Alfa Chemistry provides testing services for the element composition and content of graphene. The metal impurities contained in natural graphite from different places are different, such as iron, cobalt, nickel and etc. The impurities contained in graphene powders obtained by different production processes are also very different. For example, the high content of S and Cl in graphene powders prepared by redox methods will affect its performance as electrode materials. Alfa Chemistry uses a variety of methods to detect the elemental composition of crude graphene and its devices.
Our Instrument Platforms for Element Analysis
- X-Ray Photoelectron Spectrometer (XPS)
XPS can be used for qualitative analysis and semi-quantitative analysis. Generally, information such as the element composition, chemical state and molecular structure of the sample can be obtained from the peak position and peak shape of the XPS spectrum. XPS can detect all elements in the periodic table except hydrogen and helium. The general detection limit is 0.1% (atomic percentage).
Figure 1. Schematic diagram of X-ray photoelectron spectrometer
- Inductively Coupled Plasma Spectrometer
According to the different detectors, inductively coupled plasma spectrometer can be divided into inductively coupled plasma emission spectrometer (ICP-OES) and inductively coupled plasma mass spectrometer (ICP-MS). Both can measure most of the elements in the periodic table. The latter is higher in detection ability than the former because the ICP light source has good atomization, excitation and ionization capabilities. ICP can test multiple elements at the same time with high sensitivity, low detection limit and wide test range.
Figure 2. Schematic diagram and actual photograph of an ICP assembly. (Hou X.D, et al. 2016)
- Energy Dispersive X-ray Spectrometer
Energy dispersive X-ray spectrometers are often used for scanning electron microscopy or transmission electron microscopy for micro-area component analysis. The main component of the X-ray energy spectrometer is the Si (Li) semiconductor detector. It cannot be used to analyze ultra-light elements (O, N, C and etc). The reason is that the resolution of the detector is not high enough.
Figure 3. Schematic diagram of energy dispersive X-ray spectrometer
Detectable samples include:
Graphene and its derivatives.
Testing Standards
GB/T 30544.13-2018 ISO/TS 80004-13:2017(en): Graphene and Related Two-dimensional (2D) Materials.
ASTM E1613-2004 Standard Test Method for Detecting Lead by ICP-AES, FAAS or GFAAS Technology.
Why Us?
- ISO/IEC17025 international laboratory management system.
- Various testing instruments and high-level, professional and experienced technical team.
- Fast cycle time and complete experimental programs.
References
- Gorzalski A.S, et al. (2017). "Elemental composition of membrane foulant layers using EDS, XPS, and RBS." Journal of Membrane Science. 522(14), 31-44.
- Hou X.D, et al. (2016). "Inductively Coupled Plasma Optical Emission Spectrometry." Encyclopedia of Analytical Chemistry.
