Surfactant-controlled aqueous synthesis of SnO_2 nanoparticles via the hydrothermal and conventional heating methods

Tin oxide nanoplates and nanoballs were fabricated using a cationic surfactant of cetyltrimethylammonium bromide (CTABr) as an organic supramolecular template and tin(IV) chloride as an inorganic precursor via the hydrothermal and conventional heating methods. Urea, which decomposes to ammonium and hydroxide ions during hydrolysis, was used as the source of slow homogeneous precipitation of Sn^4+ with OH^− to control the particle size. The influence of different reaction parameters (time, temperature, and ratio of Sn^4+ to CTABr) on particle sizes, particle distribution, and morphology was investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. XRD data showed that the size of the SnO2 nanoparticles decreased with increasing reaction time using the conventional heating method, while no significant change was observed with the hydrothermal method. Nanoplates with average sizes of 9.36 nm and nanoballs up to 4.51 nm were prepared using different ratios of Sn+4 to CTABr at different temperatures and reaction times by the hydrothermal and conventional heating methods, respectively. Elimination of surfactant from tin-surfactant composites by calcination yielded a porous tin oxide nanostructure.