在聚乙烯酒精薄膜中对WO3基于光色的动态研究
Suzuko Yamazaki1, Koki Isoyama1
1Department of Chemistry, College of Science, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8512, Japan.
Langmuir : the ACS journal of surfaces and colloids
|July 11, 2023
概括
氧化 (WO3) 的光色在薄膜和合溶液之间有所不同. 水在775纳米处稳定散体间隔电荷转移 (IVCT),而表面IVCT发生在640和984纳米处.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 摄影化学的使用.
背景情况:
- 氧化 (WO3) 呈现光色,这是由于W6+和W5+离子之间的间隔电荷转移 (IVCT),导致蓝色.
- 之前的研究报告了WO3光色素的不同吸收光谱,需要更深入地了解底层机制.
- 在不同的矩阵 (合溶液与薄膜) 中研究WO3纳米粒子可以阐明影响光色行为的因素.
研究的目的:
- 为了研究和比较氧化物 (WO3) 纳米颗粒在合溶液中的光色行为与透明薄膜.
- 阐明批量和表面现象对观察到的吸收光谱和色彩动力学的特定贡献.
- 了解水和乙烯基醇 (EG) 在稳定WO3膜中的光诱导电荷转移状态中的作用.
主要方法:
- 使用聚乙烯醇,WO3纳米颗粒和乙烯基醇 (EG) 制备透明的WO3纳米颗粒薄膜.
- 对WO3合溶液和薄膜进行紫外线照射,然后进行吸收光谱,以分析光谱变化.
- 吸收光谱的解卷,色化速率 (r0) 的动态研究,拉曼光谱和电子自旋共振 (ESR) 光谱.
主要成果:
- 体WO3溶液在紫外线照射下显示在777nm左右的单个吸收峰值.
- WO3膜呈现出明显的光谱变化,从770nm的峰值演变为654nm和1003nm的两个峰值.
- 两种系统的吸收光谱被分解成五个峰值,动力学研究显示出大量 (775 nm) 和表面 (640,984 nm) IVCT 对水和EG含量的不同依赖.
结论:
- 在WO3中775nm的吸收峰值归因于由水稳定的大批量IVCT.
- 在640和984nm的吸收峰值被分配给WO3表面发生的IVCT.
- 光生成的电子迁移到WO3膜中的终端WO部分,从而产生可观测的ESR信号.
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