Magneli Phase Titanium Oxide: Electrochemical Routes and Characterisation

2014 ◽  
Vol 61 (4) ◽  
pp. 393-404 ◽  
Author(s):  
P. Dunne ◽  
M. Mieszala ◽  
V. Le Nader ◽  
L. Philippe ◽  
J. Michler
2009 ◽  
Vol 1218 ◽  
Author(s):  
Shunta Harada ◽  
Katsushi Tanaka ◽  
Haruyuki Inui

AbstractThermoelectric properties of a homologous series of Magnéli phase titanium oxides TinO2n-1 (n = 2, 3..) have been investigated. Dense polycrystalline specimens with nominal composition of TiO2-x (x = 0.10, 0.20) have been prepared by conventional hot-pressing. X-ray diffraction analysis has revealed that prepared specimens are slightly reduced during hot-pressing. Electrical conduction is of n-type for all prepared titanium oxides and electrical resistivity and absolute values of Seebeck coefficient decrease with increasing oxygen deficiency. The carrier concentration of Magnéli phase titanium oxide increases with increasing oxygen deficiency. Lattice thermal conductivity decreases with increasing oxygen deficiency by more than 60% at room temperature and 40% at 773K compared to TiO2, which can be due to the presence of dense planar defects. The largest thermoelectric figure of merit Z, 1.6×10-4 K-1 at 773K, was obtained in TiO1.90 hot pressed specimen.


2017 ◽  
Vol 5 (37) ◽  
pp. 19991-19996 ◽  
Author(s):  
Xuecheng Cao ◽  
Zhihui Sun ◽  
Xiangjun Zheng ◽  
Jinghua Tian ◽  
Chao Jin ◽  
...  

The application of MnCo2O4 (MCO) decorated Ti4O7 as a carbon-free cathode for Li–O2 batteries is reported for the first time. The high performance of Ti4O7/MCO cathode is attributed to the high electronic conductivity of Ti4O7, the high electrocatalytic activity of MCO and the synergistic interaction between Ti4O7 and MCO toward ORR and OER.


Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6833 ◽  
Author(s):  
Simonas Ramanavicius ◽  
Arunas Ramanavicius

In this review article, attention is paid towards the formation of various nanostructured stoichiometric titanium dioxide (TiO2), non-stoichiometric titanium oxide (TiO2−x) and Magnéli phase (TinO2n−1)-based layers, which are suitable for the application in gas and volatile organic compound (VOC) sensors. Some aspects related to variation of sensitivity and selectivity of titanium oxide-based sensors are critically overviewed and discussed. The most promising titanium oxide-based hetero- and nano-structures are outlined. Recent research and many recently available reviews on TiO2-based sensors and some TiO2 synthesis methods are discussed. Some promising directions for the development of TiO2-based sensors, especially those that are capable to operate at relatively low temperatures, are outlined. The applicability of non-stoichiometric titanium oxides in the development of gas and VOC sensors is foreseen and transitions between various titanium oxide states are discussed. The presence of non-stoichiometric titanium oxide and Magnéli phase (TinO2n−1)-based layers in ‘self-heating’ sensors is predicted, and the advantages and limitations of ‘self-heating’ gas and VOC sensors, based on TiO2 and TiO2−x/TiO2 heterostructures, are discussed.


ACS Omega ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 5304-5309 ◽  
Author(s):  
Geon-Woo Lee ◽  
Byung Hoon Park ◽  
Masoud Nazarian-Samani ◽  
Young Hwan Kim ◽  
Kwang Chul Roh ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 829
Author(s):  
Didem C. Dogan ◽  
Jiye Choi ◽  
Min Ho Seo ◽  
Eunjik Lee ◽  
Namgee Jung ◽  
...  

In this study, we address the catalytic performance of variously sized Pt nanoparticles (NPs) (from 1.7 to 2.9 nm) supported on magnéli phase titanium oxide (MPTO, Ti4O7) along with commercial solid type carbon (VXC-72R) for oxygen reduction reaction (ORR). Key idea is to utilize a robust and electrically conductive MPTO as a support material so that we employed it to improve the catalytic activity and durability through the strong metal-support interaction (SMSI). Furthermore, we increase the specific surface area of MPTO up to 61.6 m2 g−1 to enhance the SMSI effect between Pt NP and MPTO. After the deposition of a range of Pt NPs on the support materials, we investigate the ORR activity and durability using a rotating disk electrode (RDE) technique in acid media. As a result of accelerated stress test (AST) for 30k cycles, regardless of the Pt particle size, we confirmed that Pt/MPTO samples show a lower electrochemical surface area (ECSA) loss (<20%) than that of Pt/C (~40%). That is explained by the increased dissolution potential and binding energy of Pt on MPTO against to carbon, which is supported by the density functional theory (DFT) calculations. Based on these results, we found that conductive metal oxides could be an alternative as a support material for the long-term fuel cell operation.


2020 ◽  
Vol 1 (4) ◽  
Author(s):  
Peizeng Yang ◽  
Yaye Wang ◽  
Junhe Lu ◽  
Viktor Tishchenko ◽  
Qingguo Huang ◽  
...  

This study examined the degradation of perfluorooctanesulfonate (PFOS) in electrochemical oxidation (EO) processes in the presence of trichloroethylene (TCE). The EO experiment was performed in a gas-tight reactor using Magnéli phase titanium suboxide (Ti4O7) as the anode. The experimental data demonstrated that 75% of PFOS (2 μM) was degraded at 10 mA/cm2 current density in 30 min without TCE present in the solution, while the presence of 76 μM TCE apparently inhibited the degradation of PFOS, reducing its removal down to 53%. Defluorination ratio suggested that PFOS was significantly mineralized upon EO treatment, and it appeared to be not influenced by the presence of TCE. The respective pseudo-first order rate constants (kobs) of PFOS removal were 0.0471 and 0.0254 min-1 in the absence and presence of TCE. The degradation rates of both PFOS and TCE increased with current density rising from 2.5 to 20 mA/cm2. In the presence of TCE, chloride, chlorate, and perchlorate were formed that accounted for 79.7 %, 5.53%, and 1.51% of the total chlorine at 60 min. This work illustrates the promise of the Magnéli phase Ti4O7 electrode based electrochemical oxidation technology for degrading per- and polyfluoroalkyl substances (PFASs) and co-contaminants in groundwaters.


2014 ◽  
Vol 2 (33) ◽  
pp. 13492-13497 ◽  
Author(s):  
Gregor Kieslich ◽  
Ulrich Burkhardt ◽  
Christina S. Birkel ◽  
Igor Veremchuk ◽  
Jason E. Douglas ◽  
...  

The thermoelectric properties of the Magnéli phase WO2.90 were investigated, with special attention to how the performance can be altered by changing its microstructure.


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