SusChEM: Visible Light-Driven Reduction of Carbon Dioxide using Heavy Metal-Free Colloidal Quantum Dots as Sensitizers

SusChEM：使用不含重金属的胶体量子点作为敏化剂进行可见光驱动的二氧化碳还原

• 批准号: 1664184
• 负责人: Emily Weiss
• 金额: $ 40.86万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-15 至 2020-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1664184&HistoricalAwards=false
• 关键词: SusChEM; Visible; Light; Driven; Reduction

The use of sunlight to convert carbon dioxide (CO2) to various small molecules that can be used as fuels is a sustainable way to exploit abundant solar energy for use both during day and night. The chemical reactions involved in this conversion are complicated and multi-step, and typically involve the transfer of electrons from one molecule to another. A "photocatalyst" is a species that lowers the energy barriers for, and thereby facilitates, such complex reactions by using light energy to drive chemical reactions. With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Emily Weiss of Northwestern University is conducting fundamental studies to identify and optimize photocatalyts for CO2 conversion in catalyst designs that comprise molecules adsorbed to the surfaces of semiconductor nanoparticles made of non-toxic, earth abundant materials. Her studies involve both chemical analysis of these hybrid inorganic-organic complexes and laser spectroscopy to monitor their behaviors on ultrafast timescales after excitation with light energy. Dr. Weiss is actively involved in the mentoring of undergraduate researchers on this project, in the development of a new curriculum for General Chemistry at Northwestern University to increase retention of women and minority students under-represented in STEM fields, and in programs like the Gateway Science Workshop, which offers structured study sessions for students in STEM courses, particularly those students with weaker high school preparation. With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Emily Weiss of Northwestern University is identifying and optimizing the most important thermodynamic and kinetic parameters in the performance of ternary heavy metal-free colloidal CuInX2 (X = S, Se) quantum dots (QDs) as soluble, multi-site, colloidal sensitizers for photocatalysis of the reduction of CO2 in solution. This work illuminates the mechanisms by which specific and unique properties of a colloidal QD sensitizer enhance the performance of a molecular catalyst with known specificity for CO2 reduction, by addressing several fundamental challenges associated with this task, namely: (i) synthesis and surface functionalization of a QD sensitizer with enough reducing power to donate multiple electrons to the co-catalyst; (ii) control of the local concentration of hydrogen ions; (iii) fast hole extraction from the sensitizer to inhibit recombination and photo-oxidative degradation; and (iv) maximal electronic coupling between the sensitizer and the co-catalyst to provide pathways for fast electron delivery. One and two dimensional nuclear magnetic resonance (NMR) spectroscopy, electron microscopy, electrochemical measurements and steady-state and time resolved optical measurements allow for quantitative characterization of the binding affinity for the QD-catalyst pair, the proton (H+) concentration on the QD surface, the degree of adsorption of the catalytic substrates and intermediates, the rate constants for elementary electron and hole transfer steps, and the efficacy of hole scavenging. These techniques complement the gas and liquid chromatography, NMR, and infrared spectroscopy characterization of product distributions and reaction rates. In addition to the societal impact of finding new pathways to produce carbon- and hydrogen-based fuels from sunlight and CO2 using a non-toxic, earth-abundant colloidal catalyst, this work has broad impact in that undergraduates will be involved both in the proposed research and in ongoing curriculum reform of General Chemistry by Dr. Weiss, in order to increase retention of women and under-represented minority students in STEM fields at Northwestern University.

