The various gas sensors were designed for detection of different gases in the air using different oxides and impurities [1-3]. For example the manufacturing of ammonia sensors on the basis of CuxS-micro-porous-Si structure includes manufacture of micro-porous silicon, drawing on it of SiO2 isolating layer, and then the CuxS layer [4, 5]. The special equipment for all these processes is needed. More usable method for sensor production is so-called soft chemistry or sol–gel synthesis [6, 7].
International Letters of Chemistry, Physics and Astronomy (Volume 50)
V. Bondarenka et al., "Xerogels of Ammonium Polyvanadatomolybdate as Starting Material for Ammonia Gas Sensors", International Letters of Chemistry, Physics and Astronomy, Vol. 50, pp. 71-79, 2015