\”Father Mxene of\” Yury Gogotsi: – the text read Mxene Raman spectroscopy
, as a large class of 2D transition metal carbide, nitride or carbonitride, causing great concern to researchers, mainly by selective etching of the corresponding phase A precursor atomic layer is patterned MAX etching, forming a layered structure. 2D, its versatility in chemical structure and have a competitive advantage with such MXenes and other two-dimensional materials in high conductivity, large surface area, particularly in a variety of applications is has broad application prospects in the field of energy conversion and energy storage batteries, super capacitors and catalysis. On the basis of previous studies found that Synthesis of precursors and etching conditions will affect the composition of MXene , such as, MXene Different surface groups may change the Fermi level, and change the material strip gap; intercalation substance and sheet size can also affect the optical properties and electrical conductivity of MXene. Therefore, How to accurately characterize the MXene composition, structure and morphology of great scientific significance. But in terms of detailed characterization work MXene also rarely reported. Recently, United States Drexel (Drexel) University, has a \”father Mxene,\” said the Professor Yury Gogotsi team use [123 ] Ti3C2Tx multi-wavelength Raman spectroscopy carried out research, its main synthetic methods, the relationship between the state of the material (single, colloidal solution, stacked sheets) and the intercalated material and the Raman spectrum changes from fine spectrum MXene obtain vibration characteristics difference, thereby determining the composition, structure and morphology of Mxene. The study mainly emphasizes versatility in MXene Raman spectroscopy analysis, as well as the importance of choosing the right conditions to obtain accurate information and Raman spectroscopy avoid artifacts. The research results entitled \”Raman Spectroscopy Analysis of of Ti3C2Tx MXene the Structure and Surface Chemistry\” is published in \” Chemistry of materials \” on (see the text description link). In order to study author Ti3C, The relationship between the state of the material (single, colloidal solution, stacked sheets) and the intercalated material and the Raman spectrum 2Tx synthetic methods. Etching using different ways (1 hydrofluoric acid, a mixed solution of hydrochloric acid; 2 mixed solution of hydrofluoric acid and water; 3 mixed solution of lithium fluoride and hydrochloric acid) and various concentrations of an aqueous solution of HF (5, 10, 20 and 30%), powders of Ti3AlC2 etching, the prepared materials Ti3C2Tx different forms. In the Raman spectrum, MXene spectral characteristics has four main areas: formant region sheet; the Tx region; carbon region. It may be characterized according to the feature region MXene peak displacement, intensity and width characteristics.
Raman peaks associated form Raman spectra of different materials Morphological Ti3C2Tx found that the sample type is not
AIg ( C) peak showed different peak displacement. The multilayer Ti3C2T A1g (C) since the interlayer spacing is small and the accumulation effect, the vibration is limited, which is the minimum peak shift. A1g Ti3C2T film (C) of the peak due to the introduction of the intercalating agent to expand the spacing between layers, such AIg (C) to move the peak 720 cm-1. Deposited on Si / SiO2 substrate monolithically Ti3C2Tx peak shift to upgrade to 720 736 cm-1, and since the outer surface of the substrate side of the vibration is restricted, leading to the emergence of asymmetric peak. MXene MXene solution and the clay since the sheet is surrounded by H2O molecules, limited by the small, so the peak shifts to a higher number (726 cm-1) waves. Another aspect of the features associated with is A1g (C) / Alg (Ti, C, O) peak ratio ; Ti3C2Tx in the multilayer structure whose value is equal to 1.1, indicating that the sheet stacking parent Ti3C2Tx MAX similar. When the ratio will increase to 1.2, which means that the interaction strength between the sheet of randomly oriented sheet due to weakened. MAX compared to the parent phase, post-etch layer M and X ordering reduced; therefore, the entire sheet of Alg (Ti, C, O) of vibration will diminish. The single sheet A1g (C) / A1g (Ti, C,O) ratio of 0.9, which is mainly due to the overall strength of the sheet caused by vibration A1g (Ti, C, O) is increased. In the aqueous dispersed solution, since the flakes in a solution and randomly oriented continuous movement, causing Alg (Ti, C, O) peak has almost completely disappeared.