飞秒激光诱导金纳米球壳形貌变化

Femtosecond Laser-Induced Shape Change from Gold Nanoshell to Nanotube

摘要:

采用800 nm的飞秒（10-15 s，fs，下同）激光对湿化学法制备的金纳米球壳水溶胶进行辐照，研究辐照后金纳米球壳的形貌变化。结果表明，原来直径为20~50 nm的准球壳形纳米金粒子辐照后变为管状结构，其直径约为10 nm，长度为100~200 nm。辐照后其吸收光谱在约800 nm处的吸收峰消失，在约450 nm处出现了新的吸收峰。这种飞秒激光辐照下形貌变化的原因为：在飞秒激光辐照下产生了静电场，在电场力的作用下，相互靠近的金纳米球壳彼此链接，并沿着电场方向伸展，形成了管状结构。

Abstract:

Colloidal gold nanoshells prepared by wet chemical method were irradiated using 800 nm femtosecond laser and their shape change was investigated. Results show that the gold nanoparticles of quasi-sphere-shells with 20~50 nm diameter changed to tube structure of 100~200 nm length and 10 nm diameter after femtosecond laser exposure. In the adsorption spectra, the absorption peak of the gold nanoshell at about 800 nm disappeared and a new absorption peak appeared at about 450 nm. The shape change can be attributed to the electrostatic field from the femtosecond laser exposure. With the force of the electrostatic field, nearby gold nanoshells linked each other, and extended along the electrostatic filed direction to form tube structure.