Polyaniline Zinc Oxide Research Articles

Evaluating the electrochemical boost and antimicrobial power of biogenic zinc oxide-polyaniline nanocomposite

Bio-based materials from bark, wood, leaves, and fruits have several uses in nanotechnology. Anthocephalus Cadamba is a biological reducing agent in nanocomposites. The fruit of Anthocephalus Cadamba is used to synthesize ZnO nanoparticles and polyaniline to make a ZnO-PANI nanocomposite. We describe UV–visible, FTIR, XRD, and SEM data to support synthesis. The dielectric constant is highest in the ZnO-PANI nanocomposite compared to pure ZnO nanoparticles. The Nyquist plot semicircular arc confirms temperature-induced conductivity improvement in nanocomposites. Nanocomposites have 1.3 ×10−2 S/m higher conductivity than nanoparticles. The ZnO-PANI nanocomposite has the greatest specific capacitance (Csp) of 1.3 × 10−2. This work suggests that ZnO-PANI nanocomposite electrodes might be useful supercapacitors in energy storage devices with antibacterial properties. XTT assay and biofilm formation assay using CLSM (Confocal laser scanning microscope) indicated that Integration of ZnO-PANI nanocomposites onto biofilm-prone surfaces like medical devices or implants inhibited bacteria adhesion and biofilm growth in antimicrobial investigations.

Polyaniline/ZnO heterostructure-based ammonia sensor self-powered by electrospinning of PTFE-PVDF/MXene piezo-tribo hybrid nanogenerator

Self-powered sensors are receiving increasing attention for their environmental friendliness and energy efficiency. In this work, self-powered polyaniline/zinc oxide (PANI/ZnO) heterostructure-based ammonia (NH3) sensor was driven by polytetrafluoroethylene (PTFE)-polyvinylidene fluoride/Ti3C2Tx (PVDF/MXene) piezo-tribo hybrid nanogenerator (PTNG) at room temperature. PVDF/MXene nanofiber membranes were prepared using electrospinning technology to construct a PTFE-PVDF/MXene PTNG. This enhances the effective contact area and dielectric properties of the composite film, thereby increasing the surface charge density. Additionally, the synergy between the triboelectric and piezoelectric effects significantly improves the output performance of the PTNG, effectively enabling energy harvesting for wearable devices. In addition, ZnO/PANI composite materials with a large specific surface area and high active sites were prepared, and a self-powered ammonia sensor was constructed based on the impedance matching effect. Furthermore, by constructing a PANI/ZnO p-n heterojunction, the number of active sites has been increased, significantly enhancing the sensing performance. The sensor has a minimum detection limit of 0.1 ppm, and at an NH3 concentration of 10 ppm, the response rate reaches 96.1 %. This study provides insights for the development of self-powered gas detection systems and holds significant research and practical value in enhancing the performance of NH3 sensors.

Synthesis of Polyaniline-Zinc Oxide Composites: Assessment of Structural, Morphological, and Electrical Properties

Synthesis of Polyaniline-Zinc Oxide Composites: Assessment of Structural, Morphological, and Electrical Properties

Ion Fluence-Dependent Structural and Electrical Characteristics of Electrochemically Synthesized PANI/ZnO Nano

The electrochemical synthesis and ion irradiation effects of polyaniline/zinc oxide (PANI/ZnO) nanocomposite films on stainless steel substrates were investigated in this study. The structural, morphological and electrical properties of the films were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and current-voltage (I-V) measurements. The results show that the films have a nanofiber network structure with an average diameter of 50-60 nm. The vibrational modes and structural properties of the films are influenced by ion fluence. The electrical conductivity and mobility of the films increase significantly at low fluence (1.0 × 1011 ions/cm2), reaching values of 1.14 × 10-2 S/cm and 3.56 × 10-5 cm2/V-s, respectively. However, at high fluence, electrical properties degrade due to the damage caused by the ion irradiation. This study demonstrates the potential of PANI/ZnO nanocomposite films for applications in the optoelectronic devices and energy storage devices.

