Polypyrrole Nanocomposites Research Articles

Design and development of low‐weight and high‐strength electromagnetic shielding nanocomposite in a microwave frequency range

AbstractIn this novel work, we fabricated the multiwalled carbon nanotubes (MWCNTs)/polypyrrole (PPy) nanocomposite by employing the novel ultrasonic dual mixing (UDM) method. Subsequently, the atomistics and structural characterizations of the fabricated MWCNT/PPy nanocomposite (PM) were performed using SEM, Raman, and XRD. Furthermore, we experimentally evaluated the mechanical properties of the fabricated PM by reinforcing the PPy matrix with MWCNTs at different wt.%. The experimental study of PM shows that the mechanical properties depend upon the amount and dispersion quality of MWCNTs in the PPy matrix. In order to validate the experimental outcomes, the conservative fully coupled finite element (FE) models were developed using the ANSYS Workbench and novel FEAST software. The electromagnetic interference (EMI) shielding effectiveness (SE) of developed PM was also calculated at different thicknesses of PM by taking the effect of SE due to absorption (SEA) and SE reflection (SER) in the microwave frequency range of the C‐band (5.37–8.2 GHz) into consideration. The total SE (SET), the cumulative sum of SEA and SER, is the strong function of the thickness of the PM. Additionally, our study's outcomes reveal that as the thickness of the PM increased, the SET also increased by dominating the SEA rather than the SER. The SET value of 75 dB was observed for a sample with a thickness of 3 mm, indicating a high level of shielding. Thus, material becomes a highly attractive option for achieving high‐performance EMI SE in the C‐band for satellite communications, Wi‐Fi devices, weather radar systems, surveillance, and cordless telephones. A complex permittivity and permeability were also studied using the Nicolson–Ross–Weir (NRW) method to understand the mechanism behind the EMI SE.Highlights Nanocomposite fabricated using the novel ultrasonic dual mixing method. FE models were developed to validate experimental results. The EC and EMI SE are improved with the increase in the sample thickness. Absorption, rather than reflection, dominated the shielding mechanism. SE was observed dB with good mechanical properties.

Enhancing electromagnetic interference mitigation: A comprehensive study on the synthesis and shielding capabilities of polypyrrole/cobalt ferrite nanocomposites

In a society increasingly infiltrated by digital and networking technologies, designing electromagnetic interference (EMI) shielding materials is critical for safeguarding sensitive electronic equipment and ensuring the smooth functioning of essential communication networks. This study focuses on the optimization of the properties of cobalt ferrite (CoFe2O4)/polypyrrole (PPy) nanocomposites made by in-situ polymerization used for electromagnetic (EM) shielding based on their magnetic and dielectric losses. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and vector network analyzer (VNA) were employed to study the materials' physical and chemical characteristics. The findings demonstrate that the magnetic and electric properties of the materials composed of CoFe2O4 and PPy are substantially altered by the integration of CoFe2O4 and PPy. Adding PPy to CoFe2O4 reduces the real and imaginary parts of magnetic permeability, and the conductivity, dielectric constant, and dielectric loss are increased. These effects are advantageous for EM shielding applications. The high electromagnetic shielding performance mainly results from the enhanced interfacial polarization induced by interface region among CoFe2O4 and PPy molecules. The influence of the PPy matrix in altering the dielectric and magnetic loss factors (tanδE and tanδM) of the embedded ferrite particles is pronounced. Although CoFe2O4 shows excellent attenuation characteristics, it cannot optimally match impedance with free space, particularly at higher frequencies. In addition, material thickness and shielding efficiency adjust the reflection loss (RL) performance. The prepared composites can attenuate more than 95 % of the incident electromagnetic waves. This study emphasizes the benefits of employing composite materials in EMI shielding designs and the combined advantages of conductive and magnetic materials.

New spacious SrWO4/PEDOT-PPy nanohybrids and their electrochemical and photocatalytic activities.

