Changing interfaces: Photoluminescent ZnO nanoparticle powders in different aqueous environments
Changing interfaces: Photoluminescent ZnO nanoparticle powders in different aqueous environments
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DOI：
10.1016/j.susc.2016.02.019
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发表时间：
2016-10-01
期刊：
影响因子：
1.9
通讯作者：
Diwald, Oliver
中科院分区：
文献类型：
--
作者：
Kocsis, Krisztina;Niedermaier, Matthias;Diwald, Oliver
我们将气相生长的ZnO纳米颗粒粉末转化为ZnO纳米颗粒的水分散体，并研究了相关的微观结构和界面性质的变化对它们的光谱性质的影响。利用光致发光（PL）光谱，我们探测了近表面区域的氧化合物O-i（2-），并跟踪了它们在固体真空到固液界面的受控转换过程中在hv（EM）= 2.1eV处的特定PL发射响应。虽然通过气相的氧吸附确实影响PL发射带的强度，但在固液界面上与ZnO纳米颗粒接触的O-2不影响。此外，我们发现，在HV（Em）= 3.2 eV的近带边发射功能的增益相对强度与PL发射功能在可见光regions.Searching潜在的PL指标，是特定的颗粒溶解的早期阶段，我们解决了ZnO纳米粒子的水分散体的甲酸吸附的效果。在相关的光谱特征的情况下，我们能够始终跟踪ZnO纳米颗粒溶解和伴随形成的溶剂化甲酸锌物种的PL和FT-IR光谱，动态光散射，和zeta电位测量。为了对不同连续相中的纳米颗粒性质进行更一致和更可靠的评估，我们讨论了用固液界面取代固-气时出现的表征挑战和潜在陷阱。(C)2016作者由爱思唯尔公司出版
We transformed vapor phase grown ZnO nanoparticle powders into aqueous ZnO nanoparticle dispersions and studied the impact of associated microstructure and interface property changes on their spectroscopic properties. With photoluminescence (PL) spectroscopy, we probed oxygen interstitials O-i(2-) in the near surface region and tracked their specific PL emission response at hv(EM) = 2.1 eV during the controlled conversion of the solid vacuum into the solid-liquid interface. While oxygen adsorption via the gas phase does affect the intensity of the PL emission bands, the O-2 contact with ZnO nanoparticles across the solid-liquid interface does not. Moreover, we found that the near band edge emission feature at hv(Em) = 3.2 eV gains relative intensity with regard to the PL emission features in the visible light region.Searching for potential PL indicators that are specific to early stages of particle dissolution, we addressed for aqueous ZnO nanoparticle dispersions the effect of formic acid adsorption. In the absence of related spectroscopic features, we were able to consistently track ZnO nanoparticle dissolution and the concomitant formation of solvated Zinc formate species by means of PL and FT-IR spectroscopy, dynamic light scattering, and zeta potential measurements. For a more consistent and robust assessment of nanoparticle properties in different continuous phases, we discuss characterization challenges and potential pitfalls that arise upon replacing the solid-gas with the solid-liquid interface. (C) 2016 The Authors. Published by Elsevier B.V.