PANI Content Research Articles

High-Visible Light Response AgNbO3/Bi2MoO6/PANI Double Z-Scheme Heterojunction Photocatalytic Degradation of Antibiotics.

In this study, a novel AgNbO3/Bi2MoO6/PANI double Z-scheme heterojunction photocatalyst was created via a solvothermal method, and the method investigates its photocatalytic degradation performance toward norfloxacin (NOR) and other antibiotics. When the content of AgNbO3 is 5 wt % and the content of PANI is 1 wt %, the rate of degradation of AgNbO3/Bi2MoO6/PANI on NOR under visible light is 95.56%, the rate of removal of total organic carbon is ∼57.45%, and its pseudo-first-order reaction rate constant is 0.01878 min-1, which surpasses those of AgNbO3, Bi2MoO6, and AgNbO3/Bi2MoO6 by factors of 14.22, 2.46, and 1.35, respectively. At the same time, the AgNbO3/Bi2MoO6/PANI photocatalyst still showed good stability after three cycles. The results demonstrated that the augmented photocatalytic performance of AgNbO3/Bi2MoO6/PANI can be attributed to the formation of a double Z-scheme heterojunction and the incorporation of PANI with excellent conductivity, resulting in the higher efficiency of migration of charge carriers while retaining strong redox ability. This work affords a high-efficiency and environmentally friendly reference for the development of a Bi2MoO6-based heterojunction photocatalyst and its application in the purification of antibiotics in water.

Functional post-processing of extrusion-based 3D printed parts: polyaniline (PAni) as a coating for thermoplastics components

PurposeThis study aims to evaluate in situ oxidative polymerization of aniline (Ani) as a post-processing method to promote extrusion-based 3D printed parts, made from insulating polymers, to components with functional properties, including electrical conductivity and chemical sensitivity.Design/methodology/approachExtrusion-based 3D printed parts of polyethylene terephthalate modified with glycol (PETG) and polypropylene (PP) were coated in an aqueous acid solution via in situ oxidative polymerization of Ani. First, the feedstocks were characterized. Densely printed samples were then used to assess the adhesion of polyaniline (PAni) and electrical conductivity on printed parts. The best feedstock candidate for PAni coating was selected for further analysis. Last, a Taguchi methodology was used to evaluate the influence of printing parameters on the coating of porous samples. Analysis of variance and Tukey post hoc test were used to identify the best levels for each parameter.FindingsColorimetry measurements showed significant color shifts in PP samples and no shifts in PETG samples upon pullout testing. The incorporation of PAni content and electrical conductivity were, respectively, 41% and 571% higher for PETG in comparison to PP. Upon coating, the surface energy of both materials decreased. Additionally, the dynamic mechanical analysis test showed minimal influence of PAni over the dynamic mechanical properties of PETG. The parametric study indicated that only layer thickness and infill pattern had a significant influence on PAni incorporation and electrical conductivity of coated porous samples.Originality/valueCurrent literature reports difficulties in incorporating PAni without affecting dimensional precision and feedstock stability. In situ, oxidative polymerization of Ani could overcome these limitations. However, its use as a functional post-processing of extrusion-based printed parts is a novelty.

Dual-aeolotropic electrically conductive flexible composite membrane with enhanced red fluorescence

New-typed dual-aeolotropic conductive flexible composite membrane (DCFCM), was devised and fabricated by parallel electrospinning. DCFCM consists of two layers that are strongly coupled to form a top-to-bottom structure. Janus nanoribbon (JN), possessing two distinct sides (respectively conducting and insulating-fluorescent side), is highly oriented in each layer of DCFCM. The top-to-bottom structure of DCFCM effectuates the macro-level zoning, and the JN as a conductive and constitutive function in DCFCM realizes the micro-level zoning, which achieves the combination of microstructure and macroscopic structure in DCFCM. Thus, DCFCM simultaneously performs dual-aeolotropic electrical conduction and enhanced red luminescence due to the partitioning structures which aid in minimizing adverse interactions between the conductive and luminescent materials. The conducting anisotropy of each layer in the DCFCM can be adjusted by varying the PANI content. The conductance ratio can reach 108 when the PANI content is 60–70 %. Additionally, DCFCM exhibits strong red emission, originating from the allowed 5D0→7F2 (593 nm), 5D0→7F2 (616 nm) energy levels transitions of Eu3+ ions. This work provides a simple and effective method to fabricate aeolotropic conductive membranes with novel multifunctional properties.

