在温和温度下对TiO2多态物进行有效的兴奋剂,以对可见光有反应的进化
Yaping Chen1, Shangyi Ma2, Yongqiang Yang1
1School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China; Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.
Journal of colloid and interface science
|March 15, 2024
概括
使用尿素对二氧化 (TiO2) 进行温和的氧化兴奋剂增强了光催化演变. 这种方法避免了缺陷,改善了电子传输,使得anatase和rutile TiO2的可见光反应更好.
科学领域:
- 材料科学 材料科学 材料科学
- 光催化作用的光催化
- 表面化学 表面化学
背景情况:
- 二氧化 (TiO2) 是一个关键的光催化剂,但它的效率受到其宽带间隔的限制,限制了可见光的吸收.
- 开发可见光驱动光催化方法对于进化等应用至关重要.
- 兴奋剂是一种常见的策略,用于缩小TiO2的带隙,增强可见光活性.
研究的目的:
- 开发一种使用尿素衍生的气态物种对TiO2进行温和温度的兴奋剂方法.
- 为了研究酸 (HOCN) 在TiO2.2的兴奋剂中的作用.
- 为了比较光催化进化表现的温和温度化TiO2与高温化样品.
主要方法:
- 使用尿素对解酶和鲁TiO2进行温和的化.
- 密度功能理论 (DFT) 模拟以了解兴奋剂机制.
- 光催化进化速度测量.
- 稳态和瞬态表面光伏的特征.
主要成果:
- 在可见光下,对解酶和鲁基TiO2的温和兴奋剂显著提高了可见光下的演化速率.
- DFT模拟确定了酸 (HOCN) 作为在温和温度下有效的兴奋剂的活性物种.
- 尽管可见光吸收率增加,但高温兴奋剂导致了对电子传输有害的缺陷.
- 温和温度的兴奋剂使带曲平坦而不会形成Ti3+缺陷,改善可见光诱导的电子传输.
结论:
- 与高温方法相比,温和温度兴奋剂是一种优越的策略,用于增强可见光光催化在TiO2中的演化.
- 在兴奋剂期间控制缺陷形成对于优化光催化剂性能至关重要.
- 这种方法为弥合宽带间隙金属氧化物中光吸收和光活性之间的差距提供了一条途径.
相关概念视频
Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
Photoluminescence: Applications
Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...