Detection of Salmonella Enteritidis in Milk Using Conductometric Immunosensor Coated on Polyaniline/Zinc Oxide Nanocomposite.

The demand for rapid and accurate detection methods for Salmonella Enteritidis necessitates the development of highly sensitive and specific biosensors to ensure proper monitoring of food safety and quality requirements in the food sector and to secure human health. This study focused on development of a polyaniline/zinc oxide (PANI/ZnO) nanocomposite film on a gold electrode conductometric immunosensor for detection of Salmonella Enteritidis. The sensor was modified with monoclonal anti-Salmonella Enteritidis antibodies as biorecognition elements. The fabricated sensor was able to detect and quantify the target pathogen within 30 min and showed a good detection range from 101 to 105 colony-forming units (CFU)/mL for Salmonella Enteritidis and a minimum detection limit of 6.44 CFU/mL in 0.1% peptone water. Additionally, the fabricated sensor showed good selectivity and detection limit toward the target bacterium and successfully determined Salmonella Enteritidis content in ultrahigh heat-treated skim milk samples without pretreatment of the food sample.

On the toxicity behaviour of composite polyaniline-zinc oxide photocatalytic nanoparticles and their surrogate chemicals

The acute toxic effect of home-made polyaniline-zinc oxide (PANI-ZnO) nanocomposite photocatalyst samples was investigated. Toxicity behaviour was compared with that of their surrogates PANI-emeraldine base (PANI-EB), PANI-emeraldine salt (PANI-ES) and zinc oxide (ZnO). The freshwater crustacean Daphnia magna reacted more sensitively to the exposure than the marine photobacterium Vibrio fischeri and thus higher acute toxicity levels were recorded for Daphnia magna. The toxicity response increased with exposure time for both tested organisms. The hydrophobic PANI-EB was non-toxic, whereas ZnO nanoparticles were toxic towards both test organisms and the main reason of the toxicity of the PANI-ZnO composites. The toxicity behaviour changed with ZnO content rather than the PANI-ZnO nanocomposite synthesis type (in-situ polymerization or hybridization method). The acute toxicity also increased when the PANI-ZnO samples were subjected to UV-A (photocatalytic) treatment (conditions:0.25 g/L catalyst; pH=7.0; t = 180 min; I0 =0.5 W/L). A relationship between the photo-induced Zn(II) release and acute toxicity increase after photocatalytic treatment was evident.

PANI-ZnO clad modified multimode optical fiber pH sensor based on EWA

In the present investigation, an intrinsic intensity modulated optical fiber pH sensor is developed and experimentally tested at room temperature. To fabricate the sensor probe, original cladding of multimode fiber was replaced by a pH-sensitive polyaniline-zinc oxide (PANI-ZnO) nanocomposite matrix whose absorbance property and refractive index (RI) are pH dependent. The synthesized PANI, ZnO, and incorporation of ZnO into PANI was confirmed and analyzed by some characterization techniques. It was observed that the ZnO composition into PANI not only enhances the materials's optical activity, porosity and hence sensitivity of the sensor but also boosts the mechanical strength of the coating layer over silica surface. Moreover, high index ZnO material is used to enhance the evanescent field towards the sensing region, which can help in better interaction of light from the outer medium. The pH sensing principle depends upon evanescent wave absorption (EWA) due to swelling/shrinkage of PANI and hence modification in volume and RI of the layer leads to change in transmitted optical power. The average sensitivity of proposed sensor was found to be 2.46 μW/pH for a wide pH range of 2–10 unit. The sensor also possesses excellent stability, fast response time, low hysteresis, good repeatability and durability characteristics. Results suggest that this sensor can be productively utilized in biomedical and chemical sensing applications.

