|
|||||
|
|
CO2 Overall Splitting by a Bifunctional Metal‐Free Electrocatalyst |
|
| Authors: | Muhammad Arsalan Ghausi Dr Jiafang Xie Prof Qiaohong Li Xueyuan Wang Rui Yang Prof Maoxiang Wu Prof Yaobing Wang Prof Liming Dai |
| Institution: | 1. CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Nanomaterials, State Key Laboratory of Structural Chemistry, Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, P. R. China;2. University of Chinese Academy of Sciences, Beijing, China;3. Department of Macromolecular Science and Engineering, Case School of Engineering, Case Western Reserve University, Cleveland, OH, USA;4. UNSW-CWRU International Joint Laboratory, School of Chemical Engineering, University of New South Wales, Sydney, NSW, Australia |
| Abstract: | Photo/electrochemical CO2 splitting is impeded by the low cost‐effective catalysts for key reactions: CO2 reduction (CDRR) and water oxidation. A porous silicon and nitrogen co‐doped carbon (SiNC) nanomaterial by a facile pyrolyzation was developed as a metal‐free bifunctional electrocatalyst. CO2‐to‐CO and oxygen evolution (OER) partial current density under neutral conditions were enhanced by two orders of magnitude in the Tafel regime on SiNC relative to single‐doped comparisons beyond their specific area gap. The photovoltaic‐driven CO2 splitting device with SiNC electrodes imitating photosynthesis yielded an overall solar‐to‐chemical efficiency of advanced 12.5 % (by multiplying energy efficiency of CO2 splitting cell and photovoltaic device) at only 650 mV overpotential. Mechanism studies suggested the elastic electron structure of ?Si(O)?C?N? unit in SiNC as the highly active site for CDRR and OER simultaneously by lowering the free energy of CDRR and OER intermediates adsorption. |
| Keywords: | bifunctional systems CO2 reduction electrocatalysis metal-free electrodes nanomaterials |