Preparation and corrosion resistance of polyaniline and waterborne polyurethane composite coating film

AbstractPolyaniline (PANI) particles were synthesized using aniline (AN), dodecyl benzene sulfonic acid (DBSA), and ammonium persulfate (APS). The particles were analyzed using scanning electron microscope (SEM), X‐ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). A PANI/waterborne polyurethane composite material (PANI‐WPU) was obtained by combining it with polyethylene glycol (PEG600), diphenylmethane diisocyanate (MDI), dimethylol propionic acid (DMPA), N‐methyl pyrrolidone (NMP), and dibutyltin lauric acid (DBTDL). The structure was characterized by the FTIR spectrum. The mechanical characteristics of the coating film were evaluated with respect to the PANI content, as well as its water absorption, glossiness, electrochemical corrosion resistance, and acid and alkali resistance. The PANI/waterborne polyurethane film has a maximum tensile strength of 23 MPa, an elongation of 1012%, a pencil hardness of 5H, a flexibility of 2 mm, an impact resistance of 50 cm, the water absorption of 14.66%, and the glossiness of 99.9 at 60°. When the PANI content is 0.7%, the mechanical characteristics, glossiness, and anti‐corrosion performance of the composite film improve. The corrosion inhibition efficiency of the aqueous polyurethane coating film with PANI can reach 99.74%, as shown by the examination of electrochemical polarization curves and impedance spectra. The tinplate is coated with a 0.7% PANI‐WPU composite material and edge sealing. This coating provides excellent protection against acid and alkali resistance, as demonstrated by its ability to withstand immersion in 10% H2SO4 and 10% NaOH solution for 90 days without any paint peeling off.

The effect of polyaniline composition on the polyurethane/polyaniline composite properties: The enhancement of electrical and mechanical properties for medical tissue engineering

<abstract> <p>This study addresses the urgent need for the preparation and characterization of conductive polyurethane/polyaniline (PU/PANI) polymers for medical device applications, particularly in the context of the COVID-19 situation. Composite films of PU/PANI were synthesized using the solution casting method. Fourier-transform infrared (FT-IR) results confirmed the presence of PANI, as indicated by absorption bands at 1597 and 1531 cm<sup>−1</sup> corresponding to C = C and C–N stretching, respectively. Microscopic analyses using scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrated a homogeneous distribution of PANI in the PU matrix up to approximately 3 wt.%, with inhomogeneity observed at 5 wt.%. The dielectric constants at 1 Hz for PANI contents of 1, 3, and 5 wt.% in the PU matrix were 12.5, 18.5, and 35.0, respectively. The conductivity exhibited a decreasing trend with an increasing driving frequency. Conversely, for comparative purposes, the dielectric and conductivity values increased with higher PANI contents. The elastic modulus slightly increased from 20.3, 20.8, and 21.2 for 1, 3, and 5 wt.%, respectively. The experimental results emphasize the superior mechanical-to-electrical conversion performance of PU/PANI composites compared to neat PU, thus indicating potential applications in medical tissue engineering that utilize conductive PU/PANI polymers.</p> </abstract>

Electromagnetic wave absorption, EMI shielding effectiveness and electrical properties of ethylene – vinyl Acetate (EVA)/ Polyaniline (PAni) blends prepared by in situ polymerization

