3D-Array of Au-TiO2 Yolk-Shell as Plasmonic Photocatalyst Boosting Multi-Scattering with Enhanced Hydrogen Evolution
3D-Array of Au-TiO2 Yolk-Shell as Plasmonic Photocatalyst Boosting Multi-Scattering with Enhanced Hydrogen Evolution
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DOI：
10.1021/acsami.6b12940
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发表时间：
2016-11-23
影响因子：
9.5
通讯作者：
Majima, Tetsuro
中科院分区：
文献类型：
--
作者：
Shi, Xiaowei;Lou, Zaizhu;Majima, Tetsuro
如今，如何将太阳能有效地转化为其他能源，例如化学能，是一个重要的课题。在目前的工作中，制备了单包封在TiO2空心纳米球（Au-TiO2）中的金纳米球（AuNS）和Au-TiO2的三维组装阵列（3D阵列），以仔细探索分别在模拟太阳光和可见光照射下多重散射对H-2生成光催化活性的影响。通过SiO2保护方法均匀合成内腔直径为176 nm的Au-TiO2，然后将其用作构建3D阵列的构件。 3D阵列表现出比Au-TiO2更高的光催化H-2生成活性（可见光照射下是3.5倍，太阳光照射下是1.4倍）。通过单粒子等离子体光致发光测量和有限差分时域（FDTD）计算模拟来阐明光催化的详细机制。这表明AuNS在可见光照射下产生的热电子在光催化过程中发挥着重要作用。 3D 阵列的较高活性是由于 Au-TiO2 和 TiO2 壳内部的反射之间的多重散射而延长了光路长度。因此，AuNS有更多的机会吸收光，并且预计通过从AuNS到TiO2壳层的电子转移会产生更多的热电子，从而导致H-2生成量的增加。这一结果为我们构建高效光利用结构提供了新的视角。
Nowadays, how to convert solar energy efficiently to other energies, such as chemical energy, is an important subject. In the present work, gold nanosphere (AuNS) monoencapsulated in TiO2 hollow nanosphere (Au-TiO2) and three-dimensional assembled array of Au-TiO2 (3D-array) were fabricated to carefully explore the multiscattering effect on the photocatalytic activity of H-2 generation under simulated solar light and visible light irradiation, respectively. Au-TiO2 with the inner cavity diameter of 176 nm was uniformly synthesized via SiO2 protection method and then was used as building blocks for construction of 3D-array. The 3D-array exhibited a much higher photocatalytic activity of H-2 generation (3.5 folds under visible light irradiation, 1.4 folds under solar light irradiation) than Au-TiO2. Single-particle plasmonic photoluminescence measurement and computational simulation of finite difference time domain (FDTD) were performed to elucidate the detailed mechanisms of photocatalysis. It was suggested that the hot electrons generated by AuNS under visible light irradiation play a significant role during the photocatalysis process. The higher activity of 3D-array is due to the elongation of light path length because of the multiscattering in-between Au-TiO2 and the reflection inside of the TiO2 shell. Therefore, the AuNS has more opportunity to absorb light and more hot electrons are expected to be generated through the electron transfer from AuNS to TiO2 shell, leading to an increment in the H-2 generation. This result gives us a new perspective of constructing structures for efficient light utilization.