Guochuang Technology Instrument

The R&D team of Guochuang Scientific Instrument has launched the SuperXAFS series of desktop X-ray absorption spectrometers based on nearly 20 years of research experience in X-ray spectroscopy of large scientific devices. This series provides users with experimental data comparable to synchrotron radiation XAFS with high-quality X-rays, excellent energy resolution, and ultra precision linkage scanning system.

▲ EXAFS characterization results of UOF-TFP

Nuclear energy, due to its high energy density and low carbon pollution, is considered an effective alternative energy source. However, the sustainable development of nuclear energy is still severely constrained by uranium shortages and inadequate supply chains. Therefore, conducting research on separating uranium from old or new sources is of great significance.Team led by Luo Feng from Donghua University of TechnologyA two-dimensional uranium organic framework structure was proposed to achieve uranium separation by combining in situ formed π - conjugated organic ligands with uranium.

In the study, five organic ligands were screened and high-quality uranium L-edge EXAFS data were obtained using a SuperXAFS desktop X-ray absorption spectrometer. The coordination structure of uranium was quantitatively analyzed through fine spectrum fitting, and it was found that 1,3,5-triaoyl (H3TFP) is the best ligand for constructing uranium organic frameworks because uranium can form stable planar coordination structures with H3TFP. The shorter bond lengths are the two U=O bonds of UO2, while the longer bond lengths are the six planar U-O bonds formed by uranium and H3TFP. This selective and stable coordination structure enables H3TFP to achieve complete adsorption of uranium in solution.

EXAFS characterization results of MPc (M=Fe, Co, Ni) (dashed line represents test results, red line represents fitting results)

The electrochemical carbon dioxide reduction reaction has the potential to convert excess carbon dioxide in the atmosphere into value-added products such as formate, ethylene, and ethanol. However, so far, the selectivity of reaction products has been limited due to the lack of electrocatalysts that can effectively activate carbon dioxide and continuously grow carbon chains, with products containing up to four carbon atoms. The synthesis of carbon dioxide and multi carbon products through electrochemical cascade reactions is of great significance.Professor Zheng Gengfeng's team from Fudan UniversityThe local coordination structure of a class of metal phthalocyanine (MPc) materials was studied using a SuperXAFS desktop X-ray absorption spectrometer through high-quality EXAFS spectrum testing.

In the study, it was found that MPc (M=Fe, Co, Ni) materials exhibit a [MN4] coordination structure, which allows NiPc materials to oxidize ethylene to 2-bromoethanol in a bromine containing electrolyte. At the counter electrode of the reaction, FePc reduces nitrite ions to ammonia, which then reacts with 2-bromoethanol to produce triethanolamine. And combining this reaction with the reduction of CO2 to ethylene can achieve the reduction of CO2 to six carbon compounds.

XANES characterization results before and after molten salt electro etching

MXene materials have gained widespread attention in the field of energy storage and conversion in recent years due to their two-dimensional layered structure, high conductivity, and hydrophilic surface. The commonly used preparation method for two-dimensional MXene is hydrofluoric acid or fluoride hydrochloric acid solution etching, which often introduces - F functional groups that affect the conductivity of the material; The Lewis molten salt etching method reported in recent years inevitably leaves metal impurities in MXene, which must be removed by oxidizing acids in subsequent applications or surface modification processes.Researcher Wang Jianqiang's team at Shanghai Institute of Applied PhysicsWe have developed a molten salt electro etching method (MS-E-etching) to prepare two-dimensional layered material Ti3C2Tx (T=O, S), and with the help of a SuperXAFS desktop X-ray absorption spectrometer, we have studied the reaction mechanism of molten salt electro etching through precise Ti K-edge XANES testing.

The test results show that the peak position of Ti3C2Tx is significantly shifted towards higher energy compared to Ti3AlC2, indicating that Ti is oxidized during the reaction process; From the analysis of the spectral structure, it can be seen that the near edge characteristics of the peaks of the two samples are similar, but differ greatly from Ti foil and TiO2, thus proving that the local structure of Ti remains consistent before and after molten salt electro etching. From the spectral results, it can be inferred that the mechanism of molten salt electro etching is that during the oxidation process of Ti3AlC2 phase, due to the weaker Ti Al bond than Ti-C bond, Al atoms selectively combine with Cl - in the molten salt to form AlCl3. The volatilization of AlCl3 at 450 ℃ provides the driving force for the outward diffusion of Al atoms. Continuing to add Li2O/Li2S to the system, MXenes containing various functional groups such as - O/- S were obtained through substitution reactions of functional groups at high temperatures. Among them, Ti3C2 modified with - O functional group exhibits excellent electrochemical performance in 1M H2SO4 solution.