Shining a light on carbon neutrality: A comprehensive review of plasmon-assisted electrocatalytic CO₂ reduction
image: Scheme diagram of LSPR excitation (The interaction between light illumination and metal nanostructures causes the oscillation of the electron clouds)
Credit: Jing Xue, Zhenlin Chen, Yuchao Zhang & Jincai Zhao.
With global carbon dioxide (CO₂) emissions reaching approximately 36.8 billion tons in 2023, the climate crisis demands urgent and innovative solutions. Converting CO₂ into high value-added fuels and chemical products through the CO₂ reduction reaction (CO₂RR) is a highly promising approach to storing renewable energy and achieving carbon neutrality. However, activating the highly stable C=O double bonds requires overcoming substantial energy barriers, and the multi-electron transfer process inherently suffers from sluggish kinetics.
A new review article published in ENGINEERING Energy (formerly Frontiers in Energy) provides a comprehensive analysis of how localized surface plasmonic resonance (LSPR) can overcome these fundamental challenges. Authored by researchers from the Institute of Chemistry at the Chinese Academy of Sciences and the University of Chinese Academy of Sciences, the review details how plasmonic effects can dramatically enhance the activity and product selectivity of electrocatalytic CO₂RR.
When plasmonic metals—such as gold (Au), silver (Ag), and copper (Cu)—are illuminated, they exhibit LSPR, an effect that generates energetic "hot carriers" (electrons and holes) and localized photothermal heating. The review meticulously distinguishes between these hot carrier and photothermal effects, highlighting how hot electrons can directly transfer to adsorbed CO₂ molecules, effectively lowering the activation energy barriers for chemical bond cleavage.
The authors systematically summarize recent developments in plasmonic catalysts, categorizing them into single plasmonic metals, bimetallic heterostructures, and plasmonic metal/semiconductor heterostructures. Single plasmonic metals like Cu, which possess a moderate CO binding energy, are particularly appealing for forming complex multi-carbon (C₂₊) products like ethylene and ethanol. Furthermore, creating heterostructures—such as pairing plasmonic metals with catalytically active metals or semiconductors—can generate internal electric fields that suppress the rapid recombination of hot carriers, significantly accelerating the catalytic reaction and prolonging carrier lifetime.
The review concludes that while plasmon-assisted electrocatalytic CO₂RR shows tremendous potential for sustainable energy development, the field still faces crucial hurdles before industrialization. The researchers emphasize the urgent need for in situ characterization techniques to accurately monitor catalyst surface reconstruction, morphological transformations, and intermediate formations in real-time. Looking forward, the design of low-cost catalysts capable of full solar spectrum absorption, coupled with the ability to operate efficiently in environmentally friendly neutral electrolytes, will be essential for advancing the commercial viability of CO₂ reduction technologies.
JOURNAL ENGINEERING Energy (formerly Frontiers in Energy)
Article Link https://link.springer.com/article/10.1007/s11708-024-0950-8
Cite this article XUE J, CHEN Z, ZHANG Y, ZHAO J. A review on plasmonic enhancement of activity and selectivity in electrocatalytic CO₂ reduction. Frontiers in Energy, 2024, 18(4): 399-417. https://doi.org/10.1007/s11708-024-0950-8