Highly Sensing and Selective Performance Based on Bi-Doped Porous ZnSnO3 Nanospheres for Detection of n-Butanol.

In this study, pure zinc stannate (ZnSnO3) and bismuth (Bi)-doped ZnSnO3 composites (Bi-ZnSnO3) were synthesized via the in situ precipitation method, and their microstructures, morphologies, chemical components, sizes, and specific surface areas were characterized, followed by testing their gas sensing properties. The results revealed that Bi-ZnSnO3 showed superior gas sensing properties to n-butanol gas, with an optimal operating temperature of 300 °C, which was 50 °C lower than that of pure ZnSnO3. At this temperature, moreover, the sensitivity of Bi-ZnSnO3 to n-butanol gas at the concentration of 100 ppm reached as high as 1450.65, which was 35.57 times that (41.01) of ammonia gas, 2.93 times that (495.09) of acetone gas, 6.02 times that (241.05) of methanol gas, 2.54 times that (571.48) of formaldehyde gas, and 2.98 times that (486.58) of ethanol gas. Bi-ZnSnO3 had a highly repeatable performance. The total proportion of oxygen vacancies and chemi-adsorbed oxygen in Bi-ZnSnO3 (4 wt%) was 27.72% to 32.68% higher than that of pure ZnSnO3. Therefore, Bi-ZnSnO3 has considerable potential in detecting n-butanol gas by virtue of its excellent gas-sensing properties.