Flexible, low cost and scalable microwave absorbing materials are very important for application in the telecommunication area and also in stealth technology for military purpose. In the present work, polyaniline doped with dodecylbenzene sulfonic acid (PAni.DBSA) was synthesized in the presence of ethylene vinyl acetate (EVA) copolymer by in situ inverted emulsion polymerization and the corresponding composites were explored as potential electromagnetic wave absorbing materials and electromagnetic interference shielding materials in the X- and Ku-band frequency range. The properties of the composites, such as rheological, electrical and dielectric properties, were investigated as a function of the composite composition. The findings reveal that the microwave absorption of EVA@PAni composites is influenced by the PAni content, with the optimal attenuation achieved by the composite with 33 vol % PAni. This composite displays superior microwave absorbing performance, with a minimum reflection loss of −39 dB (99.99 % attenuation) at 16.65 GHz. This study demonstrates the potential of EVA@PAni composites as microwave-absorbing materials, mainly in the higher frequency range (Ku band) and open new possibilities of developing flexible, low-cost, lightweight and processable materials for applications in both civil and military field.

Extracellular matrix-mimetic electrically conductive nanofibrous scaffolds based on polyaniline-grafted tragacanth gum and poly(vinyl alcohol) for skin tissue engineering application

As pivotal role of scaffold in tissue engineering (TE), the aim of present study was to design and development of extracellular matrix (ECM)-mimetic electrically conductive nanofibrous scaffolds composed of polyaniline-grafted tragacanth gum (TG-g-PANI) and poly(vinyl alcohol) (PVA) with different PANI content for skin tissue engineering (STE) application. The fabricated scaffolds were preliminary evaluated in terms of some physicochemical and biological properties. Cytocompatibility and cells proliferation properties of the scaffolds were examined with the well-known MTT assay, and it was found that the developed scaffolds have proper cytocompatibilities and can enhances the mouse fibroblast L929 cells adhesion as well as proliferation, which confirm their potential for STE applications. Hemocompatibility assay revealed that the hemolysis rate of the fabricated scaffolds were <2 % even at a relatively high concentration (200 μgmL−1) of samples, therefore, these scaffolds can be considered as safe. Human serum albumin (HSA) protein adsorption capacities of the fabricated scaffolds were quantified as 42 and 49 μgmg−1 that represent suitable values for a successful TE. Overall, the fabricated scaffold with 20 wt% of TG-g-PANI showed higher potential in both physicochemical and biological features than scaffold with 30 wt% of mentioned copolymer for STE application.

Interpenetrating shape memory polyimide‐polyaniline composites with electrical conductivity

AbstractShape memory polyimides (SMPI) with adjustable shape recovery temperatures have been paid much attention in both fundamental research and practical applications. However, the intrinsically electrical insulation of SMPIs limits their applications. In this article, the electrically conductive shape memory polyimide‐polyaniline (SMPI‐PANI) composite with interpenetrating networks was synthesized by in situ polycondensation. Compared with pure SMPI, the electrical resistivity of SMPI‐PANI composites reduced by about 12 orders of magnitude when the PANI content was 15 wt%. The addition of PANI had less influence on the glass transition temperature and storage modulus in glassy state. But the storage modulus of SMPI‐PANI composites in rubbery state was over 40 times higher than that of pure SMPI, indicating that SMPI‐PANI composites have higher stiffness during shape recovery. The SMPI‐PANI composites demonstrate excellent shape memory performance with shape fixation ratio higher than 97% and shape recovery ratio higher than 93%. The SMPI‐PANI composites also have good thermal stability with the effective decomposition temperatures higher than 150°C. The SMPI‐PANI composite in our work is a potential material for deployable aerospace structure.

