Photolysis versus Photothermolysis of N2O on a Semiconductor Surface Revealed by Nonadiabatic Molecular Dynamics,Journal of the American Chemical Society

当前位置： X-MOL 学术 › J. Am. Chem. Soc. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Photolysis versus Photothermolysis of N2O on a Semiconductor Surface Revealed by Nonadiabatic Molecular Dynamics
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2022-12-21 , DOI: 10.1021/jacs.2c10643
Cheng Cheng ₁ , Oleg V Prezhdo ₂ , Run Long ₁ , Wei-Hai Fang ₁

Affiliation

Identifying photolysis and photothermolysis during a photochemical reaction has remained challenging because of the highly non-equilibrium and ultrafast nature of the processes. Using state-of-the-art ab initio adiabatic and nonadiabatic molecular dynamics, we investigate N₂O photodissociation on the reduced rutile TiO₂(110) surface and establish its detailed mechanism. The photodecomposition is initiated by electron injection, leading to the formation of a N₂O^– ion-radical, and activation of the N₂O bending and symmetric stretching vibrations. Photothermolysis governs the N₂O dissociation when N₂O^– is short-lived. The dissociation is activated by a combination of the anionic excited state evolution and local heating. A thermal fluctuation drives the molecular acceptor level below the TiO₂ band edge, stabilizes the N₂O^– anion radical, and causes dissociation on a 1 ps timescale. As the N₂O^– resonance lifetime increases, photolysis becomes dominant since evolution in the anionic excited state activates the bending and symmetric stretching of N₂O, inducing the dissociation. The photodecomposition occurs more easily when N₂O is bonded to TiO₂ through the O rather than N atom. We demonstrate further that a thermal dissociation of N₂O can be realized by a rational choice of metal dopants, which enhance p–d orbital hybridization, facilitate electron transfer, and break N₂O spontaneously. By investigating the charge dynamics and lifetime, we provide a fundamental atomistic understanding of the competition and synergy between the photocatalytic and photothermocatalytic dissociation of N₂O and demonstrate how N₂O reduction can be controlled by light irradiation, adsorption configuration, and dopants, enabling the design of high-performance transition-metal oxide catalysts.

中文翻译：

非绝热分子动力学揭示的半导体表面上 N2O 的光解与光热解

由于过程的高度非平衡和超快性质，在光化学反应过程中识别光解和光热解仍然具有挑战性。使用最先进的从头算绝热和非绝热分子动力学，我们研究了还原金红石 TiO ₂ (110) 表面上的 N _{2 O 光解离并建立了其详细机制。}光分解由电子注入引发，导致形成 N ₂ O ^-离子自由基，并激活 N ₂ O 弯曲和对称伸缩振动。当 N ₂ O ^–时，光热分解控制 N _{2 O 解离}是短暂的。解离由阴离子激发态演变和局部加热的组合激活。热波动驱动分子受体水平低于 TiO ₂带边缘，稳定 N ₂ O ^-阴离子自由基，并导致 1 ps 时间尺度的解离。随着 N ₂ O ^-共振寿命的增加，光解成为主导，因为阴离子激发态的演化激活了 N ₂ O 的弯曲和对称拉伸，从而诱导解离。当N _{2 O与TiO}₂键合时更容易发生光分解通过 O 而不是 N 原子。我们进一步证明，通过合理选择金属掺杂剂可以实现N _{2 O 的热解离，从而增强}p – d轨道杂化，促进电子转移，并自发地分解 N ₂ O。_{通过研究电荷动力学和寿命，我们提供了对 N 2} O的光催化和光热催化解离之间的竞争和协同作用的基本原子理解，并展示了如何通过光照射、吸附配置和掺杂剂控制N ₂ O 还原，从而实现高性能过渡金属氧化物催化剂的设计。

更新日期：2022-12-21

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南