使用阳光将二氧化碳（CO2）转换为可以用作燃料的各种小分子是一种可持续的方法，可利用大量的太阳能在白天和黑夜使用。这种转化涉及的化学反应是复杂且多步的，通常涉及电子从一个分子转移到另一个分子。 “光催化剂”是一种降低能量壁垒的物种，从而促进了这种复杂的反应，通过使用轻能驱动化学反应。借助化学分部的化学催化计划的资助，西北大学的艾米莉·韦斯（Emily Weiss）正在进行基础研究，以识别和优化催化剂设计中的二氧化碳转化的光催化剂，这些催化剂conversion型构成了构成分子的含量，这些分子吸附到了由无毒的，地球含量，地球纳米颗粒的表面上，这些分子是由无毒的，地球上丰富的材料。 她的研究涉及对这些杂交无机有机复合物和激光光谱的化学分析，以监测其在轻度能量激发后对超快时间尺度上的行为。魏斯博士积极参与本科研究人员对该项目的指导，以开发西北大学的一项新课程，以增加在STEM领域的女性和少数族裔学生的保留，以及在Gateway Science工作室等课程中，该课程在STEM科学工作室等课程中为STEM的学生提供了弱小的学生的结构性学习，尤其是那些弱小的学生。 通过化学分部化学催化计划的资助，西北大学的艾米莉·魏斯（Emily Weiss）博士正在确定和优化最重要的热力学和动力学参数，以执行三元重金属无胶体cuinx2（x = s = s，s，s，s，s，qds）的量子（qds）量子，胶体，胶体，胶体敏感性的量子量。这项工作阐明了胶体QD敏化剂的特定和独特特性通过解决与此任务相关的几个基本挑战，即具有已知的二氧化​​碳挑战，从而增强了分子催化剂的性能，即：（i）具有足够降低QD敏化功率的多种促进剂来供多个coat sopate Electerals so-cot coat soc-cat coat coats coat coat coat coat coat coat coat coat soc-cot coat coat coat coat coat coat coat coat coat coat coat coat coat coat coAt coat coat coat coAt; （ii）控制氢离子的局部浓度； （iii）从敏化剂中提取快速孔以抑制重组和光氧化降解； （iv）敏化器和共催化剂之间的最大电子耦合，以提供快速电子传递的途径。 One and two dimensional nuclear magnetic resonance (NMR) spectroscopy, electron microscopy, electrochemical measurements and steady-state and time resolved optical measurements allow for quantitative characterization of the binding affinity for the QD-catalyst pair, the proton (H+) concentration on the QD surface, the degree of adsorption of the catalytic substrates and intermediates, the rate constants for elementary electron and孔转移步骤，孔清除的功效。这些技术补充了产品分布和反应速率的气相和液相色谱，NMR和红外光谱表征。除了找到新的途径以使用无毒的，地球丰富的胶体催化剂从阳光和二氧化碳中生产碳和氢的燃料的社会影响外，这项工作还具有广泛的影响，因为本科生将涉及拟议的研究，以及在韦斯（Weiss）进行的一般性化学课程中，为了使妇女的持续阶层和卑鄙的妇女居住。

项目成果

Oxidation of a Molecule by the Biexcitonic State of a CdS Quantum Dot

• DOI: 10.1021/acs.jpcc.9b00210
• 发表时间: 2019-02
• 期刊: The Journal of Physical Chemistry C
• 作者: Shichen Lian;Joseph A. Christensen;Mohamad S. Kodaimati;Cameron R. Rogers;M. Wasielewski;E. Weiss

Quantum Dot‐Catalyzed Photoreductive Removal of Sulfonyl‐Based Protecting Groups

量子点催化光还原去除磺酰基保护基团

• DOI: 10.1002/ange.202005074
• 发表时间: 2020
• 期刊: Angewandte Chemie
• 作者: Perez, Kaitlyn A.;Rogers, Cameron R.;Weiss, Emily A.
• 通讯作者: Weiss, Emily A.

Viewpoint: Challenges in Colloidal Photocatalysis and Some Strategies for Addressing Them

• DOI: 10.1021/acs.inorgchem.7b03182
• 发表时间: 2018-04-02
• 期刊: INORGANIC CHEMISTRY
• 影响因子: 4.6
• 作者: Kodaimati, Mohamad S.;McClelland, Kevin P.;Weiss, Emily A.
• 通讯作者: Weiss, Emily A.

Systematic control of the rate of singlet fission within 6,13-diphenylpentacene aggregates with PbS quantum dot templates

使用 PbS 量子点模板系统控制 6,13-​​二苯基并五苯聚集体中的单线态裂变速率

• DOI: 10.1039/c8fd00157j
• 发表时间: 2019
• 期刊: Faraday Discussions
• 影响因子: 3.4
• 作者: Wang, Chen;Kodaimati, Mohamad S.;Lian, Shichen;Weiss, Emily A.
• 通讯作者: Weiss, Emily A.