Broad-class volatile organic compounds (VOCs) detection via polyaniline/zinc oxide (PANI/ZnO) composite materials as gas sensor application

Metal-oxide doped conductive polymers have been investigated as sensors in the field of gas-sensing. Recent developments have highlighted the role of intrinsically conductive polymers, that have reportedly offered high surface response towards the detection of volatile organic compounds (VOCs). In this work, we optimize the development of gas-sensors made of Polyaniline/Zinc oxide (PANI/ZnO) composite, capable of detecting a varied class of VOCs such as, ammonia, acetone, formaldehyde, methanol, and ethanol. The conductivity of these sensors is evaluated at room temperature and are investigated until saturation. In addition to the final application, this work also focusses on the synthesis strategies to achieve an ‘optimal’ matrix-to-additive ratio, such that superior chemical response is paralleled with mechanical robustness for PANI based sensors. The PANI/ZnO composites are casted into sensors bearing different additive ratios, via a drop-casting method and the same is evaluated for its formability and mechanical behavior. Physio-chemical characterization was performed using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Energy Dispersive X-ray Analysis (EDX) and we report on an exceptional selectivity for ammonia with an average sensor response of 3496.67 mV by all the sensors, when fabricated using different matrix-additive ratios. This result is superior to what is observed for Pure- PANI sensors that were selective only to methanol and ethanol. The addition of ZnO in the smallest fraction, already offers a broader range of selectivity, e.g., PANI/ZnO 90:10 sensor was selective to formaldehyde as assessed using pattern recognition.

PANI-ZnO/Pt–Ru electrocatalyst for methanol oxidation: Synthesis, characterization, electrocatalytic performance and artificial neural network modeling

In methanol oxidation, fabrication of novel electrocatalysts consisted of a lower loading of precious metals like platinum and ruthenium as well as possessing great electrocatalytic performance is of interest. One approach is to use an appropriate substrate. In this study, Polyaniline-Zinc oxide (PANI-ZnO) nanocomposites were prepared by polymerization method. Then, PANI-ZnO/Pt–Ru electrocatalyst was fabricated using the synthesized nanocomposites as a platinum and ruthenium (Pt–Ru) substrate. Field Emission Scanning Electron Microscopy (FESEM) was applied to study the morphology of the samples, while X-ray diffraction (XRD) analysis and Fourier Transform Infrared Spectroscopy (FTIR) were used to evaluate their phase structure and chemical groups, respectively. Electrochemical behaviors of fabricated PANI-ZnO/Pt–Ru electrocatalyst in the oxidation of methanol were specified via linear sweep voltammetry (LSV), cyclic voltammetry (CV), and chronoamperometry (CA) methods. The current density of PANI-ZnO/Pt–Ru was 91.14 mA/cm2, which was about 15% greater than the current density of Pt/Ru. This reflects the high catalytic performance of the electrocatalyst in the presence of nanocomposites. The electrochemically active surface area of the PANI-ZnO/Pt–Ru and Pt–Ru electrocatalysts are 37.72 m2/g and 21.22 m2/g, respectively. This increase is due to the specific morphology in the structure of nanocomposites. In general, these findings exhibited that the presence of PANI-ZnO support could enhance the catalytic performance and stability of Pt–Ru electrocatalysts. Besides, artificial neural network (ANN) model was used to predict the rate-determining reaction in methanol oxidation at different electrodes and the results indicated the efficiency of the model for forecasting.

The Adsorption Performance of Polyaniline/ZnO Synthesized through a Two-Step Method

Polyaniline/Zinc oxide (PANI/ZnO) were prepared using a two-step method, and the morphology and the structure of PANI/ZnO composites were characterized through a scanning electron microscope (SEM) and X-ray diffraction (XRD). Factors such as the content of ZnO, the adsorption time and the mass of the adsorbent, and the kinetic equation of PANI/ZnO as adsorbents for the adsorption of methyl orange solution were studied. The results showed that the adsorption efficiency of methyl orange by polyaniline with the increase of adsorbent mass firstly increased and then decreased. Among the composites with the same quality, PANI composites with 8% ZnO have a better adsorption effect for methyl orange, and the maximum adsorption ratio can reach 69% with the increase of adsorption time at 0.033 g; With the increase of adsorbent mass, the adsorption efficiency of PANI composites with 8% ZnO increased continuously. When the mass increased from 0.033 g to 0.132 g, the adsorption rate increased from 69% to 93%, and the adsorption of the methyl orange solution by PANI/ZnO composites was more in line with the quasi-second-order kinetic equation.

