Improved gas-sensitive properties for ethanol and acetone in Zn-doped CoTiO3 nanoparticles

Appropriate element doping is an important means to improve gas response. Pure and Zn-doped CoTiO3 nanoparticles were fabricated by a simple sol-gel method and their gas response to ethanol and acetone was studied. Compared with pure CoTiO3 nanoparticles, particle dispersion, specific surface area, oxygen vacancy defects, and gas-sensitive properties of Zn-doped CoTiO3 nanoparticles are optimized and improved. With the increase of Zn doping concentration, the aggregates composed of irregular nanoparticles disperse loosely and the oxygen vacancy defects on the CoTiO3 nanoparticles' surface accordingly increase. The optimum operating temperature of Zn-doped CoTiO3 nanoparticles is slightly reduced from 286 to 260 degrees C. CoTiO3 nanoparticles with Zn doping concentration of 0.05 especially show excellent gas-sensing properties. The sensitivities of Co0.95Zn0.05TiO3 nanoparticles to 50 ppm ethanol and acetone are as high as 125.8 and 143.4, increased to 1.98 and 1.74 times higher than those of pure CoTiO3 nanoparticles. The linear fitting of logarithmic relationship between sensitivity and concentration shows that Zn-doped CoTiO3 can accurately detect low concentration (< 100 ppm) of ethanol and acetone. The improvement of gas response of Zn-doped CoTiO3 nanoparticles is proposed to attribute to the synergistic effect of the agglomeration state of irregular particles and abundant oxygen vacancies on the surface due to Zn doping.