Electrical characterization of V2O5/POMA deposited by casting technique

Conductive polymers derivates, such as poly-o-methoxyaniline (POMA), have been broadly using in different applications due to their similar characteristic of polyaniline. POMA can intercalate into V₂O₅ matrix to improve their structural and electrical properties, and thin films of V₂O₅/POMA can be deposited by different techniques to extender their technological applications after intercalation reactions. V₂O₅ was prepared by sol-gel route. POMA was polymerized from its monomer, o-methoxyaniline, by intercalation reaction into the V₂O₅ matrix. After intercalation reaction, it was possible to note that the structure of the inorganic and organic materials was preserved from the results of DRX, FTIR and SEM. The use of deposition technique by casting for application as component in ammonia sensor, indicated that the parameter as resistance, interface effects and conductivity slightly change with the deposition technique compared with layer by layer deposition. A good theoretical–experimental fitting was observed between the Z′ curves and between the Z’’ curves, according to the theoretical model proposed. In both components, the numerator is much higher than the denominator, so we can infer that the real component (Z′) is approximately proportional to the bulk resistor (R) and that the imaginary component of complex impedance (Z'´) is approximately proportional to the bulk resistor squared (R2). Finally, these results indicated that the R is mostly responsible for the ammonia gas sensitivity obtained by the Z′ measurements and indicate also that R2 is associated with the ammonia gas sensitivity obtained from the Z'´ measurements. Therefore, in the presence of ammonia gas, the film presented a sensitivity in both real and imaginary components of CI with a good reliability confirmed by the theoretical Cole–Cole model.

Audience take-away:

In generally, the sensor can be used form ammonia gas detection.
Sensitivity component can be used possibility a low-cost device.
The device can be easy to handle.