Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry the Chinese Academy of Sciences, Beijing 100190 (P.R. China), Fax: (+86) 10-8254-3580; These authors contributed equally to this work.
ChemSusChem. 2015 Feb;8(4):642-9. doi: 10.1002/cssc.201402885. Epub 2014 Dec 3.
A visible-light-induced hydrogen evolution system based on a CdSe quantum dots (QDs)-TiO2 -Ni(OH)2 ternary assembly has been constructed under an ambient environment, and a bifunctional molecular linker, mercaptopropionic acid, is used to facilitate the interaction between CdSe QDs and TiO2 . This hydrogen evolution system works effectively in a basic aqueous solution (pH 11.0) to achieve a hydrogen evolution rate of 10.1 mmol g(-1) h(-1) for the assembly and a turnover frequency of 5140 h(-1) with respect to CdSe QDs (10 h); the latter is comparable with the highest value reported for QD systems in an acidic environment. X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and control experiments demonstrate that Ni(OH)2 is an efficient hydrogen evolution catalyst. In addition, inductively coupled plasma optical emission spectroscopy and the emission decay of the assembly combined with the hydrogen evolution experiments show that TiO2 functions mainly as the electron mediator; the vectorial electron transfer from CdSe QDs to TiO2 and then from TiO2 to Ni(OH)2 enhances the efficiency for hydrogen evolution. The assembly comprises light antenna CdSe QDs, electron mediator TiO2 , and catalytic Ni(OH)2 , which mimics the strategy of photosynthesis exploited in nature and takes us a step further towards artificial photosynthesis.
基于 CdSe 量子点 (QDs)-TiO2-Ni(OH)2 三元组装体的可见光诱导制氢体系在环境条件下构建，双功能分子连接体巯基丙酸促进了 CdSe QDs 与 TiO2 之间的相互作用。该制氢体系在碱性水溶液（pH 11.0）中有效工作，组装体的制氢速率为 10.1 mmol g(-1) h(-1)，对于 CdSe QDs 的周转率为 5140 h(-1)（10 h）；后者与酸性环境中 QD 体系的最高值相当。X 射线光电子能谱、X 射线吸收光谱和控制实验表明 Ni(OH)2 是一种高效的制氢催化剂。此外，电感耦合等离子体发射光谱和组装体的发射衰减以及制氢实验表明 TiO2 主要作为电子介体；从 CdSe QDs 到 TiO2 的向量电子转移，然后从 TiO2 到 Ni(OH)2 的电子转移增强了制氢效率。该组装体包含光天线 CdSe QDs、电子介体 TiO2 和催化 Ni(OH)2，模拟了自然界中光合作用所采用的策略，使我们朝着人工光合作用又迈进了一步。
