Li Jieqiong, Wei Shiyu, Dong Ying, Zhang Yongya, Wang Li
Henan Engineering Center of New Energy Battery Materials, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, China.
Henan Key Laboratory of Protection and Safety Energy Storage of Light Metal Materials, Henan University, Kaifeng 475004, China.
Molecules. 2024 Aug 29;29(17):4105. doi: 10.3390/molecules29174105.
The construction of anatase/rutile heterojunctions in TiO is an effective way of improving the CO photoreduction activity. Yet, the origin of the superior photocatalytic performance is still unclear. To solve this issue, the band edges between anatase and rutile phases were theoretically determined based on the three-phase atomic model of (112)/II/(101), and simultaneously the CO reduction processes were meticulously investigated. Our calculations show that photogenerated holes can move readily from anatase to rutile via the thin intermediated II phase, while photoelectrons flowing in the opposite direction may be impeded due to the electron trapping sites at the II phase. However, the large potential drop across the anatase/rutile interface and the strong built-in electric field can provide an effective driving force for photoelectrons' migration to anatase. In addition, the II phase can better enhance the solar light utilization of (112)/(100), including a wide light response range and an intensive optical absorption coefficient. Meanwhile, the mixed-phase TiO possesses negligible hydrogenation energy (CO to COOH*) and lower rate-limiting energy (HCOOH* to HCO*), which greatly facilitate CHOH generation. The efficient charge separation, strengthened light absorption, and facile CO reduction successfully demonstrate that the anatase/rutile mixed-phase TiO is an efficient photocatalyst utilized for CO conversion.
在TiO中构建锐钛矿/金红石异质结是提高CO光还原活性的有效方法。然而，这种优异光催化性能的起源仍不清楚。为了解决这个问题，基于(112)/II/(101)的三相原子模型从理论上确定了锐钛矿相和金红石相之间的能带边缘，同时对CO还原过程进行了细致研究。我们的计算表明，光生空穴可以通过薄的中间II相从锐钛矿轻松移动到金红石，而由于II相处的电子俘获位点，沿相反方向流动的光电子可能会受到阻碍。然而，锐钛矿/金红石界面上的大电势降和强内建电场可以为光电子迁移到锐钛矿提供有效的驱动力。此外，II相可以更好地提高(112)/(100)的太阳光利用率，包括宽的光响应范围和强烈的光吸收系数。同时，混合相TiO具有可忽略不计的氢化能(CO到COOH*)和较低的限速能(HCOOH到HCO)，这极大地促进了CHOH的生成量增加。高效的电荷分离、增强的光吸收以及 facile CO还原成功证明了锐钛矿/金红石混合相TiO是用于CO转化的高效光催化剂。 （注：原文中“facile”可能有误，推测可能是“ facile”，这里按“容易的、便捷的”意思翻译为“ facile”，但不确定是否准确，你可根据实际情况调整。）
