Prolonged Hot Electron Dynamics in Plasmonic-Metal/Semiconductor Heterostructures with Implications for Solar Photocatalysis
Prolonged Hot Electron Dynamics in Plasmonic-Metal/Semiconductor Heterostructures with Implications for Solar Photocatalysis
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DOI：
10.1002/anie.201404259
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发表时间：
2014-07-21
影响因子：
16.6
通讯作者：
Wei, Wei David
中科院分区：
文献类型：
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作者：
DuChene, Joseph S.;Sweeny, Brendan C.;Wei, Wei David
理想的太阳能转化为燃料的光催化剂必须有效地收集阳光，才能产生化学反应所需的大量长寿命电荷载流子。在这里，我们展示了用等离子体纳米粒子增强传统光电化学电池的优点，以满足这些令人望而生畏的光催化要求。用电化学方法研究了溶液中可见光(波长515 nm)照射下Au/TiO2光催化异质结中等离子体介导的电子转移机理。值得注意的是，我们发现这些转移电子的激发态寿命比通过紫外光激发直接在二氧化钛中产生的电子长两个数量级。这些长寿命电子进一步使可见光驱动的氢气从水中演化出来，预示着太阳能转换的新的光催化范例。
Ideal solar-to-fuel photocatalysts must effectively harvest sunlight to generate significant quantities of long-lived charge carriers necessary for chemical reactions. Here we demonstrate the merits of augmenting traditional photoelectrochemical cells with plasmonic nanoparticles to satisfy these daunting photocatalytic requirements. Electrochemical techniques were employed to elucidate the mechanics of plasmon-mediated electron transfer within Au/TiO2 heterostructures under visible-light (lambda > 515 nm) irradiation in solution. Significantly, we discovered that these transferred electrons displayed excited-state lifetimes two orders of magnitude longer than those of electrons photogenerated directly within TiO2 via UV excitation. These long-lived electrons further enable visible-light-driven H-2 evolution from water, heralding a new photocatalytic paradigm for solar energy conversion.