Conductometric Immunosensor for Escherichia coli O157:H7 Detection Based on Polyaniline/Zinc Oxide (PANI/ZnO) Nanocomposite.

A conductometric immunosensor was developed for the detection of one of the most common foodborne pathogens, Escherichia coli O157:H7 (E. coli O157:H7), by conductometric sensing. The sensor was built based on a polyaniline/zinc oxide (PANI/ZnO) nanocomposite film spin-coated on a gold electrode. Then, it was modified with a monoclonal anti-E. coli O157:H7 antibody as a biorecognition element. The fabricated nanostructured sensor was able to quantify the pathogens under optimal detection conditions, within 30 min, and showed a good detection range from 101 to 104 CFU/mL for E. coli O157:H7 and a minimum detection limit of 4.8 CFU/mL in 0.1% peptone water. The sensor efficiency for detecting bacteria in food matrices was tested in ultra-heat-treated (UHT) skim milk. E. coli O157:H7 was detected at concentrations of 101 to 104 CFU/mL with a minimum detection limit of 13.9 CFU/mL. The novel sensor was simple, fast, highly sensitive with excellent specificity, and it had the potential for rapid sample processing. Moreover, this unique technique for bacterial detection could be applicable for food safety and quality control in the food sector as it offers highly reliable results and is able to quantify the target bacterium.

High photocatalytic performance for hydrogen production under visible light on the hetero-junction Pani-ZnO nanoparticles

The present work is devoted to the preparation of the hetero-junction of Polyaniline-Zinc oxide nanoparticles (Pani-ZnONps) and its photo-electrochemistry to assess its photocatalytic properties for the water reduction into hydrogen. The semiconducting characterization of the Pani-ZnONps synthetized by in situ chemical oxidative polymerization was studied for the hydrogen evolution reaction (HER) upon visible light illumination. The forbidden bands Eg (= 1.64 eV, Pani) and (3.20 eV, ZnONPS) were extracted from the UV–Visible diffuse reflectance data. The Electrochemical Impedance Spectroscopy (EIS) showed the predominance of the intrinsic material with a bulk impedance of 71 kΩ cm2. The semi conductivity was demonstrated by the capacitance measurements with flat band potentials (Efb = - 0.7 and - 0.3 VSCE) and carriers concentrations (NA = 1.77 × 1019 and ND = 4.80 × 1020 cm−3) respectively for Pani and ZnONPS. The energetic diagram of the hetero-junction Pani-ZnONps predicts electrons injection from Pani to ZnONPS in KOH electrolyte. An improvement of 78% for the evolved hydrogen was obtained, compared to Pani alone; a liberation rate of 61.16 μmol g−1 min−1 and a quantum yield of 1.15% were obtained. More interestingly, the photoactivity was fully restored after three consecutive cycles with a zero-deactivation effect, indicating clearly the reusability of the catalyst over several cycles.

Solution-based spin cast-processed O-shaped memory devices

We have studied the current transport mechanism by investigating the hysteresis behavior of current–voltage characteristics obtained by solution-processed spin casting O-shaped memory devices made up with hybrid organic/inorganic nanocomposites of polyaniline–zinc oxide (PANI–ZnO) onto the indium tin oxide (ITO)-coated glass. The nanocomposites are characterized by Raman spectroscopy, FTIR, XRD, FE-SEM, and HR-TEM. The electrical characterization of the nanocomposites showed distinct I–V characteristics with large hysteresis. A hysteresis-type I–V characteristic represents O-shaped memory. The performance of hysteresis behavior remained constant, even after fifty operation cycles. Based on our investigation analysis, a chance of charge transport mechanism occurs, and our data analysis shows that a charge carrier transport mechanism occurs. A normalized differential conductance (NDC) also likely exists. The PANI–ZnO layers controlled the movement of the carriers, and the indium tin oxide–polyaniline–zinc oxide–aluminum (ITO–PANI–ZnO–Al) memory device shows a hysteresis-type current–voltage characteristic. It portrays a specific kind of memory devices with low-cost and low power consumption non-volatile memory applications.

