Photoacoustic spectra of Au quantum dots adsorbed on nanostructured TiO2 electrodes together with the photoelectrochemical current characteristics
Photoacoustic spectra of Au quantum dots adsorbed on nanostructured TiO2 electrodes together with the photoelectrochemical current characteristics
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DOI：
10.1063/1.3074500
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发表时间：
2009-02
影响因子：
3.2
通讯作者：
T. Toyoda;Sae Tsugawa;Q. Shen
中科院分区：
文献类型：
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作者：
T. Toyoda;Sae Tsugawa;Q. Shen
利用光声光谱技术研究了Au量子点的光吸收特性。Au量子点的特征频带被观察到在约2.4 eV的电极组成的15 nm的TiO 2纳米粒子和在约2.3 eV的那些组成的37 nm的，这对应于在可见光区的特征表面等离子体共振带。在这两种情况下，PA信号强度在特征频带周围的电极厚度依赖性表现出饱和的趋势。尽管Au量子点的制备条件相同，但不同粒径的TiO2纳米粒子制备的电极的PA信号强度的饱和特性存在很大差异。用37 nm TiO2纳米颗粒制成的电极的饱和时间比用15 nm颗粒制成的电极的饱和时间短，这表明QD渗透到用37 nm纳米颗粒制成的电极中小于用15 nm纳米颗粒制成的电极中，尽管观察到的多孔面积高。此外，具有15 nm纳米颗粒的电极的峰周围的PA信号强度大于具有37 nm的电极的PA信号强度，这表明由于较大纳米颗粒的较低表面活化能，较小纳米颗粒的吸附速率较高。利用表面等离子体共振技术观察到了Au量子点的特征吸收带，但没有光电化学电流响应.利用光声光谱技术研究了Au量子点的光吸收特性. Au量子点的特征频带被观察到在约2.4 eV的电极组成的15 nm的TiO 2纳米粒子和在约2.3 eV的那些组成的37 nm的，这对应于在可见光区的特征表面等离子体共振带。在这两种情况下，PA信号强度在特征频带周围的电极厚度依赖性表现出饱和的趋势。尽管Au量子点的制备条件相同，但不同粒径的TiO2纳米粒子制备的电极的PA信号强度的饱和特性存在很大差异。用37 nm TiO2纳米颗粒制成的电极的饱和时间比用15 nm颗粒制成的电极的饱和时间短，表明量子点渗透到用37 nm纳米颗粒制成的电极中。
The optical absorption of Au quantum dots (QDs) was studied by applying the photoacoustic (PA) spectroscopic technique, which is useful for optically opaque samples. The characteristic bands of Au QDs were observed at around 2.4 eV for electrodes consisting of 15 nm TiO2 nanoparticles and at around 2.3 eV for those consisting of 37 nm ones, which correspond to the characteristic surface plasmon resonance bands in the visible region. The electrode thickness dependence of the PA signal intensity around the characteristic band showed a tendency toward saturation in both cases. There was a great difference in the saturation characteristics of the PA signal intensity between the electrodes made with different sized TiO2 nanoparticles, even though the preparation conditions for the Au QDs were the same. The saturation time for electrodes made with 37 nm TiO2 nanoparticles was shorter than those made with 15 nm particles, indicating that the penetration of the QDs into the electrodes made with 37 nm nanoparticles was less than those made with 15 nm nanoparticles, although the porous area observed was high. Also, the PA signal intensity around the peak of electrodes with 15 nm nanoparticles is larger than that with 37 nm ones, indicating a higher adsorption rate for the smaller nanoparticles due to the lower surface activation energy of larger nanoparticles. There was no photoelectrochemical current response although the characteristic optical absorption bands of the Au QDs were observed by surface plasmon resonance.The optical absorption of Au quantum dots (QDs) was studied by applying the photoacoustic (PA) spectroscopic technique, which is useful for optically opaque samples. The characteristic bands of Au QDs were observed at around 2.4 eV for electrodes consisting of 15 nm TiO2 nanoparticles and at around 2.3 eV for those consisting of 37 nm ones, which correspond to the characteristic surface plasmon resonance bands in the visible region. The electrode thickness dependence of the PA signal intensity around the characteristic band showed a tendency toward saturation in both cases. There was a great difference in the saturation characteristics of the PA signal intensity between the electrodes made with different sized TiO2 nanoparticles, even though the preparation conditions for the Au QDs were the same. The saturation time for electrodes made with 37 nm TiO2 nanoparticles was shorter than those made with 15 nm particles, indicating that the penetration of the QDs into the electrodes made with 37 nm nanoparticle...