Rational Design of Dot‐on‐Rod Nano‐Heterostructure for Photocatalytic CO 2 Reduction: Pivotal Role of Hole Transfer and Utilization

Autor: Hong-Wei Song, Fengtao Fan, Xu-Bing Li, Yu-Ji Gao, Zhi-Kun Xin, Jiaqing Zhao, Li-Zhu Wu, Chen-Ho Tung, Yuying Gao, An-Dong Xia
Rok vydání: 2021
Předmět:
Zdroj: Advanced Materials. 34:2106662
ISSN: 1521-4095
0935-9648
Popis: Inspired by green plants, artificial photosynthesis has become one of the most attractive approaches toward carbon dioxide (CO2 ) valorization. Semiconductor quantum dots (QDs) or dot-in-rod (DIR) nano-heterostructures have gained substantial research interest in multielectron photoredox reactions. However, fast electron-hole recombination or sluggish hole transfer and utilization remains unsatisfactory for their potential applications. Here, the first application of a well-designed ZnSe/CdS dot-on-rods (DORs) nano-heterostructure for efficient and selective CO2 photoreduction with H2 O as an electron donor is presented. In-depth spectroscopic studies reveal that surface-anchored ZnSe QDs not only assist ultrafast (≈2 ps) electron and hole separation, but also promote interfacial hole transfer participating in oxidative half-reactions. Surface photovoltage (SPV) spectroscopy provides a direct image of spatially separated electrons in CdS and holes in ZnSe. Therefore, ZnSe/CdS DORs photocatalyze CO2 to CO with a rate of ≈11.3 µmol g-1 h-1 and ≥85% selectivity, much higher than that of ZnSe/CdS DIRs or pristine CdS nanorods under identical conditions. Obviously, favored energy-level alignment and unique morphology balance the utilization of electrons and holes in this nano-heterostructure, thus enhancing the performance of artificial photosynthetic solar-to-chemical conversion.
Databáze: OpenAIRE
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