Photocatalytic reactions with particulate photocatalysts are regarded as the simplest and most cost-effective means of artificial photosynthesis due to its facile material fabrication and large-scale application. Driven by light irradiation, a photocatalytic reaction is developed to produce high-energy-density products. Via this reaction, variable and un-continuous solar energy can be converted to chemical energy.
Our research focuses on photocatalytic water splitting for H2 generation and O2 reduction for H2O2 generation, since their reactants (H2O and O2) are abundant and these reactions are more thermodynamically favorable than other reactions like CO2 reduction. At the same time, both of them are clean-energy carriers and can be applied in fuel cells to generate electric power.
Project 1 Development of wide-spectrum-responsive photocatalysts
Oxides, such as SrTiO3, have been extensively studied as photocatalysts; however, their solar energy conversion efficiencies are limited by poor light absorption. In contrast, metal-doped oxides (e.g., Rh-doped SrTiO3), oxynitrides (e.g., LaTiO2N), and oxysulfides (e.g., Gd2Ti2O5S2) exhibit intense absorption in the visible-light spectrum, extending up to ~ 650 nm. Despite this enhanced light absorption, these materials still face challenges in achieving high conversion efficiencies for the absorbed light. The activation of these novel materials is a crucial step in advancing the field of artificial photosynthesis.
Reference: ACS Catalysis, 6, (2016), 7188-7196; Journal of Catalysis, 399, (2021), 230-236; Sustain. Energy Fuels, 6, (2022), 2067-2074; Nature Communications, 13, (2022), 1034; Nano Research, 15, (2022), 10090-10109; Angew. Chem.Int. Ed.2023,62, e20231293
Project 2 Photochemistry over photocatalytic reactions
Photocatalytic reactions involves interrelated charge separation within the bulk of the photocatalyst and charge transfer across the photocatalyst/(cocatalyst)/water interface. Despite their important roles in photocatalytic activities, these processes remain inadequately understood. This project is designed to scrutinize these intricate processes through (photo-)electrochemical and spectroscopic analyses. The ultimate goal is to offer fresh insights for material development in the realm of photocatalysis. (The spectroscopic analysis is supported by Yamakata Lab, Okayama University.)
Reference: Sustain. Energy Fuels, 3, (2019), 850-864; Energy Environ. Sci., 13, (2020),162-173; ACS Catalysis, 12, (2022), 14727-14734; Nature Communications, 13, (2022), 7783; J. Phys. Chem. C, 127, 7, (2023), 3904–3909; ACS Energy Letters, 7, (2022), 432-452
Project 3 Development of scalable photocatalyst panel
Previous research has advanced the development of powdered suspension-type photocatalysts for artificial photosynthesis. However, for the future practical implementation of this technology, it is indispensable to develop scalable and cost-effective fixed-bed catalytic reactors (e.g., photocatalyst panel). In collaboration with Chu Lab, Zhejiang University, China, we are developing portable and low-cost photocatalyst panels with efficient doctor-blade technologies.
Reference: Manuscript Under Review
