Near Unity Quantum Yield of Light-Driven Redox Mediator Reduction and Efficient H2 Generation Using Colloidal Nanorod Heterostructures

详细信息    查看全文

• 作者：Haiming Zhu ; Nianhui Song ; Hongjin Lv ; Craig L. Hill ; Tianquan Lian
• 刊名：The Journal of the American Chemical Society
• 出版年：2012
• 出版时间：July 18, 2012
• 年：2012
• 卷：134
• 期：28
• 页码：11701-11708
• 全文大小：458K
• 年卷期：v.134,no.28(July 18, 2012)
• ISSN：1520-5126

文摘

The advancement of direct solar-to-fuel conversion technologies requires the development of efficient catalysts as well as efficient materials and novel approaches for light harvesting and charge separation. We report a novel system for unprecedentedly efficient (with near-unity quantum yield) light-driven reduction of methylviologen (MV²⁺), a common redox mediator, using colloidal quasi-type II CdSe/CdS dot-in-rod nanorods as a light absorber and charge separator and mercaptopropionic acid as a sacrificial electron donor. In the presence of Pt nanoparticles, this system can efficiently convert sunlight into H₂, providing a versatile redox mediator-based approach for solar-to-fuel conversion. Compared to related CdSe seed and CdSe/CdS core/shell quantum dots and CdS nanorods, the quantum yields are significantly higher in the CdSe/CdS dot-in-rod structures. Comparison of charge separation, recombination and hole filling rates in these complexes showed that the dot-in-rod structure enables ultrafast electron transfer to methylviologen, fast hole removal by sacrificial electron donor and slow charge recombination, leading to the high quantum yield for MV²⁺ photoreduction. Our finding demonstrates that by controlling the composition, size and shape of quantum-confined nanoheterostructures, the electron and hole wave functions can be tailored to produce efficient light harvesting and charge separation materials.