A novel SrWO4-poly(3,4-ethylene dioxythiophene) (PEDOT)-polypyrrole (PPy) nanocomposite was synthesized via chemically oxidative polymerization and considered by using numerous method of the techniques. The resulting SrWO4/PEDOT-PPy nanocomposite demonstrated remarkable electrochemical sensing capabilities for sulfadiazine (SFA). As a modified glassy carbon electrode (SrWO4/PEDOT-PPy/GCE) revealed for superior catalytic activity in the electrochemical oxidation of sulfadiazine, enabling sensitive detection with quantification and detection limits of 1.0936 × 10-9M µA-1 and 2.2104 × 10-9M µA-1, respectively. This technique effectively determined SFA content in real samples. Additionally, SrWO4/PEDOT-PPy demonstrated extraordinary photocatalytic ability, achieving a Methylene Blue (MB) degradation rate of up to 99.1% under halogen light irradiation within 80min. Hybrid photocatalyst has exhibited to strong reusability and photocatalytic stability under frequent light exposure. A contrivance for the photocatalytic deprivation of MB by SrWO4/PEDOT-PPy is proposed. These results underscore the crucial role of SrWO4/PEDOT-PPy in practical environmental remediation analysis. The fluorescence investigations have betrothed to terephthalic acid radical formations of SrWO4/PEDOT-PPy hybrids, which were modulated by different approaches, and its mainly driven for higher illumination aptitudes. Meanwhile, this was more supporting for physio-chemical properties of the phenomenon, at this consequential with significantly well improved to the photocatalytic performances. Because of this, SrWO4/PEDOT-PPy hybrid materials were comprehended to deliver excellent kinetics, and better recyclable activities.

Coral reefs‐like shape AgI/polypyrrole nanocomposite through the intercalation of iodide ions in the network for optoelectronic applications

AbstractA promising optoelectronic device for light sensing in both the UV and Vis regions is fabricated. This device consists of a nanocomposite resembling coral reefs, termed AgI/polypyrrole‐iodide (AgI/Ppy‐I). The resulting nanocomposite exhibits a hierarchical structure wherein larger particles, comprising smaller particles ~45 nm and an optical bandgap measuring 2.4 eV, form a coral reef‐like morphology. The sensitivity estimation of this constructed optoelectronic device relies on evaluating the current density (Jph) values. Under illumination, a remarkable augmentation in current density (Jph = 0.46 mA cm−2) with a promising value compared to the dark condition's 0.12 mA cm−2. The optical characteristics of this nanocomposite make it highly conducive to efficient UV–Vis light sensing. The values of D (detectivity), reflecting the device's sensitivity, are notably high at 4 × 108 and 3.82 × 108 Jones in the UV and Vis regions, correspondingly. The potential of this photodetector is reinforced by the computed R‐values, which denote the device's responsivity. With values of 1.8 and 1.72 mA W−1 across these two optical regions, correspondingly, it showcases the nanocomposite's effectiveness in transforming incident light into electrical current. Moreover, the appeal of this photodetector extends beyond its performance characteristics. Its cost‐effectiveness, eco‐friendliness, straightforward preparation methodology, scalability for mass production, and high stability collectively. The versatility of this material, coupled with its advantageous attributes, opens avenues for its widespread application, catering to the diverse needs of industries and contributing to the accessibility of efficient optoelectronic devices for a broader audience.

Synthesis of PPy-MnO2 Nanocomposite for Utilization in Supercapacitor Applications

Polypyrrole (PPy) nanocomposites were prepared using chemical oxidation and were combined with manganese oxide (MnO2) nanoparticles. The PPY-MnO2 nanocomposite was synthesized by integrating PPy nanofibers with varying volume ratio percentages of MnO2 dopant (10, 30, and 50% vol. ratio). The structural features of the PPy and PPy-MnO2 nanocomposite were investigated using X-ray diffraction (XRD). Fourier transfor infrared (FTIR) spectroscopy was used to demonstrate the molecular structures of primary materials and the final product of PPy, MnO2, and PPy- MnO2 nanocomposites. Field Emission Scanning Electron Microscopy (FESEM) showed that the morphology of PPy consisted of a network of nanofibers. Increasing the volume ratios of manganese oxide added to the PPY nanofiber led to the increase of manganese oxide nanoparticles on the surface of the PPY nanofiber network. This resulted in a noticeable alteration in the structure of the nanocomposite. It has been observed that the nanocomposites demonstrate a significant level of pseudocapacitive activity. The highest capacitance of 236 F/g was observed when pure PPy was doped with 30% MnO2 compared to 125 F/g of the pure PPy.

