Sonochemical Synthesis and Characterization of the Biphasic Compound Na2Ti3O7/ Na2Ti6O13

Abstract

This study processed and characterized the biphasic ceramics Na 2 Ti 3 O 7 /Na 2 Ti 6 O 13 that were obtained from semi-crystalline nanoparticles synthesized using sonochemical methods. Structural characterization techniques, such as X-ray diffraction and Raman spectroscopy, were used to identify the crystalline phases present. The Rietveld refinement revealed, among other structural parameters, the presence of two crystalline phases in compositions of 55.90% and 44.10% for sodium hexatitanate and trititanate, respectively. Via Raman spectroscopy, the presence of the main vibrational modes that correspond to the phases present in biphasic ceramics was confirmed. Finally, by using complex impedance spectroscopy, a decrease in the electrical resistance of both the grain (10 6 Ω-10 4 Ω) and its boundary (10 8 Ω -10 5 Ω) under increasing temperature was identified.

Significant Enhancement in the Electrochemical Performances of a Nanostructured Sodium Titanate Anode by Molybdenum Doping for Applications as Sodium-Ion Batteries

“…As shown in Figure d, the pure NTO and MoNTO-10 samples exhibit the characteristic peaks of the Na 2 Ti 6 O 13 phase along with few peaks of Na 2 Ti 3 O 7 . − Meanwhile, the MoNTO-15 consists only the characteristic peaks of the Na 2 Ti 6 O 13 phase, which is in fact in accordance with the XRD results. The presence of the Na 2 Ti 3 O 7 phase can be detected by the characteristic band located at ∼306, ∼347, ∼452, ∼852, and ∼884 cm –1 , which can be ascribed to the Na–O–Ti bond stretching and scissors-type vibrations of O–Ti–O bonds. − On the other hand, the Raman spectra of the Na 2 Ti 6 O 13 phase is dominated by lower frequency bands obtained at ∼110, ∼138, ∼197, ∼225, and ∼275 cm –1 , which are very strong and well resolved. Generally, the vibrations obtained in the region below 400 cm –1 and above 600 cm –1 are related to the sodium and displacements of the TiO 6 octahedron, respectively .…”

“…The presence of the Na 2 Ti 3 O 7 phase can be detected by the characteristic band located at ∼306, ∼347, ∼452, ∼852, and ∼884 cm –1 , which can be ascribed to the Na–O–Ti bond stretching and scissors-type vibrations of O–Ti–O bonds. − On the other hand, the Raman spectra of the Na 2 Ti 6 O 13 phase is dominated by lower frequency bands obtained at ∼110, ∼138, ∼197, ∼225, and ∼275 cm –1 , which are very strong and well resolved. Generally, the vibrations obtained in the region below 400 cm –1 and above 600 cm –1 are related to the sodium and displacements of the TiO 6 octahedron, respectively . Thus, the bands located at ∼658 and ∼680 cm –1 can be ascribed to the Ti–O–Ti stretching in edge-shared TiO 6 octahedra .…”

“…Generally, the vibrations obtained in the region below 400 cm −1 and above 600 cm −1 are related to the sodium and displacements of the TiO 6 octahedron, respectively. 26 Thus, the bands located at ∼658 and ∼680 cm −1 can be ascribed to the Ti−O−Ti stretching in edge-shared TiO 6 octahedra. 23 Moreover, the most energetic band located at ∼872 cm −1 is due to the short Ti−O bond vibrations in the tunneled structure of Na 2 Ti 6 O 13 .…”

MXene-derived Ti3C2–Co–TiO2nanoparticle arraysviacation exchange for highly efficient and stable electrocatalytic oxygen evolution

“…15 LM-Na-Co-TO NA revealed intrinsic peaks of sodium titanate at B270 and B670 cm À1 (Fig. S1, ESI †), 22 which disappeared after cation exchange, confirming that Na + was successfully removed. The ICP-OES results further confirmed the almost complete removal of Na + (Table S1, ESI †).…”

Vibrational and electronic properties of Na2Ti6O13

“…These values are in good agreement with previous reports. [ 11,22,45 ] The selected area electron diffraction of the microcrystal displayed in Figure 1B is presented in Figure 1C. A detailed analysis of the selected area electron diffraction pattern with the HRTEM image reveals that the longest side of elongated microcrystal is preferentially along the crystallographic direction, denoted as , and the direction in the plane of the image ( crystallographic direction).…”