Superior ethanol sensitivity of crystalline Sn1-xNix(MoO4)(2-x) compounds based on O=Mo=O quasi-conjugated structure

Abstract

Pure Sn(MoO 4 ) 2 nano-sized particles and their Ni-doped samples were synthesized by co-precipitation method at the condition of ice bath, and these samples are amorphous and have no detectable gas response. After being thermally treated for 2 h at 500 °C, the above compound samples are crystalline and have high ethanol sensitivity. The sensor with pure Sn(MoO 4 ) 2 compound achieves a gas response as high as 194–500 ppm ethanol at 280 °C, and its corresponding response and recovery time is about 2 s and 12 s, respectively. Moreover, Ni doping can further improve the ethanol sensitivity of pure Sn(MoO 4 ) 2 compound. Sn 0.9 Ni 0.1 (MoO4) 1.9 compound shows an extremely high gas response of 975 to the same ethanol concentration at 260 °C, and its corresponding response and recovery time is about 1.5 s and 10.5 s, respectively. Possible reasons for the superior ethanol sensitivity were discussed from the crystalline structure and the role of Ni doping. • Sn(MoO 4 ) 2 crystalline nanoparticles and Ni-doped counterparts were prepared. • Pure Sn(MoO 4 ) 2 crystalline nanoparticles has high ethanol sensitivity. • Ni-doping can further improve the ethanol sensitivity of the pure samples. • Various factors and their synergy effects account for the high gas sensitivity.