Optical, thermal, and electrical characteristics of cashew gum/Polypyrrole/zinc oxide nanocomposites for next‐gen optoelectronics

AbstractIn this electronic era, there is a demand to switch from conventional polymers to conducting biopolymers. We developed conducting biopolymer nanocomposites of cashew gum (CG) and polypyrrole (PPy) with zinc oxide (ZnO) nanofillers [CG/PPy/ZnO] via in‐situ oxidative polymerization using a sustainable solvent. These nanocomposites were characterized using Fourier‐transform infrared spectroscopy (FTIR), UV–visible spectroscopy, field emission scanning electron microscope (FE‐SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The FTIR signal at 855 cm−1 confirms the successful inclusion of ZnO nanofillers into the biopolymer. UV–vis absorption of the blend nanocomposite increases with the nanoparticle doses. Among the various blend nanocomposites, the least bandgap energy was observed for 7 wt% ZnO loading. FE‐SEM revealed homogeneous dispersion of ZnO nanofillers in the CG/PPy blend at 7 wt% ZnO. TGA and DSC demonstrated that the CG/PPy/ZnO nanocomposites have better thermal stability and glass transition temperature than the pure polymer blend, indicating enhanced thermal properties. The CG/PPy/7 wt% ZnO showed the highest conductivity, 4.62 times greater than the pristine blend at 100 Hz. Dielectric constant, activation energy, AC conductivity and dielectric loss measurements demonstrated that the nanocomposites outperformed the pure polymer blend. Complex impedance analysis revealed increased impedance with rising temperature. Overall, CG/PPy/ZnO nanocomposites exhibit superior optical, morphological, thermal, electrical, and dielectric properties, making them promising for energy storage and optoelectronic applications.Highlights Ecofriendly synthesis of CG/PPy/ZnO nanocomposites Enhancement in optical, structural, and thermal properties of CG/PPy/ZnO Dielectric properties and temperature‐dependent AC conductivity are summarized. Blend nanocomposite shows higher AC conductivity and dielectric constant CG/PPy/ZnO nanocomposites are suitable for energy storage applications

Eco-friendly synthesis, characterization, and properties of copper oxide nanoparticles in cashew gum/polypyrrole blend for energy storage applications

Conducting biopolymer blend nanocomposites of cashew gum (CG) and polypyrrole (PPy), with varying concentrations of copper oxide (CuO) nanoparticles were synthesized through an in-situ polymerization method using water as a sustainable solvent. The formation of blend nanocomposites was characterized using UV–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). UV spectroscopy revealed a significant reduction in absorption intensity with the addition of CuO, indicating enhanced optical properties. FT-IR and XRD analysis confirmed the successful incorporation of CuO into the CG/PPy blend. FE-SEM images revealed the uniform distribution of nanoparticles throughout the biopolymer blend, particularly in the 7 wt% sample. TGA and DSC results demonstrated a significant enhancement in thermal stability, increasing from 352 °C to 412 °C and a rise in the glass transition temperature from 89 °C to 106 °C in the blend nanocomposites. The dielectric constant, dielectric loss, impedance, Nyquist plot, electrical conductivity, and electric modulus were extensively examined at different temperatures and frequencies. The dielectric constant of the CG/PPy blend increased from 2720 to 92,950 with the addition of 7 wt% CuO, measured at 100 Hz. The improved glass transition temperature, thermal stability, and superior electrical properties imply potential usage of the developed nanocomposite in nanoelectronics and energy storage applications.

Antimicrobial potential and protein binding affinity of a hybrid ternary nanocomposite matrix: Zinc oxide functionalization with poly(vinyl alcohol)-sulphonated graphene oxide-poly pyrrole

