基于金纳米阵列表面等离子体驱动的光催化特性

Photocatalytic properties of gold nanoarrays driven by surface plasmon

金属纳米结构中传导电子的集体振荡所产生的表面等离子体不仅可以在时间和空间上重新分布电磁场,还可以重新分布被激发的载流子.由表面等离子体引起的各种效应,包括增强的电磁场、局部加热、激发的电子和激发的空穴,可以驱动化学反应等.本文基于阳极氧化铝模板制备出排列规则的金纳米阵列催化基底,当特定波长的激发光作用于该基底时其表面将会产生大量排列规则的局域表面等离子体增强区域.借助表面增强拉曼光谱技术具有指纹普的优势,实时监测以对氨基硫酚作为探针分子在局域表面等离子体的驱动下发生光催化反应生成4,4′-二巯基偶氮苯.此后,原位引入硼氢化钠在相同的实验条件下,可以将生成物4,4′-二巯基偶氮苯在等离子体的驱动下再一次发生逆向化学反应生成对氨基硫酚分子.该项研究工作将在微纳尺度下实现分子图形的绘制和擦除,基于该技术进行信息加密、读取和擦写等领域具有潜在的应用价值.

The surface plasmons produced by the collective oscillation of conduction electrons in metal nanostructures can redistribute not only the electromagnetic field spatiotemporally,but also the excited carriers.Various effects caused by surface plasmons,including enhanced electromagnetic fields,local heating,excited electrons and excited holes,can drive chemical reactions.In this work,the regularly-arranged Au nanoarray catalytic substrate is prepared based on an anodic aluminum oxide template.When the excitation light of a specific wavelength irradiates on the substrate,a large number of regularly-arranged local surface plasmon enhancement regions will be generated on its surface.By taking advantage of surface enhanced Raman spectroscopy,the 4,4′-dimercaptoazobenzene is synthesized by the photocatalytic reaction of p-aminothiophenol as a probe driven by local surface plasmon.After that,the sodium borohydride is introduced in situ.Under the same experimental conditions,the product 4,4′-dimercaptoazobenzene is driven by plasma to produce p-aminothiophenol again.This research work will achieve the drawing and erasing of molecular graphics on a micro scale and a nano scale,as well as information encryption,reading and erasing,which has a strong application value.