Strategies to improve the electrical conductivity of nanoparticle-based antimony-doped tin oxide aerogels

Abstract

We present different strategies to improve the electrical conductivity of antimony-doped tin oxide aerogels assembled from preformed nanosized building blocks. By adjusting the annealing atmosphere and temperature conditions, additional UV treatment to remove surface organics prior to annealing and by tuning the antimony content of the nanoparticles, different strategies are employed to influence the properties of the supercritically dried aerogels before and after gelation. In the framework of this study, also the formation of pure SnO 2 particlebased aerogels could be achieved. Furthermore, we present an experimental setup for analyzing the electrical conductivity of porous and fragile aerogel monoliths based on a four-point probe. While the annealing atmosphere does not significantly affect the resistivity, UV treatment leads to a resistivity decrease in around 50 %. It is found that the resistivity of the samples can be tuned by altering the antimony content, offering very low-resistivity levels down to 4.5 X cm, while the surface areas remained high without significant crystal growth for the doped samples.

Modern Inorganic Aerogels

“…BaTiO 3 is an attractive material due to its superior piezo-, pyro-, and ferroelectric properties.F urthermore,t hey extended their thermally induced gelation approach to antimony-doped tin oxide aerogels. [147,148] Thee lectrical conductivity of the final gels can be significantly improved by adjusting the antimony content and applying postsynthetic treatments such as annealing and UV curing. Electrically conductive oxide aerogels are very promising materials for applications in electrocatalysis and as battery,s olar-a nd fuel-cell materials.…”

Moderne Anorganische Aerogele

“…[146] Zuerst wurde dabei ein stabiles Sol der Partikel in Ethanol generiert, das durch die mittels Wasserzugabe hervorgerufene ¾nderung der Lçsungsmittelpolaritätd estabilisiert werden Niederberger et al konnten ihren thermisch induzierten Gelbildungsansatz außerdem auf Antimon-dotierte Oxidaerogele ausweiten. [147,148] Die elektrische Leitfähigkeit der fertigen Gele kann durch die Anpassung des Antimongehaltes und postsynthetische Behandlungen wie Te mpern und UV-Härtung signifikant verbessert werden. Elektrisch leitfähige Oxidaerogele sind vielversprechende Materialien fürdie Anwendung in der Elektrokatalyse sowie als Batterie-, Solarzellen-und Brennstoffzellenmaterialien.…”

Conducting ITO Nanoparticle-Based Aerogels—Nonaqueous One-Pot Synthesis vs. Particle Assembly Routes

“…One approach that has been extensively applied for the fabrication of aerogels of diverse metal oxides in recent years is the utilization of crystalline nanoparticles as pre-formed building blocks, which are arranged into a gel via induced coagulation, followed by CPD [ 14 , 15 , 21 , 22 , 23 ]. High crystallinity and purity, a narrow size distribution and good dispersibility in solvents are essential properties of the nanoparticles to achieve highly porous, homogeneous and functional aerogels [ 15 , 22 ]. A proven approach to prepare ITO nanoparticles with such properties is nonaqueous sol–gel synthesis [ 24 ], which offers relatively simple reaction parameters and high yields and is also suitable for scaling up [ 25 ].…”