Plasmon-Driven Enhancement in CO2 Photoreduction: Mechanistic Elucidation and Materials Design Strategies

Abstract

Under the background of global carbon neutrality, photocatalytic reduction of carbon dioxide (CO2) technology has become a research hotspot due to its sustainability and energy conversion potential. However, traditional photocatalysts are limited by problems such as low light absorption efficiency, high carrier recombination rate and difficult reaction path regulation. In contrast, plasmon materials provide a new idea to break through these bottlenecks through the local surface plasmon resonance (LSPR) effect, which significantly enhances both the utilization rate of light energy and the reaction kinetic efficiency through localized electromagnetic fields enhancement, hot electron injection and photothermal synergy. Initially, precious metal materials became the core of research due to their strong LSPR response, but their high cost and insufficient stability restricted large-scale application. To this end, non-precious metal systems have achieved precious metal-like properties through defect engineering (such as oxygen vacancies, nitrogen vacancies) and structural design (such as ultrathin nanosheets, heterojunctions), making progress in wide-spectrum response and long-term stability. Moreover, the co-design of composite materials and heterojunctions further optimizes the charge separation efficiency and the adsorption capacity of intermediates, promoting the multi-electron reduction path and the selectivity improvement of C2+ products. In-situ characterization techniques and reaction kinetics studies have revealed the dynamic mechanism of the photocatalytic process, providing theoretical support for material optimization. In the future, it is necessary to overcome the challenges of insufficient stability of non-precious metal materials, low utilization efficiency of near-infrared light and industrial scale-up. Advancements in multi-field coupling reactors, biomimetic structure optimization and high-throughput material screening are expected to play key roles in facilitating the transformation of CO2 photoreduction technology from the laboratory to practical large-scale implementations.