H2S sensing characteristics of La0.7Pb0.3Fe0.4Ni0.6O3 based nanocrystalline thick film gas sensor

Molybdenum and tungsten oxide based gas sensors for high temperature detection of environmentally hazardous sulfur species

“…Although the volume of the literature is remarkable, most of the works are devoted to semiconducting oxides and the operation temperatures of these sensors have been reported from only room temperature to 300 • C. One of the few papers describing sensing H 2 S at higher temperatures was completed by Dawson et al; they utilized a Cr 2-y Ti y O 3+x sensing composition for a resistive-type sensor design [18] The material demonstrated a p-type characteristic at elevated temperatures (>250 • C) and showed an increase in resistance upon exposure to H 2 S (50 ppm) within a testing range of 250-500 • C. It is the sole paper, at least to our knowledge in literature, that provided temperature desorption curves for both SO 2 and H 2 S. It was seen that H 2 S exhibited two maxima at about 150 • C and 470 • C; however, the loss of SO 2 from the surface occurred at 470 • C. It was concluded that a sensor that operates at 350 • C can be cleaned by heat treatment, and a pre-treatment will increase the sensor response of the sensor [18] Some of the other transition metal oxides demonstrated for H 2 S sensing are as follows: PdO x , WO 3 , MoO 3 , In 2 O 3 , CeO 2 , SnO 2 , TiO 2 , ZnO, CuO, CdO, and various ferrites [10,15,[19][20][21][22][23][24][25][26] A majority of these reports are based on WO 3 compositions [8,10,15,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] In the current work, tungstate and molybdate compositions were investigated as alternative sensing materials to the typical binary compositions for sulfur gas species at higher testing temperatures (≥600 • C). Tungstates and molybdates are known to be wide band gap oxide semiconductors (3-5 eV).…”

Development of wide band gap sensor based on AlNbO4 nanopowder for ethanol

“…The electrical resistance was measured both in the presence and absence of the test gas. The sensor response (S) was calculated using the following equation [12];…”

Metal Oxide Nanoparticles

“…Other complex nanocrystalline oxide based materials such as Gd 0.9 Sr 0.1 CoO 3 [281] and La 0.7 Pb 0.3 Fe 0.4 Ni 0.6 O 3 [282] have also been studied. In the both cases the response of the pure material to CO 2 and O 2 for the former and to H 2 S for the latter, were improved by the addition of Ag or Pd, respectively.…”