Advanced Method for Analyzing Graphene Oxide
July 1, 2019 | Tomsk Polytechnic UniversityEstimated reading time: 2 minutes
Researchers from Tomsk Polytechnic University have developed a reliable method for analyzing the reduction of graphene oxide microregions. In contrast to earlier proposed methods based on Raman spectroscopy, this advanced method provides more exact data about unique properties of certain areas of the material of only a few micrometers in size.
Image Caption: Raman spectrum of graphene oxide with the designation of peaks, and the scheme of the experiment
The international research team led by Professor Raul Rodrigez from TPU School of Chemistry & Applied Biomedical Sciences and Professor Evgeniya Sheremet from TPU School of High Energy Physics is developing new field - optical nanospectroscopy, as well as plasmon and sensor materials development for biomedicine and electronics.
According to Professor Sheremet, the study of unique physical-chemical properties of graphene oxide is still relevant despite many studies in the area. Graphene oxide has a graphene structure with attached oxygen-containing functional groups. The number of these groups strongly influences the properties of the material.
"The fewer oxygen groups remain on the surface of graphene oxide, the higher its reduction. This criterion influences whether the material will be hydrophilic and a dielectric due to polar groups, or it will be more similar to graphene, i.e. hydrophobic and a conductor," says TPU professor.
There are several ways to evaluate the reduction, for example, X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy. However, these methods work only with large areas of materials, whereas microregions are required to process graphene oxide to be applied in electronics. Therefore, TPU scientists investigate laser-reduced graphene oxide, the size of reduced areas can be less than several micrometers.
‘We were looking for a method that allowed us to obtain at least micron resolution, such as Raman spectroscopy,’ explains Evgeniya Sheremet.
Reduced graphene oxide (rGO) was obtained under different laser powers in the range from 0.1 to 10 mW. Then, the researchers investigated reduced areas by using Raman spectrometer and a joint current sensing atomic force microscopy (CSAFM). Raman spectroscopy is widely used for the study of many properties of carbon materials, especially graphene, including mechanical stress, the number of defects, and the type of alloying. However, existing approaches suitable for graphene do not work for graphene oxide since its lattice has a greater number of defects. The analytical methods lose sensitivity in this case.
‘Usually, first-order peaks are analyzed in carbon materials but for graphene oxide, they do not provide reliable results. Therefore, we analyzed the areas of high frequencies and found a clear pattern. The relative intensity of second-order peaks decreases with increasing the extent of reduction. Notably, there is a strong correlation with the conductivity of the material, i.e. we can use Raman signal to assess the reduction of graphene oxide. This is a more reliable method than the earlier proposed ones,’ emphasizes the professor.
Moreover, using nanospectroscopy approaches, this technique can be used for analyzing nanoscale areas.
Suggested Items
Groundbreaking Ceremony Marks the Beginning of a New Era for Newccess Industrial; The Construction of the MINGXIN Building
04/12/2024 | Newccess IndustrialOn a clear and sunny day in March, the groundbreaking ceremony for the MINGXIN Building took place in Shenzhen, China. This moment marked the official commencement of construction for a project that will reshape the semiconductor materials industry.
The Need for a Holistic Global Sustainability Standard
04/10/2024 | Michael Ford, Aegis SoftwareNo one can deny that the resources of our fragile planet are finite. The environment seems like a third party, subject to constant degradation. We’re acutely aware of the effects of pollution on our climate, and despite our “throw-away” culture, recycling and recovery of materials has remained relatively expensive, even as we use more energy just to survive.
iNEMI Publishes Four Roadmap Topics
04/04/2024 | iNEMIThe International Electronics Manufacturing Initiative (iNEMI) announces the availability of the first roadmap topics in the new iNEMI Roadmap format. Printed circuit boards, sustainable electronics, smart manufacturing, and mmWave materials and test are now available online.
Insulectro’s 'Storekeepers' Extend Their Welcome to Technology Village at IPC APEX EXPO
04/03/2024 | InsulectroInsulectro, the largest distributor of materials for use in the manufacture of PCBs and printed electronics, welcomes attendees to its TECHNOLOGY VILLAGE during this year’s IPC APEX EXPO at the Anaheim Convention Center, April 9-11, 2024.
Checking In With ICAPE Group
04/03/2024 | Nolan Johnson, I-Connect007ICAPE Group’s field application engineer Erik Pederson drills down on sustainability, supply chain resiliency, and what value engineering really looks like in this exclusive interview. Founded in 1999, European-based ICAPE Group provides 21 million printed circuit boards and over six million technical parts to manufacturers every month. With 30 PCB manufacturing partners globally and 50 partners providing a wide array of technical parts, ICAPE Group has operations in China, Taiwan, Thailand, South Korea, Vietnam, South Africa, Europe, Mexico, and the United States. The company also focuses on the value proposition for its customers.