Synthesis of Polypyrrole/MoO₃ Hybrid Thin Films and Their Volatile Organic Compound Gas-Sensing Properties

Abstract

Thin films of the intercalated organic-inorganic hybrids (PPy) x MoO 3 (PPy: polypyrrole) have been prepared by an ex-situ intercalation process. The host MoO 3 films were first deposited on LaAlO 3 (LAO) single-crystal substrates by using a CVD method followed by the intercalation of PPy into the MoO 3 films. The preparation of highly b-axis oriented MoO 3 films is crucial to prepare the (PPy) x MoO 3 films. The (PPy) x MoO 3 thin film shows a semiconducting-like transport with an activation energy of 0.21 eV. The (PPy) x MoO 3 thin films show a distinct response to VOCs by increasing their electrical resistivity and exhibit higher sensitivities to polar analytes such as formaldehyde and acetaldehyde, whereas it showed almost no response to toluene and benzene.

Influence of Dodecylbenzene Sulfonic Acid Doping on Structural, Morphological, Electrical and Optical Properties on Polypyrrole/3C-SiC Nanocomposites

“…The band observed at 1004 cm −1 and 676 cm −1 maybe recognized to the out of plane ring deformation and to the N-H vibrations in polymer [13]. The band at 2907 cm , is assigned to C-H stretch (strong), N-H bending vibration of C=C and C-C in the Pyrrole ring, C-N stretch, confirming the Polypyrrole formation [15]. Frequencies and their assignment of DBSA doped PPy-SiC nanocomposite is described in Table 1.…”

Preparation of Polystyrene and Surfactant Co-intercalated MoO3 Nano Hybrids and their VOC Gas Sensing Properties

“…MoO 3 and Na x MoO 3 thin films were prepared as reported in the past work (11) . Polystyrene and surfactant, didodecyldimethylammonium, co-intercalated (PS) x (C 26 H 56 N) y MoO 3 thin films were synthesized by immersing the Na x MoO 3 thin films into the CHCl 3 Powder X-ray diffraction (XRD) data at room temperature were collected on a Rigaku RINT2100V/PC instrument, with a graphite monochromator to produce a Cu K α beam, at 40 kV and 30 mA.…”

“…In our past work, chemical vapour deposition (CVD) was applied to obtain MoO 3 thin film with the b-axis orientation, which is the inorganic host for the organic/MoO 3 thin films (11) (12) . We have investigated the VOC gas sensing properties for (polypyrrole) x MoO 3 ((PPy) x MoO 3 ) (11) and (PANI) x MoO 3 (12) hybrid thin films. These films show a distinct response when they are exposed to formaldehyde or acetaldehyde gas balanced with nitrogen or dry air.…”

Nanostructural design of electrically conductive ceramics and its application in gas sensors

“…32) The gas detection mechanism that we have proposed can be explained as follows. When a polar gas molecule is adsorbed onto the organic layer, the interaction between the gas molecule and the organic layer becomes stronger.…”