Humidity sensor based on poly(lactic acid)/PANI-ZnO composite electrospun fibers.

The electrospinning technique has been successfully used to prepared micro-fibers of the poly(lactic acid)/polyaniline–zinc oxide (PLA/PANI–ZnO) composite. The polyaniline–zinc oxide (PANI–ZnO) nanocomposites are synthesized by hydrothermal and in situ polymerization methods. X-ray diffraction techniques are used to study the structural properties of the PLA/PANI–ZnO composite fibers and the PANI–ZnO nanocomposite. The average crystallite size of the PANI–ZnO nanocomposite is found to be 36 nm. The morphology and diameter of the composite fibers are analyzed by scanning electron microscopy (SEM). The average fiber diameter of the pure poly(lactic acid) (PLA) fiber is around 2.5 μm and that of the PLA/PANI–ZnO composite fiber is around 1.4 μm. Differential scanning calorimetry (DSC) provides the thermal properties of the PLA/PANI–ZnO composite fibers. The melting temperature (Tm) for the pure PLA is observed at 149.3 °C, and it is shifted to 153.0 °C for the PLA/PANI–ZnO composite fibers. The enhanced thermal properties of the composite fibers are due to the interaction between the polymer and the nanoparticles. The water contact angle measurements probe the surface hydrophilicity of the PLA/PANI–ZnO composite fibers. The role of the PANI–ZnO nanocomposite on the sensing behavior of PLA fibers has also been investigated. The humidity sensing properties of the composite fiber based sensor are studied in the relative humidity (RH) range of 20–90% RH. The experimental results show that the composite fiber exhibited good response (85 s) and recovery (120 s) times. These results indicate that the one-dimensional (1D) fiber structure enhances the humidity sensing properties.

Ag/AgCl sensitized n-type ZnO and p-type PANI composite as an active layer for hybrid solar cell application

Acceptor annealed Zinc oxide (ZnO) based donor polyaniline (PANI) composite was synthesized via in-situ polymerization and sensitized with silver/silver chloride (Ag/AgCl) particles for enhancing the optoelectronic response. The sensitized composite is characterized, and the electron transfer mechanism is explained in detail. The absorbance wavelength enhanced for the sensitized composite is the result of a synergistic combination of annealing and sensitization. Elemental composition revealed the formation of sensitized composite inferred via energy dispersive spectroscopy (EDAX) using high-resolution transmission electron microscopy (HRTEM) and filed-emission scanning electron microscopy (FESEM). Selected area diffraction (SAED) pattern unveiled the coexistence of the amorphous and crystalline phase. The change in dipole moment and polarizability of molecules was evaluated using Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy, respectively. Current-voltage (I–V) characteristics proved annealing of ZnO and sensitization of polyaniline composite with annealed ZnO beneficial for current enhancement, which was further validated via cyclic voltammetry in the form of redox reaction current response.

Remarkable enhancement in sensor ability of polyaniline upon composite formation with ZnO for industrial effluents

Polyaniline emeraldine salt and Polyaniline Zinc Oxide composite are comprehensively studied to compare their sensing ability towards ammonia, acetone, methanol and ethanol. Sensing ability is evaluated through thermodynamic, geometric and electronic parameters. A number of orientations are evaluated in search for the lowest energy structure. The comparison of thermodynamic, geometric and electronic parameters of simple and composite sensors confirmed that composite sensor shows better sensing ability than simple PANI. Composite formation between polyaniline and zinc oxide is a thermodynamically feasible process with interaction energy of −42.8 kcal/mol. Both sensor shows highest interaction energy for ethanol among four analytes. Composite sensor shows almost twice the interaction with ethanol, methanol and acetone while 1.5 times the interaction energy for ammonia. The results of run simulations and subsequent calculations showed that in composite sensors, zinc oxide not only enhances the binding power of conducting polymer with analytes but also interacts directly with analytes. Strong hydrogen bonding as well as weak dispersion forces of attraction are responsible for the stability of composite and all complexes, as revealed by non-covalent interaction (NCI) studies. Acetone shows a different behaviour in composite sensor complex than other analytes.