Novel SnO2/PAni nanocomposites for selective detection of ammonia at room temperature

The present study aims to investigate a new method of SnO2/polyaniline (PAni) nanocomposite sensor fabrication for detection of ammonia at different temperatures including the room one. The fabrication of composite is performed by synthesis of PAni according to oxidative polymerization. Then the SnO2/PAni hybrid nanocomposites containing different percentages of polymer were fabricated by a deposition–precipitation method in presence of SnCl4 solution. The produced powders were characterized by XRD, BET, FTIR, Raman, TGA and FESEM tests. By increasing PAni contents of the nanocomposites, SnO2 crystallite sizes decrease, the surface area increases, and thermal stability improves. The sensing behavior of SnO2/0–30 wt% PAni in presence of 100–500 ppm ammonia was measured. The SnO2/8 wt% PAni shows the best sensitivity, where the response of sensor for 100 ppm NH3 at room temperature is about 187 %. Optimum heteronucleation and decoration of SnO2 on PAni surface enhances the response. Moreover, the sensor is selective in presence of interfering gases including CO, ethanol, methane, toluene and trichloroethylene.

Iron Doped Titania/Polyaniline Composite: An Efficient Electrocatalyst for Hydrogen Evolution Reaction in Acidic Medium

The development of noble metal-free catalyst for hydrogen evolution reaction (HER) is the primary challenge in fuel production to replace fossil fuels. Here, we have synthesized Fe-doped TiO&lt;sub&gt;2&lt;/sub&gt;/PANI nanocomposite via facile in situ polymerization method and studied its electrocatalytic activity towards HER. The composite catalyzes HER efficiently with an overpotential value of -180 mV vs. RHE in 0.5 M H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; solution to achieve the current density of 10 mA cm&lt;sup&gt;-2&lt;/sup&gt; and also possesses unique stability of 8 h. However, a unique balance of PANI content must be maintained to draw the maximum efficiency from the conjuncture of active Fe-doped TiO&lt;sub&gt;2&lt;/sub&gt; particles and PANI. The catalytic efficiency of PANI is upgraded by interfacial electronic coupling with Fe-doped TiO&lt;sub&gt;2,&lt;/sub&gt; due to which the antibonding states of nitrogen atom got occupied, leading to a weaker interaction between adsorbate hydrogen and catalyst surface and enhancing the rapid desorption of H&lt;sub&gt;2&lt;/sub&gt;.

Bifunctional manganese ferrite nanoparticles: Tuning their efficiency for aniline polymerization and polyaniline nanocomposites for boosting adsorption of organic dyes

AbstractThe uniqueness of this work is the comparison of manganese ferrites/polyaniline (MnxFe3 − xO4/PANI) produced using K2S2O8 as an oxidant for aniline with the efficacy of spinel manganese ferrite with various Mn2+ ratios for the polymerization of aniline. The structural and morphological properties of the nanocomposites were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT‐IR), X‐ray powder diffraction (XRD), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), transmission electron microscopy (TEM), and Brunauer‐Emmett‐Teller (BET) techniques. XRD results confirmed the formation of a single‐phase cubic spinel structure with a lattice constant of approximately 8.3 Å. The surface enriched by Mn2+ exhibited an enhanced valence of +3 and +4, increased lattice oxygen content, facilitated ferrite reduction, and improved the oxidative performance of Fe3+. The saturation magnetization decreased with an increase in Mn+2 ratios and PANI contents. The nanocomposites exhibited excellent adsorption of Lanaset Brown B dye, which was investigated as a model textile dye. Various adsorption capacities (qmax) for the nanocomposites were calculated in a range of 122.39–215 mg/g, depending on the synthesis conditions. Optimization parameters, such as pH, adsorbent dose, and initial concentration, as well as reusability, were described. The Langmuir isotherm is a better model for describing the adsorption process of the nanocomposites. An evaluation of thermodynamic parameters suggests the sorption process is feasible, spontaneous, and endothermic.

