Experimental Identification of Ultrafast Reverse Hole Transfer at the Interface of the Photoexcited Methanol/Graphitic Carbon Nitride System
Experimental Identification of Ultrafast Reverse Hole Transfer at the Interface of the Photoexcited Methanol/Graphitic Carbon Nitride System
复制标题
光激发甲醇/石墨氮化碳体系界面超快反向空穴传输的实验鉴定
DOI：
10.1002/anie.201713102
复制
发表时间：
2018-05-04
影响因子：
16.6
通讯作者：
Luo, Yi
中科院分区：
文献类型：
--
作者：
Chen, Zongwei;Zhang, Qun;Luo, Yi
在一个原型系统中，空穴清除甲醇分子化学吸附在石墨碳氮化物（g-C3 N4）基板的光激发空穴动力学的实验审查。利用飞秒时间分辨瞬态吸收（fs-TA）光谱技术进行了一系列对比和对照实验。人们发现了难以捉摸的反向空穴传输（RHT）过程，该过程发生在几百微微秒的时间尺度上。界面化学吸附的甲氧基（而不是甲醇）作为主要物种负责空穴清除的关键作用被确认通过使用质子化的g-C3 N4作为基板的对照实验。通过不同的带间光激发方案揭示了热空穴转移效应。RHT速率是决定不同空穴清除剂清除空穴能力的关键因素。
An experimental scrutiny of the photoexcited hole dynamics in a prototypical system is presented in which hole-scavenging methanol molecules are chemisorbed on a graphitic carbon nitride (g-C3N4) substrate. A set of comparison and control experiments by means of femtosecond time-resolved transient absorption (fs-TA) spectroscopy were conducted. The elusive reverse hole transfer (RHT) process was identified, which occurs on a timescale of a few hundred picoseconds. The critical role of interfacially chemisorbed methoxy (instead of methanol) as the dominant species responsible for hole scavenging was confirmed by a control experiment using protonated g-C3N4 as the substrate. A hot-hole transfer effect was revealed by implementing different interband photoexcitation scenarios. The RHT rate is the key factor governing the hole-scavenging ability of different hole scavengers.