Synthesis of conductive ATO nanoparticles

In a typical synthesis, 30 ml of concentrated HNO3 (69 wt%, purists. p.a., Sigma Aldrich, USA) is added to 50 ml deionized water in an open 100 ml PTFE autoclave liner. 2000 mg (16.85 mmol) granulated Sn (≥99.5%, Sigma Aldrich, USA) and 129 mg (0.44 mmol) Sb2O3 powder (≥99.9%, Sigma Aldrich, USA) (molar ratio Sb/Sn = 5/95) is at once added under vigorous stirring, leading to a noticeable NO2 release and the formation of a yellowish colloid. After 10 minutes, the autoclave (HighPreactor BR-100, Berghof, Germany) is sealed, heated to 140°C at 2 K/min, held at 140°C for ten h, and passively cooled down to RT overnight. The resulting bluish powder is separated from the liquid phase by centrifugation, repeatedly washed with deionized water until the washing water reaches a pH of 6, then washed with ethanol once and dried in static air at 70°C overnight. Calcination of dry powders is conducted in a tube furnace (Carbolite, Germany) in a gas flow of 20% O2 (99.999%, Westfalen, Germany) in Ar (99.999%, Westfalen, Germany) at a flow rate of 400 ml/min. Samples are heated to 600°C at 5 K/min, held at 600°C for three h, then passively cooled to RT in the furnace. Calcined samples are ground in a planetary ball mill (Pulverisette 7 Premium Line, Fritsch, Germany). Therefore, 1 g of the sample is suspended in 3 ml isopropanol. The suspension is poured into a 20 ml ZrO2 milling jar containing 10 ZrO2 balls (Ø 10 mm). Milling is conducted at 200 rpm over six cycles of 10 min milling time each and 1 min pause between cycles. The product is then separated from the solvent by centrifugation and dried at 70°C in static air overnight. If you are looking for high quality, high purity, and cost-effective ATO, or if you require the latest price of ATO, please feel free to email contact mis-asia.