Raman Spectroscopy of Potassium Titanates: Their Synthesis, Hydrolytic Reactions, and Thermal Stability

Abstract

The majority of the potassium titanates described in the literature were synthesized, and their Raman spectra recorded. The identity of the compounds K2TiO3, K2Ti2O5, K2Ti4O9, K2Ti6O13, and K2Ti8O17 was confirmed by x-ray diffraction. Raman spectroscopy was then used to study the hydrolysis, under different conditions, of K2Ti2O5 and of K2Ti4O9. On drying of the hydrolysis products, the following species were found to form: K2(H2O)0.66 Ti8O16(OH)2, K1.33(H2O)0.33Ti4O8.33(OH)0.67, and H2Ti8O17. On ignition at temperatures of 500–600°C these species converted, respectively, to K2Ti8O17, K2Ti6O13, and TiO2(B). Raman spectroscopy was used to establish that (1) K6Ti4O11 consists of a mixture of K2TiO3 and a new compound K4Ti3O8; (2) K2Ti3O7 consists of a mixture of K2Ti2O5 and K2Ti4O9, and (3) K2Ti5O11 consists of a mixture of K2Ti4O9 and K2Ti6O13. The temperature of decomposition and the identity of the products of the thermal decomposition of K2Ti8Ol7, K2Ti4O9, K2Ti2O5, and K4Ti3O8 were determined by Raman spectroscopy. The XRD data of the newly identified compounds are reported.

NO selective reduction by hydrogen on potassium titanate supported palladium catalyst

“…2. Raman bands at 280, 390, 450, 650 and 860 cm À1 can be observed, which agree with the characteristic bands of K 2 Ti 6 O 13 [17]. The band at 900 cm À1 is attributed to the four coordinated Ti-O stretching modes that stuck out into the interlayer spaces [18].…”

Corrosion behavior of Ti3AlC2 in molten KOH at 700 °C

“…Agreed with the Raman result, potassium atoms are detected by EDS in the samples of group B. Among several types of potassium titantates, K 2 Ti 6 O 13 is relative stable and easily hydrolyzed to amorphous TiO 2 [27]. Therefore, it is reasonable to conclude that amorphous K 2 Ti 6 O 13 transforms to amorphous TiO 2 in the acid solution by the following reactions: O 13 nanowires have been fabricated by using potassium titanates as precursor, which are prepared through a facile hydrothermal method, and followed with an acid treatment and finally dried at 70 ℃ for 12 h [30].…”

“…Firstly, a large amount of amorphous graphite exists in the corroded phase, which is strongly demonstrated by the peaks located at ~1348 cm 1 and ~1580 cm 1 appearing in Raman spectra of all the corroded samples (not shown). Besides amorphous graphite, there are potassium titanates (K 2 Ti 6 O 13 ) [27] and rutile (TiO 2 ) detected in group A and group B as shown in Fig. 2 and Fig.…”

“…In both figures, the peaks are gradually left-shifted and sharpened as KOH ratio increases. According to the Raman spectra in the literature [27], the sharp peaks labeled with numbers in Fig. 2 belong to K 2 Ti 6 O 13 , which is sensitive to Raman spectroscopy [28,29].…”

Electrochemical Synthesis of Potassium Titanate Nanowires in Molten Salts with Good Li+-Intercalation Performance

“…It is worth noting that the Raman scattering data obtained in this work is consistent with previous reports. 17,18 The disordered carbon (D-band) and graphite carbon (G-band) in the Raman spectrum are the two prominent peaks located at 1337 and 1587 cm −1 . These peaks arise from the amorphous carbon coating layer.…”