Professor Jung kyu Kim’s research group (School of Chemical Engineering, Sungkyunkwan University), in collaboration with Professor Ji-hee Kim’s group and Professor Seok joon Kwon’s group, developed a novel plasmonic nanostructure that amplifies the local electromagnetic field (E-field) on a metal oxide-based photoelectrode. This advancement significantly improves photoelectrochemical (PEC) water oxidation performance and enables the solar-to-chemical energy conversion by oxidizing glycerol, a major byproduct of biodiesel production, into value-added chemicals.

Water electrolysis technology for green hydrogen production, as a zero-carbon and eco-friendly alternative fuel, faces critical limitations in practical application due to the sluggish kinetics of the oxidative reaction at the anode. Therefore, the development of efficient oxidation electrodes is essential for improving water electrolysis performance. To address this, PEC systems that utilize solar energy have been introduced to improve oxidation performance at photoanode. However, transition metal-based photoelectrode materials commonly used in PEC systems still suffer from poor electrical conductivity and poor surface oxidation activity, hindering to achieve efficient oxidation performance at the anode.

To resolve the aforementioned drawbacks, the research team was inspired by the solar-driven nature of PEC systems and introduced a plasmonic nanostructure activated by solar energy into the photoanode. This approach achieved a synergistic effect, enhancing the oxidative reaction at the photoanode while realizing efficient solar-to-chemical energy conversion.

Utilizing the close relationship between the photoelectrode performance and the generation of internal E-field, the research team designed a novel plasmonic structure that amplifies the E-field through intra-cluster and inter-cluster coupling effects. In particular, an ultrathin insulating layer (~5 nm) was introduced on plasmonic nanostructures to facilitate the energy trasnfer mechanism from amplified E-field to photoanode. This approach enhanced charge transport efficiency, maximized surface photovoltage, and significantly improved surface charge transfer efficiency of photoanode. As a result, the developed c-Au/BVO photoanode exhibited enhanced solar water oxidation performance and enabled the highly active PEC glycerol oxidation reaction, producing high-value-added chemical products.

The research team demonstrated improved photo-generated charge carrier dynamics with the introduction of plasmonic nanostructure through transient absorption spectroscopy, Kelvin probe force microscopy, and in-situ attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, thereby revealed the underlying mechanism of improved oxidative reactions.

This research provides a promising solar-to-chemical energy conversion strategy that enhances the oxidation reaction in water electrolysis for practical application and creates value from waste resources in the biodiesel industry, thereby contributing to the realization of a sustainable carbon-neutral society.

This research achievement was accepted for publication in 'Applied Catalysis B: Environment and Energy' (DOI: https://doi.org/10.1016/j.apcatb.2025.125600) on June 15, 2025.

※ Title: Plasmon Induced Field Amplification for Enhancing Photoelectrochemical Oxidative Valorization
※ Journal: Applied Catalysis B: Environment and Energy
※ Link: https://doi.org/10.1016/j.apcatb.2025.125600

A high-performance solar-to-chemical energy conversion technology using plasmonic structures that amplify electromagnetic fields

Development of an oxide semiconductor electrode incorporating plasmonic structures that amplify sunlight-induced electromagnetic fields

The plasmonic structures enhance the light-induced electromagnetic fields, improving photoelectrochemical energy conversion performance

(Co-corresponding Author): Professor Seokjoon Kwon, Department of Chemical Engineering, Sungkyunkwan University

(First Author): Seunghoon Noh, Integrated Master’s-PhD Program, Department of Chemical Engineering, Sungkyunkwan University