Converting carbon dioxide into methane or ethane selectively

August 13, 2018

A research team led by Professor Su-Il In from Department of Energy Science and Engineering had succeeded in developing photo catalysts that can convert carbon dioxide into usable energy such as methane or ethane.

As carbon dioxide emissions increase, the Earth's temperature rises and interest in reducing carbon dioxide, the main culprit of global warming, has been increasing. In addition, the shift to reusable fuel for existing resources due to energy depletion is also drawing attention. In order to solve trans-national environmental problems, research on photocatalysts, which are essential in converting carbon dioxide and water into hydrocarbon fuels, is gaining attention.

Although many semiconductor materials with large band gaps are often used in photocatalyst studies, they are limited in absorbing solar energy in various areas. Thus, photocatalyst studies focusing on improving the photocatalyst structure and surface to increase solar energy absorption areas or utilizing two-dimensional materials with excellent electron transmission are under way.

Professor In's research team developed a high-efficiency photocatalyst that can convert carbon dioxide into methane (CH4) or ethane (C2H6) by placing graphene on reduced titanium dioxide in a stable and efficient way.

The photocatalyst developed by the research team can selectively convert carbon dioxide from a gas to methane or ethane. The results showed that its generation volume is 259umol/g and 77umol/g of methane and ethane respectively and its conversion rate is 5.2% and 2.7% higher than conventional reduced titanium dioxide photocatalysts. In terms of ethane generation volume, this result shows the world's highest efficiency under similar experimental conditions.

In addition, the research team proved for the first time that the pore moves toward graphene due to band bending phenomena visible from titanium dioxide and graphene interfaces through the international joint research conducted with the research team led by James R. Durrant at the Department of Chemistry of Imperial College London (ICL), UK using photoelectron spectroscopy.

The movement of the pore towards graphene activates reactions by causing electrons to gather on the surface of the reduced titanium dioxide and forms a large amount of radical methane (CH3) as polyelectrons engage in the reactions. The research team identified a mechanism for producing methane if this formed radical methane reacts with hydrogen ions and for producing ethane if the radical methane reacts with each other.

The catalyst material developed by the research team is expected to be applied to a variety of areas such as high-value-added material production in the future and be used to solve global warming problems and energy resource depletion issues by selectively producing higher levels of hydrocarbon materials using sunlight.

Professor In said, "The reduced titanium dioxide photocatalyst with graphene that has been developed this time has the advantage of being able to selectively produce CO2 as a usable chemical element such as methane or ethane. By conducting follow-up research that increases the conversation rate so that it can be commercialized, we will contribute to the development of technology for reducing carbon dioxide and turning it into a resource."

This research outcome was published on Thursday July 19, 2018 in the online edition of Energy & Environmental Science, an international journal on energy science.
-end-
For more information, contact:
Associate Professor Su-Il In
Department of Energy Science and Engineering
Daegu Gyeongbuk Institute of Science and Technology (DGIST)
E-mail: insuil@dgist.ac.kr

Associated Links

Research Paper on Journal of Energy & Environmental Science
Laboratory of Energy Science and Engineering at DGIST

Journal Reference

Su-il In, James R. Durrant, et al., "High-rate solar-light photoconversion of CO2 to fuel: controllable transformation from C1 to C2 products," Energy & Environmental Science July 2018.

DGIST (Daegu Gyeongbuk Institute of Science and Technology)

Related Graphene Articles from Brightsurf:

How to stack graphene up to four layers
IBS research team reports a novel method to grow multi-layered, single-crystalline graphene with a selected stacking order in a wafer scale.

Graphene-Adsorbate van der Waals bonding memory inspires 'smart' graphene sensors
Electric field modulation of the graphene-adsorbate interaction induces unique van der Waals (vdW) bonding which were previously assumed to be randomized by thermal energy after the electric field is turned off.

Graphene: It is all about the toppings
The way graphene interacts with other materials depends on how these materials are brought into contact with the graphene.

Discovery of graphene switch
Researchers at Japan Advanced Institute of Science and Technology (JAIST) successfully developed the special in-situ transmission electron microscope technique to measure the current-voltage curve of graphene nanoribbon (GNR) with observing the edge structure and found that the electrical conductance of narrow GNRs with a zigzag edge structure abruptly increased above the critical bias voltage, indicating that which they are expected to be applied to switching devices, which are the smallest in the world.

New 'brick' for nanotechnology: Graphene Nanomesh
Researchers at Japan advanced institute of science and technology (JAIST) successfully fabricated suspended graphene nanomesh (GNM) by using the focused helium ion beam technology.

Flatter graphene, faster electrons
Scientists from the Swiss Nanoscience Institute and the Department of Physics at the University of Basel developed a technique to flatten corrugations in graphene layers.

Graphene Flagship publishes handbook of graphene manufacturing
The EU-funded research project Graphene Flagship has published a comprehensive guide explaining how to produce and process graphene and related materials (GRMs).

How to induce magnetism in graphene
Graphene, a two-dimensional structure made of carbon, is a material with excellent mechani-cal, electronic and optical properties.

Graphene: The more you bend it, the softer it gets
New research by engineers at the University of Illinois combines atomic-scale experimentation with computer modeling to determine how much energy it takes to bend multilayer graphene -- a question that has eluded scientists since graphene was first isolated.

How do you know it's perfect graphene?
Scientists at the US Department of Energy's Ames Laboratory have discovered an indicator that reliably demonstrates a sample's high quality, and it was one that was hiding in plain sight for decades.

Read More: Graphene News and Graphene Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.