Sonochemical-driven ultrafast facile synthesis of SnO₂ nanoparticles: Growth mechanism structural electrical and hydrogen gas sensing properties

Synthesis of SnO₂ nanoparticles have been successfully accomplished moderately at lower temperature by facile, rapid, efficient and mild ultrasonic irradiation method. The as-grown SnO₂ nanoparticles are investigated by various characterization techniques in terms of structural, optical, electrical and gas sensing properties. XRD investigation has shown that the SnO₂ nanoparticles materials exhibit single rutile crystal phase with high crystallinity. FESEM studies showed uniform and monodisperse morphology of SnO₂ nanoparticles. The chemical composition of SnO₂ was systematically studied by EDX measurements. Additional confirmation of three Raman shifts (432, 630, 772 cm^-1) indicated the characteristic properties of the rutile phase of the as-grown SnO₂ nanoparticles. The optical properties of SnO₂ nanoparticles were examined by DRS, and the electronic band gap of SnO₂ nanoparticles were around 3.6 eV. Electrical properties of the SnO₂ nanoparticles measured at various temperatures have shown the semiconducting properties. Surface area and pore size of synthesized nanoparticles were analyzed from BET. It has been revealed that SnO₂ nanoparticles have surface area is 47.8574 m²/g and the pore size is 10.5 nm. Moreover, hydrogen gas sensor made of SnO₂ nanoparticles showed good sensitivity and faster response for the hydrogen gas. This method is template-less and surfactant-free which circumvents rigorous reaction work-up for the former removal, reaction temperature and reaction time compared to hydrothermal synthesis and pertinent to many other oxide materials.