelength of 488 nm, and the emission intensity increases as the concentration of doped R6G increases. In addition, the R6G in the shell was indicated to be in the form of a monomer according to the luminescent properties.