Tuning redox potentials of CO2 reduction catalysts for carbon photofixation by Si nanowires


Si nanowires (SiNWs) are shown to absorb visible light to reduce Ni catalysts into Ni0 compounds, enabling alkyne carboxylation reactions with CO2 as a carbon feedstock. The reduced Ni catalysts are effective in CO2 fixation through a 4-octyne carboxylation reaction. The reduction potentials of the Ni catalysts can be tuned from -1.35 to -0.51 V (vs. saturated calomel electrode) by altering the binding ligands. The results shed light on the nature of charge transfer from SiNWs to the catalyst for this new class of photocatalytic reactions. By controlling the CO2 reduction potential of the catalysts with carefully ligand designs, it will bring more opportunities and options to realize the highly selective, effective and sustainable CO2 reduction in the future.


硅纳米线在吸收光之后还原催化剂镍离子, 从而引发以二氧化碳为碳原料的炔烃羧基化反应. 镍催化剂的还原态产物在这 一固碳反应中能够非常高效地将4-辛炔羧酸化. 配位体的给电子基团和吸电子基团的能力不同, 将会影响催化剂的氧化还原电 位. 还原 电位由于构成镍催化剂的配位体不同, 控制在−1.35到−0.51 V(相对于甘汞电极电位)之间. 这种新的光催化反应本质上是 利用了硅纳 米线在光照时产生的光电子从半导体界面转移到催化剂的现象, 通过改变催化剂的配位体实现控制催化剂的还原电位. 此方法 为实现 设计可持续性高效的二氧化碳还原反应提供了更多的选择.


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Corresponding authors

Correspondence to Rui Liu or Dunwei Wang.

Additional information

Rui Liu is a material processing & integration research engineer in the Joint Center for Artificial Photosynthesis at California Institute of Technology. She got her PhD degree from Boston College in 2013, MSc and BSc degrees from Polymer Science Department, Fudan University in 2007 and 2004. Her research focuses on high efficient, large scale and sustainable water splitting and carbon dioxide reduction photoelectrochemistry.

Dunwei Wang is an associate professor of chemistry at Boston College. He received his BSc and PhD degrees, both in chemistry, from the University of Science and Technology of China (2000) and Stanford University (2005), respectively. Researches of his group are on harvesting and storage of solar energy.

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Liu, R., Stephani, C., Tan, K.L. et al. Tuning redox potentials of CO2 reduction catalysts for carbon photofixation by Si nanowires. Sci. China Mater. 58, 515–520 (2015). https://doi.org/10.1007/s40843-015-0068-8

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