Effect of Temperature on the Electrical and Gas Sensing Properties of Polyaniline and Multiwall Carbon Nanotube Doped Polyaniline Composite Thin Films

2011 ◽  
Vol 254 ◽  
pp. 167-170 ◽  
Author(s):  
Subodh Srivastava ◽  
Sumit Kumar ◽  
Vipin Kumar Jain ◽  
Y.K. Vijay

In the present work we have reported the effect of temperature on the gas sensing properties of pure Polyaniline (PANI) and Multiwall carbon nanotube (MWNT) doped PANI composite thin film based chemiresistor type gas sensors for hydrogen gas sensing application. PANI and MWNT doped PANI composite were synthesized by in situ chemical oxidative polymerization of aniline using ammonium persulfate in an acidic medium. The thin sensing film of chemically synthesized PANI and MWNT doped PANI composite were deposited onto finger type Cu-interdigited electrodes using spin cast technique to prepared chemiresistor type gas sensor. The electrical properties of these composite thin films were characterized by I-V measurements as function of temperature. The I-V measurement revealed that conductivity of composite thin films increased as the temperature increased. The changes in resistance of the composite thin film sensor were utilized for detection of hydrogen gas. It was observed that at room temperature, MWNT doped PANI composite sensor shows higher response value and sensitivity with good repeatability in comparison to pure PANI thin film sensor. It was also observed that both PANI and MWNT doped PANI composite thin film based sensors showed unstable behavior as the temperature increased. The surface morphology of these composite thin films has also been characterized by scanning electron microscopy (SEM) measurement.

RSC Advances ◽  
2017 ◽  
Vol 7 (26) ◽  
pp. 15885-15893 ◽  
Author(s):  
Khadija Munawar ◽  
Muhammad Adil Mansoor ◽  
Wan Jefrey Basirun ◽  
Misni Misran ◽  
Nay Ming Huang ◽  
...  

CuO–MnO–2TiO2 composite thin film having a photocurrent density of 2.21 mA cm−2 at +0.7 V has been deposited from a homogeneous mixture of acetates of Cu and Mn and (Ti(O(CH2)3CH3)4) in the presence of trifluoroacetic acid in THF via AACVD at 550 °C.


2015 ◽  
Vol 39 (9) ◽  
pp. 7442-7452 ◽  
Author(s):  
Muhammad Ali Ehsan ◽  
Hamid Khaledi ◽  
Alagarsamy Pandikumar ◽  
Perumal Rameshkumar ◽  
Nay Ming Huang ◽  
...  

ZnTiO3–TiO2 composite thin film electrode has been fabricated by AACVD method and tested for electrochemical nitrite ion detection.


2021 ◽  

<p>Pure and Zr doped ZnO thin films were prepared using SILAR technique. The influence of Zr doping on structural, morphological, optical and gas sensing properties of ZnO has been reported. X-ray diffraction study confirmed the formation of wurtzite structure of ZnO thin film (JCPDS 36-1451) fabricated by SILAR technique and the caluculated crystallites size of pure and doped ZnO were 39 and 36 nm respectively . SEM analysis of thin films has shown a completely different surface morphology. EDAX spetrum cnfirmed the presence of different compositional element in the fabriated thin films. Zr (3 wt%) doped ZnO thin film exhibited the best properties with a good transmittance and it has wide band gap of 3.26 eV. Photoluminescence emissions indicated increase in concentration of oxygen vacancies with introduction of dopant. NH3 vapour sensors were fabricated out of fabricated samples and it was observed that doped samples have significantly high sensing response, good selectivity, fast response and recovery time to ammonia vapoutr at room temperature.</p>


2000 ◽  
Vol 15 (6) ◽  
pp. 1291-1302 ◽  
Author(s):  
W. Zhu ◽  
O. K. Tan ◽  
J. Deng ◽  
J. T. Oh

