How to Evaluate and Manipulate Charge Transfer and Photocatalytic Response at Hybrid Nanocarbon–Metal Oxide Interfaces
How to Evaluate and Manipulate Charge Transfer and Photocatalytic Response at Hybrid Nanocarbon–Metal Oxide Interfaces
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DOI：
10.1002/adfm.201704730
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发表时间：
2018-04
影响因子：
19
通讯作者：
N. Kemnade;P. Gebhardt;Greta M. Haselmann;A. Cherevan;G. Wilde;D. Eder
中科院分区：
文献类型：
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作者：
N. Kemnade;P. Gebhardt;Greta M. Haselmann;A. Cherevan;G. Wilde;D. Eder
纳米碳-金属氧化物杂化物是许多尖端环境和能源应用中最有前途的功能材料之一，其中有效的电荷分离和提取是成功的关键。一旦人们学会了如何控制和调整界面处的电荷/能量传输过程，就可以实现下一级别的混合结构。然而，人们对纳米碳杂化物中这些界面动力学的性质和程度知之甚少。这里设计了一个模型，其中混合组分（ZnO、TiO2）和碳纳米管之间的超薄介电层（Al2O3、ZrO2）允许在至少 50 nm 的异常长距离上评估和调整界面电荷转移。令人惊讶的是，转移效率与势垒层厚度线性相关，表明电子通过势垒层的传导构成了限速步骤。还证明，电荷转移效率可以通过中间层的类型及其结晶度来调节，从而控制杂化物在光催化制氢中的性能。据信，该模型系统将有助于理解和破译纳米碳杂化物中界面电荷和能量转移的基本原理，旨在进一步推进这些杂化结构的广泛能源应用。
Nanocarbon–metal oxide hybrids are among the most promising functional materials in many cutting‐edge environmental and energy applications where efficient charge separation and extraction are keys to success. The next level of hybrid structures will be achieved once one learns how to control and tune charge/energy transfer processes at the interfaces. However, little is yet known about the nature and extent of these interfacial dynamics in nanocarbon hybrids. Here a model is designed in which ultrathin dielectric layers (Al2O3, ZrO2) between the hybrid's components (ZnO, TiO2) and carbon nanotubes allow for evaluating and tuning of interfacial charge transfer over an unusually long distance of at least 50 nm. Surprisingly, the transfer efficiency correlates linearly with the barrier layer thickness, indicating that electron conduction through the barrier layer constitutes the rate‐limiting step. It is also demonstrated that the charge transfer efficiency can be tuned by the type of interlayer and its degree of crystallinity, thus controlling the hybrid's performance in the photocatalytic production of hydrogen. It is believed that this model system will help to understand and decipher the fundamentals regarding interfacial charge and energy transfer in nanocarbon hybrids with the aim to further advance these hybrid structures for a wide range of energy applications.