Fabrication and gas sensing properties of Au-loaded SnO2 composite nanoparticles for highly sensitive hydrogen detection

Pristine tin dioxide (SnO 2 ) and Au-loaded SnO 2 composite nanoparticles were synthesized by a simple hydrothermal method. The phase structure, composition, and morphology of synthesized Au-loaded SnO 2 composite nanoparticles were comprehensively investigated. Furthermore, the gas sensing performance of the as-prepared pristine and Au-loaded SnO 2 gas sensors toward low concentration of hydrogen (H 2 ) were systematically evaluated. The results indicated that compared to the pristine SnO 2 gas sensor, the Au-loaded SnO 2 composite nanoparticles could not only significantly improve the gas sensing response, but also decrease the optimum working temperature. Moreover, the experimental results showed that the 4.0   at.% Au-loaded SnO 2 gas sensor exhibited the highest response (25) to 100   ppm H 2 at 250   °C, which was about five times higher than that of the pristine one. In addition, it also provided a rapid response/recovery time (1   s/3   s) and a low detection limit (1   ppb). Therefore, Au-loaded SnO 2 composite nanoparticles are more suited for hydrogen detection compared to pristine SnO 2 gas sensor.