Powering a CO2 Reduction Catalyst with Visible Light through Multiple Sub-picosecond Electron Transfers from a Quantum Dot
Powering a CO2 Reduction Catalyst with Visible Light through Multiple Sub-picosecond Electron Transfers from a Quantum Dot
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DOI：
10.1021/jacs.7b03134
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发表时间：
2017-07-05
影响因子：
15
通讯作者：
Weiss, Emily A.
中科院分区：
文献类型：
--
作者：
Lian, Shichen;Kodaimati, Mohamad S.;Weiss, Emily A.
将CO2还原为CO的分子催化剂的光敏化是可储存太阳能燃料的可持续途径。敏化过程的关键是氧化还原当量从敏化剂到催化剂的高效转移;在具有分子敏化剂的系统中，这种转移通常是缓慢的，因为它是由敏化剂和催化剂之间的扩散限制碰撞门控的。本文描述了一种meso-四苯基卟啉氯化铁（FeTPP）催化剂的光敏化，通过胶体，无重金属的CuInS 2/ZnS量子点（QD）使用450 rim光将CO2还原为CO。的量子点系统的敏化效率（每吸收单位的光子能量的周转数）是一个因素的18大于一个类似的系统与fac-tris（2-苯基吡啶）铱敏化剂。这种高效率源于QD和FeTPP之间的超快电子转移，这是通过形成QD/FeTPP复合物实现的。光谱学揭示了主要负责前两个敏化步骤（（FeTPP）-T-III ->（FeTPP）-T-II和（FeTPP）-T-II ->（FeTPP）-T-I）的电子转移过程都发生在
Photosensitization of molecular catalysts to reduce CO2 to CO is a sustainable route to storable solar fuels. Crucial to the sensitization process is highly efficient transfer of redox equivalents from sensitizer to catalyst; in systems with molecular sensitizers, this transfer is often slow because it is gated by diffusion-limited collisions between sensitizer and catalyst. This article describes the photosensitization of a meso-tetraphenylporphyrin iron(III) chloride (FeTPP) catalyst by colloidal, heavy metal-free CuInS2/ZnS quantum dots (QDs) to reduce CO2 to CO using 450 rim light. The sensitization efficiency (turnover number per absorbed unit of photon energy) of the QD system is a factor of 18 greater than that of an analogous system with a fac-tris(2-phenylpyridine)iridium sensitizer. This high efficiency originates in ultrafast electron transfer between the QD and FeTPP, enabled by formation of QD/FeTPP complexes. Optical spectroscopy reveals that the electron-transfer processes primarily responsible for the first two sensitization steps ((FeTPP)-T-III -> (FeTPP)-T-II, and (FeTPP)-T-II -> (FeTPP)-T-I) both occur in