A Novel Trace-Level Ammonia Gas Sensing Based on Flexible PAni-CoFe2O4 Nanocomposite Film at Room Temperature

Abstract

In this study, we developed a new chemi-resistive, flexible and selective ammonia (NH3) gas sensor. The sensor was prepared by depositing thin film of polyaniline-cobalt ferrite (PAni-CoFe2O4) nanocomposite on flexible polyethylene terephthalate (PET) through an in situ chemical oxidative polymerization method. The prepared PAni-CoFe2O4 nanocomposite and flexible PET-PAni-CoFe2O4 sensor were evaluated for their thermal stability, surface morphology and materials composition. The response to NH3 gas of the developed sensor was examined thoroughly in the range of 1–50 ppm at room temperature. The sensor with 50 wt% CoFe2O4 NPs content showed an optimum selectivity to NH3 molecules, with a 118.3% response towards 50 ppm in 24.3 s response time. Furthermore, the sensor showed good reproducibility, ultra-low detection limit (25 ppb) and excellent flexibility. In addition, the relative humidity effect on the sensor performance was investigated. Consequently, the flexible PET-PAni-CoFe2O4 sensor is a promising candidate for trace-level on-site sensing of NH3 in wearable electronic or portable devices.

Novel Hybrid Nanomaterials Based on Poly-N-Phenylanthranilic Acid and Magnetic Nanoparticles with Enhanced Saturation Magnetization

“…Nanocomposite magnetic materials based on polyconjugated polymers are new generation materials with physical and chemical properties required for modern technologies [ 1 , 2 , 3 , 4 , 5 ]. These magnetic nanocomposites can find potential application as hybrid electrocatalysts [ 6 , 7 ], as cathode materials for rechargeable batteries and fuel cells [ 8 , 9 , 10 ], as active materials in solar cells [ 11 , 12 , 13 ] and supercapacitors [ 14 , 15 , 16 , 17 , 18 ], for the remediation of water resources [ 19 , 20 , 21 , 22 , 23 , 24 ], ion-exchange materials [ 25 , 26 , 27 ], ion-specific electrodes [ 28 , 29 , 30 , 31 ], to produce sensors [ 32 , 33 , 34 , 35 , 36 ], as anticorrosive coatings [ 37 , 38 , 39 , 40 ], as electromagnetic radiation absorbing materials [ 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , …”

“…Progress in the creation of novel multifunctional magnetic nanomaterials is due to the development of new synthesis methods for nanostructures. The most common method of obtaining hybrid magnetic nanocomposites is oxidative polymerization of monomers (aniline [ 8 , 9 , 25 , 29 , 32 , 51 , 55 , 56 ], pyrrole [ 28 , 40 , 44 , 57 ] and thiophene [ 23 ]) in a reaction medium containing prefabricated magnetic nanoparticles (Fe 3 O 4 [ 25 , 28 , 29 , 42 , 55 , 58 ], γ -Fe 2 O 3 [ 32 , 43 ], α -Fe 2 O 3 [ 37 ], Co 3 O 4 [ 8 , 9 , 38 , 50 ] and CoFe 2 O 4 [ 33 , 59 ]). One of the ways to prevent the metal nanoparticles aggregation is their stabilization in a polymer matrix during synthesis.…”

The Room Temperature Highly Sensitive Ammonia Gas Sensor Based on Polyaniline and Nitrogen-Doped Graphene Quantum Dot-Coated Hollow Indium Oxide Nanofiber Composite

“…Among ICPs, polyaniline (PANI) is extensively employed for sensing applications due to its easy synthesis, exceptional doping/de-doping chemical reaction, high conductivity, outstanding environmental stability, and excellent responsivity to NH 3 [10]. The incorporation of n-type metal oxide semiconductors, such as In 2 O 3 , SnO 2 , CeO 2 , CoFe 2 O 4 , or carbon-based materials into ICPs can improve the sensing performances of fabricated nanocomposites [11][12][13][14][15][16][17][18]. Xue et al reported that a PANI/carbon nanotube (CNT) composite showed enhanced sensing performance and stability at room temperature as compared to that of pure PANI [12].…”

“…Saleh et al prepared an ammonia gas sensor by depositing a PANI/CeFe 2 O 4 nanocomposite on flexible PET film. Their results showed excellent ammonia gas-sensing performance in the range of 1-50 ppm at room temperature [17]. Indium trioxide (In 2 O 3 ), with high optical transparency and electrical conductivity, is widely used in liquid crystal displays and sensors [18].…”

Capacitive and Conductometric Type Dual-Mode Relative Humidity Sensor Based on 5,10,15,20-tetra Phenyl Porphyrinato Nickel (II) (TPPNi)

“…Recently, conducting polymers based robust and ultra-sensitive sensors of biologically active compounds have been developed for their potential applications in biomedical diagnostics, the food and beverage industry, and environmental analysis [12,13]. Similarly, gas and volatile organic compound (VOC) sensors based on semiconducting metal oxides are also important for various safety and environmental control issues [14][15][16][17]. Likewise, the πconjugated organic semiconductors (consisting of oligomeric/polymeric chain molecules) are a diverse set of materials that have been recently studied to develop cost-effective humidity sensors with superior sensitivity, reproducibility in response, and widespread bandwidth.…”