Development of polyaniline coated titania-hematite composite with enhanced photocatalytic activity under sun-like irradiation

Herein, a novel PANI@Fe2O3@TiO2 (PANI@TF) composite containing different amounts of polyaniline was synthesized by in situ polymerization of aniline monomer in the presence of TF. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), BET surface area, Diffuse reflectance spectroscopy (DRS), X-ray photoelectron (XPS), and scanning electron microscopy (SEM-EDS) were used to study the phase structure, morphology, and optical properties of the synthesized PANI@TF composites. Moreover, for the first time, the photocatalytic property of the as-synthesized PANI@TF composites has been evaluated via the decolorization of MB under sun-like illumination. The findings confirmed that all the PANI@TF ternary composites with different PANI content showed enhanced visible-light photocatalytic activity for methylene blue (MB) dye degradation compared to pure Fe2O3@TiO2. The highest degradation efficiency for MB via 1% PANI@TF ternary catalyst reached 96% after 2 h under sun-like illumination, which was 4.3 higher than TF. Finally, a plausible photocatalytic mechanism for the improved photocatalytic activity was proposed to guide further improvement of its photocatalytic performance.

Simultaneous Cryogenic Radical and Oxidative Coupling Polymerizations to Polyaniline/Polyacrylamide Conductive Cryogels for Gas Sensing.

The macro-porous structure of polymer cryogels provides an appropriate channel for the adsorption and transport of substances, endowing its application in the field of electrochemical sensing. The combination mode of a polymer matrix and electro-active substance, particularly the distribution of an electro-active substance in the matrix, has an important effect on the overall performance of the sensor. In this work, through the simultaneous oxidation coupling polymerization of aniline (ANI) and radical polymerization of acrylamide (AAm) under cryogenic condition, conductive composite cryogels were prepared, aiming for the uniform distribution of PANI in the PAAm matrix. The possibility of simultaneous polymerizations was symmetrically investigated, and the obtained PANI/PAAm cryogels were characterized. Due to the acid-doping of PANI, the electrical conductivity of PANI/PAAm cryogels could be modulated with acidic and basic gases. Thus, the performance of the gas sensor was studied by making conductive PANI/PAAm cryogel sheets as resistive sensor electrodes. We found that the content of PANI, the sheet thickness and the dry/wet state of the cryogel influenced the response sensitivity and rate as well as the recovery properties. The response duration for HCl and NH3 gas was shorter than 70 and 120 s, respectively. The cyclic detection of HCl gas and the alternate detection of NH3/HCl were achieved. This gas sensor with advantages, including simple preparation, low cost and high sensitivity, would have great potential for the application to monitor the leakage of acidic and basic gases.

Carboxymethylcellulose-polyaniline/carbon nanotube (CMC-PANI/CNT) film as flexible and highly electrochemical active electrode for supercapacitors

Herein, we demonstrate a flexible, structural robust and highly electrochemical active film electrode based on evenly distributed carboxymethylcellulose-polyaniline/carbon nanotube (CMC-PANI/CNT) for supercapacitors. In this process, vertically aligned PANI nanoparticles grow in an orderly manner on CMC fibers. The highly dispersed CNT nanomaterials are then introduced by simple layer-by-layer assembly, eventually forming an interwoven network structure. Mechanical tests have shown that the obtained CMC-PANI/CNT film exhibit excellent robustness and flexibility, and can be used directly as electrodes without any conductive additives and binders. The CMC-PANI/CNT electrode with optimal CMC, PANI and CNT contents demonstrates an excellent area specific capacitance of 3106.3 mF cm−2 at 5 mA cm−2 and a gravimetric specific capacitance of 348.8 F g−1 at 0.5 A g−1. Furthermore, the symmetric supercapacitor (SSC) assembled with CMC-PANI/CNT exhibits a high energy density of 99.89 μW h cm−2 at a power density of 400.02 μW cm−2, and a good cycling stability (with capacitance retention of 89.2 % after 5000 cycles). The cost-effective and eco-friendly preparation method of free-standing CMC-PANI/CNT film electrodes provide a novel insight for developing flexible energy storage devices.

