The Electronics Industry Has Been Waiting... UNIST Develops Mass Synthesis Technology for 'Graphene' with Excellent Electrical Conductivity and High Added Value

Professor Jang Ji-hyun's Team Develops Catalytic Reduction-Based Graphene Oxide Reduction Technology

Accelerating Commercialization of Electronic Materials with Excellent Electrical Conductivity and Transparent Electrodes

Schematic diagram of graphene oxide reduction method using a catalyst.

[Asia Economy Yeongnam Reporting Headquarters Reporter Kim Yong-woo] A new technology has been developed that can mass-produce high-quality graphene with electrical conductivity suitable for use as electronic materials.

The commercialization of flexible and transparent graphene-based display electrodes is expected to be accelerated.

The research team led by Professor Jang Ji-hyun of the Department of Energy and Chemical Engineering at Ulsan National Institute of Science and Technology (UNIST) developed a catalyst reduction-based technology that can mass-produce high-quality graphene without emitting carbon gases.

The method involves mass-producing easily synthesized graphene oxide and then removing (reducing) the oxygen from the graphene oxide to obtain high-quality graphene.

By using a copper iron oxide catalyst (CuFeO2) that selectively removes only oxygen, the team solved the existing problem where carbon, the constituent element of graphene, was also removed and carbon gases were emitted.

Graphene is a planar material where carbon atoms are bonded in a hexagonal honeycomb structure. It conducts electricity better than copper, a wire material, and is transparent and flexible, making it a promising new electrode material.

However, it is not easy to mass-produce high-quality graphene with excellent electrical conductivity suitable for electronic materials.

The method of attaching vapor-phase graphene precursors one by one onto a metal substrate (CVD; Chemical Vapor Deposition) is difficult for mass production, while the method of synthesizing graphene by reducing graphene oxide is easy for mass production but has the disadvantage of lower quality.

The synthesis method developed by Professor Jang’s team has the advantage of producing high-quality graphene with excellent electrical conductivity, even though it is a graphene oxide reduction method.

The graphene produced by the developed synthesis method showed electrical conductivity more than 8 times higher compared to graphene produced by the CVD method, and 246 times higher electrical conductivity compared to the conventional graphene oxide reduction method.

This was possible thanks to the catalyst that selectively removes only oxygen and the identified synthesis conditions such as atmospheric pressure and temperature.

In the typical graphene oxide reduction process, carbon dioxide (CO2) is generated simultaneously, creating vacancies where carbon (C) atoms are removed from the graphene, which lowers electrical conductivity. In contrast, the catalyst used by the research team selectively removes oxygen and also repairs the graphene structure damaged by oxygen, resulting in high-quality graphene.

(From the top right clockwise) Professor Jang Jihyun, Professor Peng Ding, Researcher Kwak Myungjun, Researcher Yoon Jongchul, Researcher Kang Kyungnam.

Jongcheol Yoon, the first author and a doctoral researcher in the Department of Energy and Chemical Engineering at UNIST, proudly stated, “When we actually measured the amount of carbon dioxide generated to verify this, the CO2 generation was reduced by nearly 100 times compared to the existing method.”

Additionally, this technology uses a catalyst made of inexpensive iron and copper at a relatively low temperature of 300℃. Previously, heat treatment above 2000℃ was required to restore the graphene structure damaged by oxygen.

Professor Jang Ji-hyun explained, “We have introduced for the first time a technology that transforms graphene oxide into high-quality graphene at relatively low temperatures using a carbon dioxide conversion catalyst. If commercialized, it will be possible to mass-produce high-value-added high-quality graphene cheaply.”

This research was conducted jointly with Professor Feng Ding of the Department of Materials Science and Engineering (Group Leader of the IBS Center for Multidimensional Carbon Materials). The research results were published in ACS Nano on July 2.

The research was supported by the National Research Foundation of Korea (NRF) through the Mid-career Researcher Support Program, the project for developing photoelectrochemical hydrogen production technology and systems for onsite hydrogen refueling stations, and the Institute for Basic Science (IBS).

This content was produced with the assistance of AI translation services.