Effect of Au nanoparticles on the gas sensitivity of nanosized SnO2

The effect of the nanosized gold state on the adsorption-sensitive properties of tin dioxide under the detection of CO, CH4 and C2H5OH vapours has been studied. Different techniques that allow obtaining gold particles with the average size ranging from 1.9 +/- 0.1 nm to 3.5 +/- 0.5 nm were applied. The structural features and the surface state of SnO2 and SnO2-Au materials have been studied by using SEM, TEM, XPS, FTIR and UV-Vis spectroscopy. It has been found that an increase in the sensor response to CO, CH4 and C2H5OH vapours is achieved by adding gold in the form of colloid particles with the size range of 1.9-3.5 nm to SnO2 center dot nH(2)O sol. The SnO2-Au layers with the larger particles (3.5 nm) demonstrate the highest response to C2H5OH while SnO2-Au (1.9 nm) composite is the most sensitive to CO and CH4. It has been shown that a selective detection of CH4 and CO in gas mixtures is possible by adjusting the voltage to be applied to SnO2-Au (1.9 nm) sensor. The enhanced sensitivity of the sensor to methane is caused by the nanosized state of both SnO2 and Au components as well as by the modifying effect of sulphur-containing stabilizer of Au particles.

Automated summary

The study investigated the influence of nanosized gold state on the adsorption-sensitive properties of tin dioxide under CO, CH4, and C2H5OH vapor detection. It was found that adding gold colloidal particles with sizes ranging from 1.9-3.5 nm can enhance sensor response, with different sensitivities observed for different gases in SnO2-Au composite materials.