Design of polyaniline encapsulated greigite(Fe3S4) microparticles for excellent microwave absorption performance with broad bandwidth and ultrahigh reflection loss

Exploring microwave absorption materials with the advantages of wide effective absorption bandwidth, thin thickness, strong absorption capacity and light weight is significant to solving the problems of electromagnetic (EM) irradiation in both military and civil areas. Herein, to make up for the weaknesses of single component Fe3S4 or polyaniline in microwave absorption performance, the composites with extraordinary microwave absorption performance composed of Fe3S4 encapsulated in polyaniline was elaborately designed. The successful synthesis and the microwave absorption mechanisms of Fe3S4@PANI composites were demonstrated by several characterizations. The results indicated that the dielectric constant of the composites can easily be adjusted by the content of PANI in favor of the impedance matching within the frequency range. Therefore, the sample F–P-2 presented the optimum performance, the minimum reflection loss (RLmin) value and broadest effective absorption bandwidth (EAB) respectively reach −63.8 dB at 7.68 GHz and 5.04 GHz (ranging from 12.88 to 17.92 GHz) under 40 wt% loading. Such good performance could be dependent on multiple loss mechanisms, such as the interface and dipole polarization, conduction loss as well as the multiple reflection and scattering. Based on the excellent properties and simple preparation methods, the Fe3S4@PANI composites can be a potential candidate in military and civil microwave absorption field.

Fabrication of one-dimensional M (Co, Ni)@polyaniline nanochains with adjustable thickness for excellent microwave absorption properties

The development of microwave absorbing materials with strong absorption capacity, wide bandwidth and light weight has always been a topic of concern. Herein, one-dimensional (1D) M (Co, Ni)@polyaniline (PANI) nanochains (NCs) with adjustable thickness have been successfully synthesized by reducing the mental ions under a parallel magnetic field, pretreating metal nanochains with KH550 and pre-oxidization of aniline monomer. It is found that Co has a more favorable absorption width for electromagnetic waves (EMW) and Ni aims at the absorption intensity. Furthermore, the effect of metal elements on adjusting impedance matching is more significant than their magnetic loss for composites. The minimum reflection loss (RLmin) of CoP2 can be up to −73.16 dB at 4.63 mm and the effective absorption bandwidth (EAB) is 4.98 GHz at 2.17 mm, while those of NiP2 are −65.06 dB at 3.88 mm and 5.02 GHz at 2.05 mm. The increase of PANI content can significantly reduce the matching thickness. And the RLmin of CoP3 and NiP3 can reach −58.72 dB at 2.32 mm and −65.96 dB at 1.59 mm, respectively. The absorption mechanism reveals that the matching thickness of the quarter-wavelength determines frequency location. And high absorption intensity is attributed to the synergistic effects of impedance matching, conduction loss, polarization loss, and magnetic loss. This work provides a theoretical basis for designing PANI or other conducting polymers coating magnetic nanochains for electromagnetic absorbing materials with strong absorption capacity, wide bandwidth and light weight.

Study on properties of hydrogenated nitrile butadiene rubber filled with polyaniline compound silica

AbstractPolyaniline was synthesized by chemical oxidation polymerization, and polyaniline‐silica (PANI‐SiO2) nanocomposites were prepared by precipitation method. A reinforced PANI‐SiO2/HNBR was obtained by filling the PANI‐SiO2 composites into hydrogenated nitrile rubber (HNBR). The amino cations contained in acid‐doped PANI can electrostatically attract SiO32−, so that SiO2 can grow directly on the surface of PANI, thus reducing the agglomeration of silica and improving the mechanical properties of reinforced rubber. The effect of PANI and PANI‐SiO2 composites on mechanical properties of hydrogenated nitrile butadiene rubber was studied. The results show that PANI improves the dispersion of SiO2 in HNBR. When the PANI‐SiO2 composite (PANI content of 2%) in PANI‐SiO2/HNBR is 30 phr, the filler network is the weakest, and the dispersion of filler is the best in rubber, the maximum tensile strength of PANI‐SiO2/HNBR is 30.31 MPa, which is 1.87 times that of SiO2/HNBR, the tear strength is 27.7 MPa, which is 129.4% of that of SiO2 reinforced packing with the same number of components. The hardness and elongation at break both increase. In addition, the permanent tensile deformation of PANI‐SiO2/HNBR is also reduced.

