The preparation of semiconductor nanoparticles by PLA in water and the their evaluation as functional materials

PLA在水中制备半导体纳米粒子及其功能材料评价

• 批准号: 17560592
• 负责人: TANAKA Katsumi
• 金额: $ 2.24万
• 依托单位: The University of Electro-Communications
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560592/
• 关键词: Titania nanoparticles; Pulsed Laser Ablation; PLA in Water; ICP-Mass; Visible Light Response; Environmental Cleaning; Quantum Size Effect; Thin Film; パルスレーザーアプレーション; 微粒子半導体; 酸化チタン; シリコン微粒子; 光触媒; 半導体微粒子; 可視光応答触媒; Titania nanoparticles; Pulsed Laser Ablation; PLA in Water; ICP-Mass; Visible Light Response; Environmental Cleaning; Quantum Size Effect; Thin Film; パルスレーザーアプレーション; 微粒子半導体; 酸化チタン; シリコン微粒子; 光触媒; 半導体微粒子; 可視光応答触媒

The amount of titanium formed by TiO2 single crystal PLA in water was measured by ICP-mass spectrometry. The PLA yield was evaluated as a function of laser fluence, water thickness, pH and temperature in solution, and acid kind. The yield was mainly controlled by the former two factors and was shown by two equations. The size and behavior of titania particles on the substrate were studied with STM. The size of the particles as small as 4nm was detected and they easily moved on the substrate surface by biased voltage between tip and nano-particles. The bandgap of the thin films was measured to be 3.87 to 4.13eV with diffused reflectance spectroscopy. Such clear bandgap enlargement due to quantum-size effect is quite unique only on these nano-particles. Such blue shift is disadvantage for the photo-catalytic reaction on TiO2. However, the thin films were photo-active to methylene blue degradation not only with ultraviolet but also with >400nm visible light. The fact was interpreted by the impurity levels formed in between the enlarged bandgap such as nitrogen involved by PTA in water. Probably high concentration of impurity in nanoparticles play significant role on producing much holes active for photo-oxidation with visible light.

TiO2单晶PLA在水中形成的钛的量通过ICP质量光谱法测量。评估PLA的产量是激光通量，水厚度，pH和溶液中的温度以及酸性的函数。产量主要由前两个因素控制，并由两个方程式显示。用STM研究了底物上钛颗粒的大小和行为。检测到小至4nm的颗粒的大小，并通过尖端和纳米粒子之间的偏置电压轻松移动在底物表面。薄膜的带隙被测量为3.87至4.13EV，具有扩散的反射率光谱。由于量子尺寸效应引起的这种清晰的带隙扩大仅在这些纳米颗粒上是非常独特的。这种蓝移是TiO2上光催化反应的缺点。但是，薄膜不仅用紫外线，而且具有> 400nm的可见光光活性到亚甲基蓝色降解。事实是由在水中涉及的氮中含量的氮中形成的杂质水平来解释的。纳米颗粒中可能高浓度的杂质在产生可见光的光氧化的大量孔中起着重要作用。