Synthesis and characterization of ATO nanoparticles

We aim to produce ATO nanoparticles suitable for electrode preparation, i.e., possessing an adequate electrical conductivity of ≥ 10−1 S/cm combined with the highest possible surface area to enable high capacities, moderate agglomerate size of ≤ 20 μm suitable for the fabrication of smooth electrode coatings, and no contamination by organic residues or chloride which likely would compromise cell performance. To pursue this goal, we apply a hydrothermal synthesis of ATO nanoparticles from chlorine-free precursors using a modified procedure first reported by Zhang and Gao, followed by additional calcination and milling steps. An Sb-doping level of 5 mol% is chosen based on both theoretical and experimental data in the literature: Doping levels of 2–7 mol% Sb should lead to degenerate semiconductors with metallic properties ([43] and sources therein], and ATO nanoparticles with doping levels of 4–10 mol% Sb have been reported to give optimum electrical conductivity. Further, a high Sb5+/Sb3+ ratio and low Sb surface segregation are required to create n-type conductivity. X-ray diffraction patterns of as-synthesized, calcined, and ball-milled ATO samples have been recorded to provide detailed information on the crystal phases and the degree of crystallinity of the materials. The diffraction patterns of all measured samples are in excellent agreement with the cassiterite structure of antimony-doped tin oxide with a chemical composition of Sn0.938Sb0.062O1.88. This corresponds well to our target Sb doping level of 5 mol%, thus confirming the successful doping of the host lattice during the hydrothermal synthesis and the absence of any phase separation during post-synthetic treatments. The as-synthesized sample consists of crystalline domains of ∼5 nm ∅m (calculated from the FWHM of the reflection at 12° 2θ). The XRD-derived crystallite size increases to ∼13 nm ∅m upon calcination and remains unchanged during ball milling. Electrical conductivity measurements, BET, and SLS further analyze all ATO samples to investigate the decisive properties for electrode preparation. 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.