Charge Separation and Transport Dynamics in One-Dimensional Colloidal Nanostructures for Solar Energy Conversion
olar energy conversion, particularly solar-driven chemical fuel formation, has been intensely studied in the past decade as a potential approach for renewable energy generation. Efficient solar-to-fuel conversion requires artificial photosynthetic systems with strong light absorption, long-lived charge separation and efficient catalysis. Colloidal quantum confined nanoheterostructures have emerged as promising materials for this application because of the ability to tailor their properties through size, shape and composition. In particular, colloidal one-dimensional (1D) semiconductor nanorods (NRs) offer the opportunity to simultaneously maintain quantum confinement in radial dimensions for tunable light absorptions and bulk like carrier transport in the axial direction for long-distance charge separations. In addition, the versatile chemistry of colloidal NRs enables the formation of semiconductor heterojunctions to separate photogenerated electron-hole pairs and deposition of metallic domains to accept charges and catalyze redox reactions. In this talk, I report our recent research progress on colloidal NR heterostructures and their applications for solar energy conversion, emphasizing on mechanistic insights into the working principle of these systems. I will introduce their electronic structures and dynamics of carrier transport and interfacial transfer obtained from time-resolved spectroscopic studies. I will also discuss how these carrier dynamics are controlled by their structures and provide key mechanistic understanding on their light driven H2 generation performances.