The present study focuses on the application of a ternary PVA/sGO/ZnO-NP/PP nanocomposite as an antibacterial and antifungal agent. The process involved utilizing a solution casting technique to fabricate the inorganic–organic blend material, where 4-sulfophthalic acid (SPTA) was used in the sulfonation of graphitic oxide (GO) sheets. The amalgamation of polyvinyl alcohol polymer (PVA) and sulphonated GO (sGO) was achieved through a chemical oxidation polymerization process carried out in a water-based environment. This process developed a PVA/sGO film, in which zinc oxide nanoparticles (ZnO-NP) and pyrrole monomers were introduced. The PVA/sGO film served as the initial stage for the in-situ deposition and formation of polypyrrole (PP), leading to the fabrication of PVA/sGO/ZnO-NP/PP membrane. The structure was stabilized by hydrogen bonding and electrostatic interactions between the components, while SPTA acted as a cross-linker and a sulphonating agent. The Fourier transform infrared (FTIR) spectra of the quad-component composite unraveled the presence of distinctive functional groups, including PVA, sGO, PP, and Zn-O bands. The UV–visible spectra of PVA/sGO/ZnO-NP/PP nanocomposite membrane revealed a peak in the UV-B region, while in-depth X-ray diffraction (XRD) analyses provided strong evidence of its amorphous nature. The scanning electron microscopy (SEM) image showed that the top surface of the organic film was adorned with PP polymeric chains. The membrane exhibited great water retention capabilities due to its high ion exchange capacity (IEC) value.Additionally, the minimal water loss observed underscores its extended shelf life. Due to their inherent hydrophilic properties, the ternary nanocomposite membranes exhibited enhanced hydrophilicity, porosity, zeta potential, and water uptake. The BET and BJH analyses revealed that PVA/sGO/ZnO-NP/PP nanocomposites had a substantial surface area. Remarkably, the nanocomposite membrane exhibited significantly improved antimicrobial efficacy against bacteria and fungi. The type of interactions between Human serum lysozyme (HSL) and nanocomposite at the molecular level was studied through fluorescence spectroscopy. Stern-Volmer plot revealed the occurrence of both static and dynamic quenching. However, the precise mechanisms underlying the antimicrobial and protein binding (HSL) studies of PVA/sGO/ZnO-NP/PP-based nanocomposites require further investigation.

HZrO2@PPy nanocomposite for effective fluoride removal from environmental water

Fluoride contamination has become a worldwide concern since it can cause serious environmental problems. Zirconium-based adsorbents exhibit satisfactory fluoride removal capabilities. However, their narrow pH applicability, tendency to aggregate, and difficulty in separation hinder practical applications. Herein, a high efficiency hydrous ZrO2 polypyrrole nanocomposite (HZrO2@PPy) was prepared by in-situ oxidative polymerization. The results indicate that HZrO2@PPy exhibit optimal fluoride (F−) removal efficiency in a wide pH range (3−10), with good anti-interference performance to coexisting anions (Cl−, HSO4− and SO42–). The adsorption kinetics conformed to the quasi-second-order model and the adsorption process could reach equilibrium within 10 min. The adsorption isotherms are in good agreement with the Langmuir model, and the maximum adsorption capacity of F− at neutral pH could be 63.61 mg/g. Thermodynamic analysis shows that the adsorption defluorination of HZrO2@PPy is a spontaneous, endothermic, entropy-reducing reaction. In addition, the adsorption mechanism was investigated based on XPS and FTIR analyses. The results demonstrate that the electrostatic attraction, complexation effect and ion exchange are the main mechanisms for the adsorption of F− on HZrO2@PPy. The results presented in this work indicate the potential of the developed nanocomposite as a defluoridation material for environmental water.

Transfiguring energy with an advantageous supercapacitor integrating MoS2/carbon quantum dots bi‐composites into a high‐performance polypyrrole matrix for unprecedented efficiency

AbstractFor the first time, a simple one‐step in situ chemical polymerization technique is used to create a novel molybdenum disulphide/sulphonated carbon quantum dots (CQDs) and polypyrrole (MCP) nanocomposite that is extended for successful use in charge storage supercapacitor (SC) device. By inheriting qualities of excellent electrical conductivity of MoS2, CQDs and improved pseudocapacitive activity of polypyrrole (PPy), the MCP nanocomposite provides a suitable SC electrode material. 0.6 MCP nanocomposited three‐electrode system demonstrates 93.21% retention after 5000 cycles, and a maximum specific capacity of 2253 F/g at 2 mV/s with higher side of energy density as 106.06 Wh/kg along with a considerable power density as 180.28 W/kg. Using MCP as anode and an AC or activated charcoal electrode as cathode, a solid‐state asymmetric supercapacitor (ASC) was constructed. The fabricated device supplies a greater value of specific capacitance as 154.09 F/g at 100 mV/s and 175 F/g at 0.1 A/g, also evidenced superior energy density data as 126 Wh/kg along with an appreciable power density of 604.8 W/kg. After charging the ASC for 2 min, the light emitting diode shone for 5 min. The findings underpin that MCP is a potential electrode material that could be utilized as a better alternative in futuristic supercapacitor devices.