PANI-ZnO Cladding-Modified Optical Fiber Biosensor for Urea Sensing Based on Evanescent Wave Absorption

In present investigation, we demonstrated a simple, rapid and highly sensitive cladding modified optical fiber urea sensor based on evanescent wave absorption (EWA) technique. Cladding modification was exploited over 2 cm unclad portion of optical fiber using polyaniline-zinc oxide (PANI-ZnO) matrix and enzyme-Urease (Urs) cross-linked on it via glutarldehyde as a cross-linking agent. PANI-ZnO matrix was characterized by X-ray diffraction, scanning electron microscopy, ultraviolet-visible and Fourier transforms infrared spectroscopy to explore the various properties. The developed sensor shows the linear response in the range 10 nM - 1M towards urea concentration in form of absorption spectra at wavelength ~ 250 nm with specific selectivity. Under the proper condition (store at temperature 40 C after the each measurement) shows 40 days stability without any decrement in intensity of absorption spectrum. Thus, the developed sensor is highly sensitive, stable and specific selective with 10 nM lower detection limit of urea concentration.

Low-dose gamma irradiation effect on structural and optical properties of PANI–ZnO composite thin films

The effects of different low doses of gamma irradiation on polyaniline-zinc oxide composite thin films were studied. The structural and optical properties of the sample were investigated using X-ray diffraction, ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy and photoluminescence spectroscopy. The variation in the structural and optical properties shown in this analysis will be helpful in correlating the properties with low-dose radiation dosimetry.

Structural, optical and impedance spectroscopy study of thin film of polyaniline (PANI/ZnO) nanocomposite

Modern organic electronic and power electronic devices gained attention due their superior performance and efficiency with reduced cost. While nanocomposites of these organic semiconductors have high potential to further enhance these properties. In this work, thin films of zinc oxide-polyaniline (ZnO-PANI) nanocomposite with different compositions of ZnO (50, 60 and 70 wt%) are deposited by spin coater onto the surface of p-Si. The phase identification of the samples is identified through x-ray diffraction analysis. Pure ZnO showed wurtzite crystalline while PANI and nanocomposites of ZnO-PANI showed amorphous structure. The optical absorption band gap was evaluated from Ultraviolet–visible spectroscopy absorption studies and band gaps were calculated from Tauc’s plots. The Ultraviolet–visible spectroscopy showed that by increasing ZnO content in the nanocomposite, the band gap increases from 3.25 eV to 3.3 eV and 3.4 eV for 50–50, 60–40 and 70–30 wt% respectively. The AC electrical properties of the nanocomposites were studied by using impedance spectroscopy. The parameters extracted from the impedance plots and conductivity values showed that 50–50 wt% is more conductive while that of 70%–30% wt is more resistive.

Controlling the Growth of Zinc Oxide/ Polyaniline Nanocomposites on Platinum-Coated Substrate for Possible Solar Cell Applications

We report on the growth of zinc oxide/polyaniline (ZnO/PANI) nanocomposites deposited on platinum (Pt)–coated glass substrate via chemical bath deposition and dip–casting technique is reported. Scanning electron micrographs of the nanocomposites revealed that etching of ZnO nanorods takes place during growth which turn into plate–like and distorted nanostructures. We found out that increasing the concentration of NH4OH triggered increase in nanostructure diameter. The surface morphology of nanocomposites significantly changed as the molar concentration of NH4OH precursor varies. Fast fourier transform infrared spectroscopy results showed the interaction of ZnO and PANI by observing the shift of peaks to the higher wavenumbers. The measured optical band gap of the nanocomposites are in good aggreement with the reported values. This result indicates that the grown ZnO/PANI nanocomposites is a good material for solar cell device.