Primary photocatalytic water reduction and oxidation at an anatase TiO2 and Pt-TiO2 nanocrystalline electrode revealed by quantitative transient absorption studies
Primary photocatalytic water reduction and oxidation at an anatase TiO2 and Pt-TiO2 nanocrystalline electrode revealed by quantitative transient absorption studies
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DOI：
10.1016/j.apcatb.2021.120226
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发表时间：
2021-04
影响因子：
22.1
通讯作者：
Hanming Liu;Maning Liu;R. Nakamura;Y. Tachibana
中科院分区：
文献类型：
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作者：
Hanming Liu;Maning Liu;R. Nakamura;Y. Tachibana
利用一系列瞬时吸收光谱仪对锐钛矿型纳米二氧化钛薄膜与水的电子和空穴转移动力学进行了定量研究。对于水还原反应，导带和俘获电子都以两个不同的单指数分量衰减，时间尺度相差6∼7个数量级。较快的反应发生在8-16 ns，而较慢的组分的寿命为0.1∼1.4 S。铂纳米粒子沉积在二氧化钛表面使较慢的单一指数反应转变为一个伸展的指数反应，加速的半衰期为2-7 ms，表明这种较慢的反应受到二氧化钛内部电子捕获-脱陷运动的限制。水氧化反应在100 ns到200 ms之间呈多指数关系发生，半衰期为10μS；二氧化钛表面的铂催化水氧化反应，发生在25 ns，半衰期为8μS。
Quantitative assessments of electron and hole transfer dynamics with water on anatase nanocrystalline TiO2films were conducted by employing a series of transient absorption spectrometers. For water reduction reactions, both conduction band and trapped electrons decay with two different single exponential components with the difference in time scale of 6∼7 orders of magnitudes. The faster reaction occurs in 8–16 ns, while the slower component shows a lifetime of 0.1∼1.4 s. Pt nanoparticle deposition on the TiO2surface switches the slower single exponential reaction to a stretched exponential with an accelerated half lifetime of 2–7 ms, indicating that this slower reaction is limited by the electron trapping-detrapping movements inside the TiO2. Water oxidation reactions occur multi-exponentially from 100 ns to 200 ms with a half lifetime of 10 μs. Pt on the TiO2surface catalyses water oxidation, occurring from 25 ns with a half lifetime of 8 μs.