What Makes the Photocatalytic CO2 Reduction on N-Doped Ta2O5 Efficient: Insights from Nonadiabatic Molecular Dynamics
What Makes the Photocatalytic CO2 Reduction on N-Doped Ta2O5 Efficient: Insights from Nonadiabatic Molecular Dynamics
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DOI：
10.1021/jacs.5b07454
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发表时间：
2015-09-09
影响因子：
15
通讯作者：
Prezhdo, Oleg V.
中科院分区：
文献类型：
--
作者：
Akimov, Alexey V.;Asahi, Ryoji;Prezhdo, Oleg V.
最近的实验研究表明，组装在N掺杂Ta 2 O3表面的Ru催化剂的光催化CO2还原强烈依赖于Ru配合物与基底连接的锚基团的性质。本文报道了电子中性Ru（di-X-bpy）（CO）（2）Cl-2配合物（X = COOH，PO_3H_2）在N-Ta_2 O_5衬底上的电子转移动力学的原子学分析.非绝热分子动力学模拟表明，电子转移是更快的复合物与COOH锚比复合物与PO 3 H2基团，由于较大的非绝热耦合。然而，量子相干性在很小程度上抵消了这种效应。COOH锚促进了转移与显着更高的频率模式比PO 3 H2，由于更轻的原子（C与P）和更强的键（双与单）。受体状态离域到COOH上，但不是PO 3 H2，进一步有利于COOH系统中的电子转移。同时，COOH锚易于分解，与PO 3 H2相反，使得前者在某些情况下显示较小的周转数。这些理论预测与最近的实验结果是一致的，合理的电子转移的机制。我们强调的作用，锚稳定性，非绝热耦合，和量子相干在确定人工光催化系统的整体效率。
Recent experimental studies demonstrated that photocatalytic CO2 reduction by Ru catalysts assembled on N-doped Ta2O3 surface is strongly dependent on the nature of the anchor group with which the Ru complexes are attached to the substrate. We report a comprehensive atomistic analysis of electron transfer dynamics in electroneutral Ru(di-X-bpy) (CO)(2)Cl-2 complexes with X = COOH and PO3H2 attached to the N-Ta2O5 substrate. Nonadiabatic molecular dynamics simulations indicate that the electron transfer is faster in complexes with COOH anchors than in complexes with PO3H2 groups, due to larger nonadiabatic coupling. Quantum coherence counteracts this effect, however, to a small extent. The COOH anchor promotes the transfer with significantly higher frequency modes than PO3H2, due to both lighter atoms (C vs P) and stronger bonds (double vs single). The acceptor state delocalizes onto COOH, but not PO3H2, further favoring electron transfer in the COOH system. At the same time, the COOH anchor is prone to decomposition, in contrast to PO3H2, making the former show smaller turnover numbers in some cases. These theoretical predictions are consistent with recent experimental results, legitimating the proposed mechanism of the electron transfer. We emphasize the role of anchor stability, nonadiabatic coupling, and quantum coherence in determining the overall efficiency of artificial photocatalytic systems.