Abstract:
This article reports the systematic photoluminescence study of the various contents of gold nanocomposites in polyvinyl alcohol (PVA) films. The variations in the gold content in PVA film were 0.2, 0.5, 1.0, and 1.5 wt%. All the samples were excited at two selected wavelengths; those are at 400 nm and 532 nm. On exciting the gold-PVA nanocomposite films at 400 nm the photoluminescence was observed in the region of 430-500 nm in comparison to pure PVA films that show an emission at 400 nm. However, on exciting the gold-PVA nanocomposites at 532 nm, the emission was observed at 560-650 nm with a long tail till 700 nm that is unlike the pure PVA films that do not show any emission peak in this region. This suggests that emission between 430 and 500 nm regions is due to the coordination of PVA with gold nanoparticles because PVA has an emission at 400 nm. However, the emission peak between 560 and 650 nm is entirely due to the gold nanocomposite particle. The peak also shows a smaller red-shift that is usually with the increasing nanoparticles size with the increasing content in the PVA films. The formation of gold nanoparticles was justified by X-ray diffraction (XRD) analysis which is further supported by X-ray photoelectron spectroscopy (XPS) analysis.
摘要:
本文报道了PVA薄膜中金纳米复合材料各种含量的系统光致发光研究。PVA膜中金含量的变化为0.2、0.5、1.0和1.5wt。%.所有样品在两个选择的波长下激发;那些是在400nm和532nm。与在400nm处显示发射的纯PVA膜相比,在400nm处激发Au-PVA纳米复合膜时,在430-500nm的区域观察到光致发光。然而,在532nm的Au-PVA纳米复合材料上,在560-650nm处观察到发射,具有长尾直到700nm,这与在该区域中不显示任何发射峰的纯PVA膜不同。这表明在430-500nm区域之间的发射是由于PVA与金纳米颗粒的配位,因为PVA在400nm处具有发射。然而,在560-650nm之间的发射峰完全是由于金纳米颗粒。该峰还显示出较小的红移,这通常是随着PVA膜中的含量增加而增加的纳米颗粒尺寸。通过XPS分析进一步支持的XRD分析证明了金纳米颗粒的形成。