Nanoscale Pd catalysts decorated WO3–SnO2 heterojunction nanotubes for highly sensitive and selective acetone sensing

Ultrasensitive and low detection limit of acetone gas sensor based on ZnO/SnO2 thick films

“…12 On the indexing symbol, except that the peaks belong to pure ZnO, all the remaining diffraction peaks could be indexed to SnO 2 (JCPDS le no. 41-1445) 13 with rutile structure. No other diffraction peaks of impurities such as ZnSnO x could be identied in the patterns, indicating high purity of the ZnO/ SnO 2 composites.…”

Inorganic-Diverse Nanostructured Materials for Volatile Organic Compound Sensing

“…In this track, functionalized/sensitized/assembled/decorated nanotubes (NTs) and multi-walled carbon nanotubes (MWCNTs) were reported by many research groups towards acetone sensing. Pd/Pt functionalized SnO 2 NTs, PdO@ZnO−SnO 2 NTs, α-Fe 2 O 3 NRds-MWCNTs, Co 3 O 4 —MWCNTs, Pt-CuFe 2 O 4 NTs, Pd@WO 3 –SnO 2 NTs, and ZnO-Decorated In/Ga Oxide NTs (synthesized by hydrothermal, encapsulation, electrospinning, and soaking) were reported for exceptional acetone detection at various operating temperatures (225–400 °C) [ 88 , 89 , 90 , 91 , 92 , 93 , 94 ]. These decoration of certain catalytic substrates may enhance acetone selectivity by varying the operating temperature.…”

“…For instance, the sensitivity of Pd@WO 3 –SnO 2 NTs [ 93 ] to acetone was enhanced by multiple heterojunctions formation (W O3 –SnO 2 n–n junctions, PdO–SnO 2 , and PdO–WO 3 p-n junctions) and by the sensitization effect of Pd nanocatalyst. Doped SnO 2 nanobelts were employed as sensor materials for the discrimination of acetone with LODs down to sub-ppm level [ 95 , 96 ].…”

Breakthroughs in the Design of Novel Carbon-Based Metal Oxides Nanocomposites for VOCs Gas Sensing

“…Concerning the former, the sensing mechanism is based on the conductivity change of a nanostructured sensor film as a function of the concentration of reducing/oxidizing gases present. Specifically, chemoresistors are mainly based on the adoption of metal oxide semiconductor (MOS) materials, among which SnO 2 [ 28 , 29 , 30 ], ZnO [ 31 , 32 ], WO 3 [ 9 , 33 ] and TiO 2 [ 34 , 35 ] have been widely exploited. Nevertheless, although they are sensitive to many gases and VOCs, to date, they have not reached the required low concentration sensitivities for an application such as breath analysis.…”