Synthesis of Ti₄O₇ nanoparticles by carbothermal reduction using microwave rapid heating

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. Ti₄O₇ is expected as a new catalyst support because of its high electrical conductivity and chemical resistivity. Though Ti₄O₇ as a catalyst support must have a high specific surface area for a high performance, it is difficult to synthesize nanostructured Ti₄O₇. In this research, Ti₄O₇ nanoparticles with a size of about 60 nm were synthesized by carbothermal reduction of TiO₂ 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 Ti₄O₇.