Jeonbuk National University (JBNU) researchers have developed a photocatalyst modification technique that reduces dependence on precious metals by using electron beam irradiation, attracting attention in the academic community.

A collaborative research team led by Professor Seung-Hwa Yu of the Department of Quantum System Engineering, JBNU, and Professor Kyung-Hwan Jin of the Department of Physics fabricated a heterojunction-structured photocatalyst by combining the two-dimensional nanomaterial MXene—hailed as a dream material—with titanium dioxide (TiO2) (TMX). They reported development of a technique that controls oxygen vacancies via electron beam irradiation to greatly enhance the hydrogen evolution rate from water splitting.

Titanium dioxide (TiO2) is a stable and inexpensive photocatalyst, but it absorbs only the ultraviolet portion of sunlight, making visible-light utilization difficult, and the fast recombination of photogenerated electrons and holes results in low hydrogen production efficiency. To address this, research has actively focused on introducing defects to increase light absorption or introducing cocatalysts* to facilitate charge separation and transport.

*조촉매(cocatalyst): an auxiliary substance that works with the primary catalyst to promote electron transfer or chemical reactions and enhance catalytic performance.

The research team combined titanium dioxide with MXene, a highly conductive, thin layered material, and applied electron beam irradiation at room temperature and atmospheric pressure. By varying the MXene content and the absorbed dose, they found that an MXene content of 3 wt% and an absorbed dose of 500 kilogray (kGy) produced a high hydrogen evolution rate. The hydrogen evolution rate of this optimal photocatalyst (TMX3-500) increased by a factor of 5.25 (from 132 to 691 μmol g-1 h-1), and under the optimal aqueous pH condition (pH 4.03) hydrogen production increased substantially (3846 μmol g-1 h-1), achieving excellent performance as a photocatalyst for hydrogen evolution from water splitting.

In addition to experiments, the team theoretically elucidated the mechanisms behind this performance improvement using first-principles computational chemistry. Density functional theory (DFT) calculations showed that oxygen vacancies formed by the electron beam promoted light absorption and charge separation. The interface between titanium dioxide and MXene altered the electronic distribution, mitigating the strong binding of hydrogen to the catalyst surface and thermodynamically favoring hydrogen evolution.

*Oxygen Vacancy (Oxygen Vacancy): a vacancy created when an oxygen atom is missing from the crystal structure of a material.

Professor Seung-Hwa Yu of JBNU, who led the collaborative research, explained, “this achievement is significant because defect engineering using electron beams and photocatalyst interface design improve the low hydrogen evolution rates and aqueous stability issues of conventional titanium dioxide/MXene photocatalysts”. He added, “for future technological commercialization, complete water splitting using pure water and outdoor field demonstrations are necessary, and we plan to verify reaction conditions without sacrificial agents*, performance under actual sunlight, long-term stability, and the uniformity and economic feasibility of the electron beam irradiation process”.

*Sacrificial agent (Sacrificial agent): a substance that is oxidized or reduced preferentially in a photocatalytic reaction, consuming electrons or holes to facilitate the desired chemical reaction. In this study, methanol was used as the hole sacrificial agent.

Meanwhile, this research was carried out with support from the Regional University Outstanding Scientist Support Program funded by the Ministry of Education and promoted by the National Research Foundation of Korea, the Basic Research Laboratory Support Program (G‑Lamp), the 4th phase BK21 Project Division, and the main project of the pilot program for establishing an industry–academia–research cooperation platform supported by the Ministry of Science and ICT and promoted by the Korea Institute for Advancement of Technology. The results were published in the international journal in the fields of catalysis, environment, and energy, 'Applied Catalysis B: Environment and Energy' (IF 19.7, JCR top 1.7%) under the title ‘Tunable oxygen vacancy engineering via electron beam irradiation in TiO2/MXene: A combined experimental and DFT study on photocatalytic performance and hydrogen adsorption energetics’.. (https://doi.org/10.1016/j.apcatb.2026.127583)