Portal de Periódicos da CAPES

Synthesis and Characterization of Mesoporous Indium Tin Oxide Possessing an Electronically Conductive Framework

2002; American Chemical Society; Volume: 124; Issue: 29 Linguagem: Inglês

10.1021/ja0125826

1943-2984

Theo T. Emons, Jianquan Li, Linda F. Nazar,

Supercapacitor Materials and Fabrication

The new mesoporous transparent conducting oxide based on indium-tin-oxide, meso-ITO, has been synthesized by a modified sol-gel method, using CTAB as the surfactant. Critical was the employment of triethanolamine to control the rate of hydrolysis and inhibit deposition of the bulk oxides. Removal of the surfactant by calcination yielded a relatively well-ordered worm-hole motif arrangement of pores visible in the TEM and stable to 400 degrees C. BET measurements revealed no hysteresis in the absorption-desorption isotherm, consistent with a narrow pore-size distribution (between 20 and 40 A depending on the In:Sn ratio); surface areas ranged between 270 and 310 m2/g. This colorless material is the first mesoporous oxide exhibiting substantial framework conductivity, with a conductivity at 25 degrees C of 1.2 x 10-3 S/cm. This distinguishes it from mesoporous mixed-valence transition-metal oxides that exhibit weak hopping semiconductor behavior and much lower conductivity.