Synthesis of Ti4O7 Nanoparticles by Carbothermal Reduction Using Microwave Rapid Heating

Abstract

Abstract:The polymer electrolyte fuel cell (PEFC) is an attractive power generation method from the perspective of environmental protection. Carbon is usually used as a catalyst support in PEFC, but it is oxidized under high electrical potential conditions. Ti 4 O 7 is expected as a new catalyst support because of its high electrical conductivity and chemical resistivity. Though Ti 4 O 7 as a catalyst support must have a high specific surface area for a high performance, it is difficult to synthesize nanostructured Ti 4 O 7 . In this research, Ti 4 O 7 nanoparticles with a size of about 60 nm were synthesized by carbothermal reduction of TiO 2 nanoparticles with polyvinylpyrrolidone (carbon source) using 2.45 GHz microwave irradiation. The experiment condition was at 950 • C for 30 min and the samples synthesized by conventional heating showed a grain growth. The findings of this study suggest that microwave processing can drastically reduce the total processing time for the synthesis of nanostructured Ti 4 O 7 .

Polysulfide Binding to Several Nanoscale Magnéli Phases Synthesized in Carbon for Long‐Life Lithium–Sulfur Battery Cathodes

“…[55] We also examined the cathode after discharging and charging. [41] The Ti phases remain oxides, and TiS 2 or relatedp hases do not form. [31] The TiÀSp hotoemission remains after charging (i.e.,a fter ac omplete charge following 300 cycles), confirming strongP Sa dsorption.…”

“…This suggestst hat sulfur species maintain interaction with several MagnØli phases in the Ti 2 O 2nÀ1 NPs that co-exist within the cathodef or at least 300 cycles. [41] The Ti phases remain oxides, and TiS 2 or relatedp hases do not form.…”

“…[36][37][38] Both investigationsi nvolved the use of pure hydrogen to synthesize oxygen-deficient phases of TiO 2 .P ang et al reported Ti 4 O 7 /S composite loaded on carbon fiber paper as positive electrode [39] and the beginningo fageneral approacht o use the polar surfaces of conductive MagnØli-phaseo xides and other inorganic materials to enhanced surface-mediated redox chemistry fors o-called sulfiphillic materials. [41] Pure metal oxide cathodes are prone to pulverization,a nd cells assembled from these cathodes also require ah igh concentration of electrolyte to realize good performance, which is not appropriate for high gravimetric capacities. [40] Second, organotitanium synthesis impedes the control on the shape of MagnØli-phase NPs as the shapeo f raw TiO 2 is more difficult to control.…”

“…[40] Second, organotitanium synthesis impedes the control on the shape of MagnØli-phase NPs as the shapeo f raw TiO 2 is more difficult to control. [41] Pure metal oxide cathodes are prone to pulverization,a nd cells assembled from these cathodes also require ah igh concentration of electrolyte to realize good performance, which is not appropriate for high gravimetric capacities. [42] These limitations can be alleviated by integrating metal oxide NPs into lightweight conductive carbon matrices and rationally controlling nanoscale MagnØli phases concurrently.…”

Size Control of Ti4O7 Nanoparticles by Carbothermal Reduction Using a Multimode Microwave Furnace

“…In addition to controlling the size of the nanoparticles, it is also necessary to employ simple, practical techniques for the synthesis. In our previous works, Ti 4 O 7 nanoparticles were prepared using microwave irradiation by a carbothermal reduction process, where the device used was a single-mode furnace [25,26]. To scale up the microwave carbothermal process for industry, the process has to be adapted to multimode furnaces.…”