Facile synthesis and electrochemical investigation of graphitic carbon nitride/manganese dioxide incorporated polypyrrole nanocomposite for high-performance energy storage applications

Abstract Manganese dioxide (MnO2) nanoparticles were modified by graphitic carbon nitride (GCN) and polylpyrrole (Ppy) to enhance their electrochemical performance. The surface influence, crystalline structure, and electrochemical performance of the Ppy/GCN/MnO2 material were characterized and compared with those of pristine MnO2. It is found that surface modification can improve the structural stability of MnO2 without decreasing its available specific capacitance. The electrochemical properties of synthesized Ppy/GCN/MnO2 electrode were evaluated using cyclic voltammetry (CV) and AC impedance techniques in 5 M KOH electrolyte. Specific capacitances of 486, 815, 921, and 1377 F/g were obtained for MnO2, Ppy/MnO2, GCN/MnO2, and Ppy/GCN/MnO2, respectively, at 5 A/g. This improvement is attributed to the synergistic effect of GCN and Ppy in the Ppy/GCN/MnO2 electrode material. The Ppy/GCN/MnO2 electrode in KOH has average specific energy and specific power densities of 172 Wh kg−1 and 2065 W kg−1, respectively. Only 2 % of the capacitance’s initial value is lost after 10,000 cycles. The resulting Ppy/GCN/MnO2 nanocomposite had very stable and porous layered structures. This work demonstrates that Ppy/GCN/MnO2 nanomaterials exhibit good structural stability and electrochemical performance and are good materials for supercapacitor applications.

Investigating and characterizing electrical properties of polypyrrole/SiO2/FePS3 nanocomposite

AbstractNovel nanocomposites of polypyrrole (PPy) embedded in silica (SiO2) and iron phosphorus trisulphide (FePS3) nanoparticles have been fabricated. The nanocomposite's dielectric characteristics have been examined in relation to temperature ranges of 25–200°C and frequency ranges of 0.1–7 MHz. Fourier‐transform infrared spectroscopy (FTIR), x‐ray diffraction (XRD), scanning electron microscopy (SEM–EDX), transmission electron microscope (TEM), and dielectric measurements have all been used to evaluate the prepared nanocomposite. The monoclinic crystal structure of the prepared FePS3 and PPy/SiO2/FePS3 nanocomposite is confirmed by XRD, EDX, and TEM studies. The FePS3 is perfectly layered structure in the SEM image, and FePS3 and SiO2 particles are well intercalated, creating novel nanocomposites of two nanoparticle phases that served as a union network during the polymerization process. The IR spectrum shows that PPy is a dopant in the interlayer area of FePS3. The splitting major peak (570 cm−1) of FePS3 is visible at around 640 and 560 cm−1. The high AC conductivity values indicated that the combination of FePS3/SiO2 nano‐matrix contains PPy at high packing densities and confirming the semiconducting properties of the nanocomposite to be used in several electronic applications.

Unveiling the Influence of Metal Oxides on Multifaceted Polypyrrole Nanocomposite Properties

Unveiling the Influence of Metal Oxides on Multifaceted Polypyrrole Nanocomposite Properties

Electrochemical sensor based on nanocomposite of nickel oxide nanoparticles and polypyrrole for the detection of metoprolol as a doping agent in biological fluids and food samples

Electrochemical sensor based on nanocomposite of nickel oxide nanoparticles and polypyrrole for the detection of metoprolol as a doping agent in biological fluids and food samples

Determination of vitamins K1, K2, B6, and D3 using reduced graphene oxide fabricated using a bismuth nanoparticle embedded polypyrrole nanocomposite based optical sensor

Detection of vitamins K1, K2, B6, and D3 in human blood serum/plasma using the reduced Graphene Oxide fabricated with bismuth nanoparticles embedded polypyrrole nanocomposite (rGO/pPy/Bi NC) as an optical sensing material.

