X-band Benchtop Electron Paramagnetic Resonance / Electron Spin Resonance (EPR / ESR) Spectroscopy
The CIQTEK EPR200M is a newly designed benchtop EPR spectrometer specializing in the qualitative and quantitative analysis of free radicals, special valence transition metal ions, and material doping and defects. It is an excellent research tool for real-time monitoring of chemical reactions, in-depth evaluation of material properties, and exploration of pollutant degradation mechanisms in environmental science.
The EPR200M adopts a compact design and highly integrates the microwave source, magnetic field, probe, and main controller, ensuring sensitivity and stability while being compatible with diverse experimental needs. The user-friendly interface allows even first-time users to start quickly, making this advanced instrument truly easy to use.
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The design integrates the optimized microwave, magnetic field, probe, and central control module, making the EPR machine easier to transport, space-saving, and adaptable to a broader range of test environments.
Sweeping ranges: -100 to 6500 Gauss, with over-zero field scanning possible.
Magnetic field: air-cooled and compact.
Magnetic field scanning control tech: uniformity of better than 50 mG in the sample area, guaranteeing high-quality spectra.
Ultra-low noise microwave generation technology, combined with high-quality microwave probes and weak signal detection, guarantees the high sensitivity of the EPR spectrometer.
Experienced technical and application engineers provide professional services to help customers master the EPR analysis and attribution of EPR spectra, even for beginners.
EPR Application Cases
EPR Detection of Free Radicals
Free radicals are atoms or groups with unpaired electrons that are formed when a compound molecule is subjected to external conditions such as light or heat and the covalent bonds are split. For more stable free radicals, EPR can detect them directly and quickly. For short-lived free radicals, they can be detected by spin trapping. For example, hydroxyl radicals, superoxide radicals, single-linear oxygen light radicals, and other radicals produced by photocatalytic processes.
Paramagnetic Metal lons
For transition metal ions (including iron, palladium, and platinum group ions with unfilled 3d, 4d, and 5d shell respectively) and rare earth metal ions (with unfilled 4f shell), these paramagnetic metal ions can be detected by EPR spectrometer due to the presence of the single electrons in their atomic orbitals, thus obtaining the valence and structure information. In the case of transition metal ions, there are usually multiple valence states and spin states with high and low spins. Parallel modes in a two-mode cavity allow detection of the integer spin regime.
Conduction Electrons in Metal
The EPR line shape that conducts electrons is related to the size of the conductor, which is of great significance in the field of lithium-ion batteries. EPR can non-invasively probe the interior of the battery to study the deposition process of lithium in a close-to-real situation, from which the microscopic size of metallic lithium deposits can be inferred.
Material Doping And Defects
Metallofullerenes, as new nanomagnetic materials, have significant application value in magnetic resonance imaging, single-molecule magnets, spin quantum information, and other fields. Through EPR technology, the electron spin distribution in metallofullerenes can be obtained, providing an in-depth understanding of the ultrafine interaction between spin and the magnetic nucleus of metals. It can detect changes in spin and magnetism of metallofullerenes in different environments. (Nanoscale 2018, 10, 3291)
Photocatalysis
Semiconductor photocatalytic materials have become a hot research topic due to their potential applications in environmental, energy, selective organic transformation, medical, and other fields. EPR technology can detect active species generated on the surface of photocatalysts, such as e-, h+, •OH, O2, 1O2, SO3, etc. It can detect and quantify vacancies or defects in photocatalytic materials, assist in studying active sites and reaction mechanisms of photocatalytic materials, optimize parameters for subsequent photocatalytic application processes, detect active species and their proportions during photocatalysis, and provide direct evidence for system reaction mechanisms. The figure shows the EPR spectra of 0.3-NCCN and CN, indicating that 0.3-NCCN contains more unpaired electrons, higher crystallinity, and an extended p-conjugated system, resulting in better photocatalytic performance. (International Journal of Hydrogen Energy, 2022, 47: 11841-11852)
Parallel magnetic field signal of a diamond |
Signal of TEMPOL after deaeration |
Various free radical signals |
Cu valence |
EPR ProCt. is the control software for operating all CIQTEK EPR spectrometers. The interface and utilities are customized for both new and experienced users to set up experiments efficiently. While EPR ProCt. includes basic data processing tools, it allows data file transfer to the data processing software EPR ProPr. by one click.
Independent from the control software, EPR ProPr. is for processing EPR spectra and time-domain data. EPR ProPr. can be installed on any laptop for easy access, providing a toolbox that meets various requirements.