| 慈成刚,周霞,覃再鑫,黄茜茜,陈银会,付雪燕.化学通报,2022,85(1):132-138. |
| 多钨酸纳米团簇光劈裂水产氢机理的TDDFT研究 |
| Mechanistic Insight into the Photo-splitting of Water to Dihydrogen Catalyzed by Polytungstic Acid Nanoclusters: A TDDFT Study |
| 投稿时间：2021-05-24 修订日期：2021-06-27 |
| DOI： |
| 中文关键词: 多钨酸纳米团簇 水劈裂 H2产生 反应机理 含时密度泛函理论 |
| 英文关键词:Polytungstic acid nanoclusters, Photo-splitting of water, H2-generation, Mechanism, TDDFT |
| 基金项目:贵州省科技厅项目(黔科合基础[2020]1Y050)、黔南民族师范学院项目(qnsyk201601)和大学生创新创业项目(20195201785)资助 |
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| 中文摘要: |
| 本文采用密度泛函理论(DFT)和含时密度泛函理论(TDDFT)方法对多钨酸纳米团簇[XW12O40]n- (X = P, Si, Ge, B)的紫外-可见光谱和电子跃迁机理进行了模拟，并对其光催化劈裂水产氢气机理进行了计算。计算结果显示实验观测到紫外-可见吸收峰均来自配体到金属的电荷转移跃迁(LMCT)，即电子由氧原子p轨道跃迁到金属钨的d轨道。因单电子还原(OER)中间体激发后总能量超过实验阈值(λ > 300 nm)，催化剂通过能量弛豫回到基态成为有利途径。接下来的双电子还原(TER)和氢气产生均存在热力学有利的放热反应，且质子化在这些过程中扮演了重要角色。多钨酸纳米团簇在整个催化循环中扮演了光敏剂、催化剂、电子给体和受体的角色。 |
| 英文摘要: |
| The ultraviolet-visible spectra (UV-Vis), electronic transition mechanism, photo-splitting mechanism of water to obtain H2 by polytungstic acid nanoclusters, [XW12O40]n- (X = P, Si, Ge, and B) has been investigated using DFT and TDDFT calculations. The calculation results show that experimental observed UV-Vis absorbed peaks are generated by ligand-to-metal charge transfer transition (LMCT) of the catalysts, that is, the excitation from the p-type orbitals of O-atom to d-type orbitals of W-atom. Due to the total energy of one-electron reduction (OER) process exceeds the energy threshold (λ > 300 nm), the catalysts return to the ground state by energy relaxation become the favorable pathway. The following two-electron reduction (TER) and H2 generation both have thermodynamically favorable exothermic reactions, and the protonation plays an important role. The catalysts act as photosensitizer, catalyst, electron reservoir and donner. |
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