Adsorptive avidity of Prussian blue polypyrrole nanocomposite for elimination of water contaminants: a case study of malachite green and isoniazid.

Persistent water contaminants include a variety of substances that evade natural cleaning processes posing severe risks to ecosystems. Their adsorptive elimination is a key approach to safer attenuation. Herein we present the design and development of Prussian blue incorporated polypyrrole (PPY/PB) hybrid nanocomposite as a high-performance adsorbent for the elimination of malachite green (M.G.), isoniazid (INH) and 4-nitrophenol (4-NP) water contaminants. The nanocomposite synthesis was favored by strong dopant-polymer interactions, leading to a PPY/PB material with enhanced electro-active surface area compared to pristine PPY. The structure-activity response of the nanocomposite for the adsorption of target contaminants was unveiled by evaluating its maximum adsorption capacities under environmentally viable conditions. In-depth analysis and optimization of adsorption influencing factors (pH, temperature, and adsorbent dose) were performed. Using equilibrium studies, kinetic model fitting, aided with FTIR analysis, a multi-step mechanism for the adsorption of target contaminants on the nanocomposite was proposed. Furthermore, the PPY/PB nanocomposite also acts as a catalyst, enabling contaminant elimination following a synergistic scheme that was demonstrated using 4-NP contaminant. The synergetic adsorption and catalytic degradation of 4-NP using PPY/PB as adsorbent and catalyst was demonstrated in the presence of NaBH4 as a reducing agent in absence of light. In summary, this work highlights the targeted design of adsorbent, its optimization for adsorptive avidity, and the synergistic role of adsorption trapping in the catalytic degradation of persistent contaminants.

Fabrication of Multiwalled Carbon Nanotubes (MWCNT) and Reduced Graphene Oxide (rGO)‐based thermoplastic polyurethane and polypyrrole nanocomposites for electromagnetic wave absorption application with a low reflection

AbstractElectromagnetic radiation (EMR) pollution is a serious concern in today's environment, causing problems not just for electronic gadgets but also for living society. The goal of this research is to fabricate thermoplastic polyurethane (TPU) and polypyrrole (PPy)‐based 95:5 blend nanocomposites using a simple solvent casting method at such a low concentration of rGO and MWCNT (0.3, 0.4, 0.5 php) (parts per hundred polymers), for electromagnetic wave (EMW) absorption applications. The chemical interaction between the different phases and morphology of the nanocomposites is characterized by Raman spectroscopy, X‐ray diffraction (XRD), and field emission scanning electron microscopy (FESEM) techniques. The material properties, such as dielectric and magnetic properties, are analyzed in X‐band frequency (8.2–12.4 GHz). The total shielding effectiveness of (SETot) 0.5 rGO system is found to be 27 dB, whereas, for corresponding MWCNT nanocomposites, it is 26 dB. Interestingly, in 0.5 rGO nanocomposites, absorption shielding effectiveness (SEAbs) is approximately 25 dB, and reflection shielding effectiveness (SERef) is less than 2 dB, which indicates the absorption of 70% of the electromagnetic wave, and the rest gets reflected. Apart from that, the rGO‐based nanocomposites possess a greater extent of thermal stability than the corresponding MWCNT‐based nanocomposites.Highlights Fabrication of TPU‐PPy‐rGO and TPU‐PPy‐MWCNT nanocomposites by solvent casting. Low reflection of TPU‐PPy‐rGO nanocomposites with a 70% absorption rate. FESEM confirms the multilayer interface structures. Tunable Dielectric and magnetic properties of nanocomposites in X‐band. Excellent absorption dominant properties of the fabricated nanocomposites.

A flexible capacity-metric creatinine sensor based on polygon-shape polyvinylpyrrolidone/CuO and Fe2O3 NRDs electrodeposited on three-dimensional TiO2–V2O5–Polypyrrole nanocomposite