Ferroelectric(Ba0.67Sr0.33)TixO3 (BST) thin films with x = 0.98, 1.00, 1.02, and 1.04 were prepared by the sol-gel technology, and their thermal, structural, dielectric, and gas sensing properties were systematically characterized. The amorphous (Ba0.67Sr0.33)TixO3 thin film capacitive devices were made on Si substrate to detect hydrogen gas and to study hydrogen-induced interfacial polarization potential.Experimental results showed that the Schottky I–V behavior appears in these Pd/amorphous BST thin film/metal capacitive devices and that enhanced interfacial dipole potentials as large as 4.5 V at 1000 ppm hydrogen gas in air were newly observed, which is about 7 times larger than the best value reported under similar testing conditions. It was clearly shown that the hydrogen-induced interfacial polarization potential is closely correlated with the microstructure of ferroelectric thin films and the enhancement of this interfacial polarization potential is mainly attributed to the high dielectric constant of amorphous ferroelectric thin films. A simple hydrogen interface-blocking model is also presented to explain this interesting phenomenon.


2014 ◽  
Author(s):  
Subodh Srivastava ◽  
S. S. Sharma ◽  
Preetam Sharma ◽  
Vinay Sharma ◽  
Rajveer Singh Rajura ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 478
Author(s):  
Wan Mohd Ebtisyam Mustaqim Mohd Daniyal ◽  
Yap Wing Fen ◽  
Silvan Saleviter ◽  
Narong Chanlek ◽  
Hideki Nakajima ◽  
...  

In this study, X-ray photoelectron spectroscopy (XPS) was used to study chitosan–graphene oxide (chitosan–GO) incorporated with 4-(2-pyridylazo)resorcinol (PAR) and cadmium sulfide quantum dot (CdS QD) composite thin films for the potential optical sensing of cobalt ions (Co2+). From the XPS results, it was confirmed that carbon, oxygen, and nitrogen elements existed on the PAR–chitosan–GO thin film, while for CdS QD–chitosan–GO, the existence of carbon, oxygen, cadmium, nitrogen, and sulfur were confirmed. Further deconvolution of each element using the Gaussian–Lorentzian curve fitting program revealed the sub-peak component of each element and hence the corresponding functional group was identified. Next, investigation using surface plasmon resonance (SPR) optical sensor proved that both chitosan–GO-based thin films were able to detect Co2+ as low as 0.01 ppm for both composite thin films, while the PAR had the higher binding affinity. The interaction of the Co2+ with the thin films was characterized again using XPS to confirm the functional group involved during the reaction. The XPS results proved that primary amino in the PAR–chitosan–GO thin film contributed more important role for the reaction with Co2+, as in agreement with the SPR results.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1348
Author(s):  
Hiroki Nagai ◽  
Naoki Ogawa ◽  
Mitsunobu Sato

Deep-ultraviolet (DUV) light-transparent conductive composite thin films, consisting of dispersed multiwalled carbon nanotubes (MWCNTs) and SiO2 matrix composites, were fabricated on a quartz glass substrate. Transparent and well-adhered amorphous thin films, with a thickness of 220 nm, were obtained by weak ultraviolet (UV) irradiation (4 mW cm−2 at 254 nm) for more than 6 h at 20−40 °C onto the precursor films, which were obtained by spin coating with a mixed solution of MWCNT in water and Si(IV) complex in ethanol. The electrical resistivity of MWCNT/SiO2 composite thin film is 0.7 Ω·cm, and transmittance in the wavelength region from DUV to visible light is higher than 80%. The MWCNT/SiO2 composite thin film showed scratch resistance at pencil hardness of 8H. Importantly, the resistivity of the MWCNT/SiO2 composite thin film was maintained at the original level even after heat treatment at 500 °C for 1 h. It was observed that the heat treatment of the composite thin film improved durability against both aqueous solutions involving a strong acid (HCl) and a strong base (NaOH).


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