Cobalt Plasmonic Superstructures Enable Almost 100% Broadband Photon Efficient CO2 Photocatalysis
Kai Feng1?, Shenghua Wang1?, Dake Zhang1?, Lu Wang2, Yingying Yu1, Kun Feng1, Zhao Li2, Zhijie Zhu1, Chaoran Li1, Mujin Cai1, Zhiyi Wu1, Ning Kong1, Binhang Yan3, Jun Zhong1*, Xiaohong Zhang1*, Geoffrey A. Ozin2*, and Le He1*
1Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University-Western University Centre for Synchrotron Radiation Research, Soochow University, 199 Ren’ai Road, Suzhou, Jiangsu 215123, People’s Republic of China
2Materials Chemistry and Nanochemistry Research Group, Solar Fuels Cluster, Departments of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
3Department of Chemical Engineering, Tsinghua University, Beijing 100084, People’s Republic of China
The efficiency of heterogeneous photocatalysis for converting solar to chemical energy is low on a per photon basis mainly because of the difficulty of capturing and utilizing light across the entire solar spectral wavelength range. This challenge is addressed herein with a plasmonic superstructure, fashioned as an array of nanoscale needles comprising cobalt nanocrystals assembled within a sheath of porous silica grown on a fluorine tin oxide substrate. This plasmonic superstructure can strongly absorb sunlight through different mechanisms including enhanced plasmonic excitation by the hybridization of Co nanoparticles in close proximity, as well as inter- and intra-band transitions. With nearly 100% sunlight harvesting ability, it drives the photothermal hydrogenation of carbon dioxide with a 20-fold rate increase from the silica-supported cobalt catalyst. The present work bridges the gap between strong light-absorbing plasmonic superstructures with photothermal CO2 catalysis toward the complete utilization of the solar energy.