The innovations of the present work include these items; (i) Design and preparation of three-dimensional flexible conductive polymeric nanocomposites (3D-FCPNCs) containing polypyrrole (PPy), V2O5 and TiO2 and modification of their surface with polygon-shape polyvinylpyrrolidone/CuO nanorods (PVP/CuO NRDs) and Fe2O3 NRDs using an hierarchical process based on isoelectric point (IEP), (ii) Application of the prepared surfaces as the flexible enzymeless creatinine sensors using four calibration curves (impedimetric, real capacitance (C′), imaginary capacitance (C″) and double layer capacitance (Cdl)) obtained from electrochemical impedance spectroscopy (EIS) technique. The best results have been obtained using PVP/CuO NRDs–Fe2O3 NRDs/TiO2–V2O5–PPy 3D-FCPNC hierarchical electrode with a wide range of the linear concentration range (10 nmol L−1 −1.3 mmol L−1). Although, determination of creatinine through extraction of parameters such as charge transfer resistance (Rct) and Cdl from measuring impedance at a wide range of frequencies provides useful information about the characteristics of the electrolyte/electrode interface, but measuring real and imaginary capacitances at a specific frequency instead of a wide frequency range can decrease the response time to lower than 1 min. Finally, the prepared hierarchical enzymeless sensors have been successfully used to estimate creatinine concentration in blood serum.

NixCu3−x(HHTP)2 decorated poly-pyrrole porous nanocomposites for highly selective and stable hydrogen sulfide sensing at room temperature

Hydrogen sulfide (H2S) sensing with high selectivity and stability is required for environmental monitoring at room temperature, however, needs further exploring. Here, NixCu3−x(HHTP)2 decorated over poly-pyrrole nanocomposites {NixCu3−x(HHTP)2/PPy NCPs, HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene} have been developed for highly selective and stable H2S sensing at room temperature (∼ 25 ⁰C), which have been synthesized by firstly oxidating polymerizing poly-pyrrole nanoparticles and subsequently decorating with NixCu3−x(HHTP)2 metal-organic frameworks (MOFs) via a hydrothermal process. Typically, the NixCu3−x(HHTP)2/PPy NCPs are observed with spiny surface and are characterized with amorphous crystallization. Beneficially, the NixCu3−x(HHTP)2/PPy NCPs show excellent selectivity to H2S even in the presence of other interfering gases and display a 70 days-long stability that maintains 77.3% response at room temperature (∼ 25 ⁰C). Further, the sensor prototypes enable to detect H2S as low as 500 ppb and show stability against humidity, respectively. Theoretically, such excellent H2S sensing performance might be attributed to the charge transfer between H2S molecules and utilized copper, fast charge transports via forming bimetallic MOFs and the counteraction of PPy NPs to interfering gas. Practically, a H2S sensing device built with the NixCu3−x(HHTP)2/PPy prototype has been integrated to detect H2S with excellent sensing response.

Mixed metal oxide decorated polypyrrole nanocomposites for multifunctional applications

Mixed metal oxide nanocomposites of TiO2, ZnO, and CuO were synthesized by the improved Sol-gel method. Polymerization of polypyrrole (PPy) was carried out by chemical oxidative technique. In situ technique was used to synthesize mixed metal/PPy nanocomposites. The photocatalytic, antibacterial, anticorrosive, electrical, and magnetic properties of polymeric nanocomposites were investigated. The photosensitivity of polymeric nanocomposites was examined for degrading methylene blue dye in visible light. The variation in pH and Chemical Oxygen Demand (COD) with the degradation time of dye was followed. pH increases and COD decreases with an increase in photodegradation of dye with time. The antibacterial properties of polymeric nanocomposites and metal oxide nanocomposites were investigated against E. coli and B. subtilis and compared with 06 antibiotics (Hexa disk). The optical band gap of metal oxide nanocomposites, PPy, and PPy/mixed metal oxide nanocomposites was investigated by Tauc plots. The photocatalytic degradation of methylene blue follows pseudo 1st-order kinetics with a velocity constant of 0.0685 min−1. The mixed metal/PPy nanocomposites show 80.1 ± 0.2 % corrosion inhibition efficiency. The maximum zone of inhibition shown by mixed metal nanocomposites was 12.5 ± 0.1 mm against E. coli. The mixed metal/PPy nanocomposites (100 ppm) degrade 92 % of the methylene blue dye after 90 min. of visible light exposure. The magnetic properties show a high degree of magnetization retention in polymeric nanocomposites. Mixed metal/PPy nanocomposites show very good photocatalytic, antibacterial, anticorrosive, electrical, and magnetic properties and hence act as advanced functional nanomaterials for multifunctional applications.