Plasma Oscillation Behavior and Electromagnetic Interference Shielding of Carbon Nanofibers/Conductive Polymer Metacomposites at Radarwave Frequency.

Metacomposites have attracted widespread attention due to their unique negative electromagnetic properties and stupendous applications. Although there are systems that realize metamaterial properties in low radio frequency bands, the research on the construction of polymer matrix metacomposites with negative performance in the pivotal GHz band is still undiscovered. Herein, carbon nanofiber/conductive polymer metacomposites with 3D overlapping network structures are innovatively constructed to achieve negative permittivity characteristics in the radarwave frequency range, and convenient methods for further adjusting the electromagnetic parameters is also proposed. The results show that the negative permittivity of CNFs/PANI metacomposites can be conveniently altered via adjusting PANI content. Furthermore, electromagnetic shielding has also been fully discussed as one of the most valuable applications of the metacomposites. The SET of CNFs/PANI-70 has an average value of 70dB at 4-18GHz and can reach a maximum of 80dB at 4GHz, which far exceeds the current commercial electromagnetic shielding standards. This work greatly broadens the promising application of metacomposites for perfect electromagnetic shielding, novel capacitance, and frequency selective surfaces.

Ultra‐Durability and Enhanced Activity of Amorphous Cobalt Anchored Polyaniline Synergistic towards Electrocatalytic Water Oxidation

AbstractCobalt anchored polyaniline electrocatalysts (Co@PANI) have been synthesized (Co@PANI‐200, Co@PANI‐400, Co@PANI‐600, Co@PANI‐800) and characterised. The electrical conductivity and stability of Co@PANI increased due to the synergistic effect of PANI and cobalt content. PANI prevents aggregation and show strong binding with cobalt ions. The Co@PANI‐600/GC shows low overpotential of 341 mV @ 10 mA cm−2 current density and the Tafel slope of Co@PANI‐600 (39 mV dec−1) was smaller than IrO2 (98 mV dec−1) for OER. The calculated turnover frequency (TOF) of Co@PANI‐600/GC (0.01609 s−1) was ≈8 times higher than IrO2 (0.0014 s−1) at 1.60 V. Furthermore, the Co@PANI‐600/NF electrocatalyst shows an incredibly low overpotential of 251 mV @10 mA cm−2. This new born Co@PANI‐600/NF exhibits durability over 250 h with only 5.1 % potential loss in alkaline medium. Co@PANI‐600 catalyst exhibits excellent OER performances as well as having enough kinetics to solve the sluggish rate of water oxidation. At 1.54 V, the solar driven water electrolysis demonstration supports the efficiency of new born electrocatalyst in solar to hydrogen conversion. These research findings confirm that Co@PANI‐600 can be used for large‐scale hydrogen generation at the lowest possible cost.

Efficient photocatalytic reduction of aqueous Cr (VI) by Zr4+ doped and polyaniline coupled SnS2 nanoflakes

• Zr-SnS 2 /PANI nanocomposites were synthesized and optimized for photocatalysis. • Higher activity than SnS 2 , Zr-SnS 2 , SnS 2 /PANI, and many other photocatalysts. • Zr 4+ doping and PANI coupling synergistically enhanced the photocatalysis of SnS 2 . • Factors affecting the photocatalytic reduction of Cr (VI) were investigated. • Zr-SnS 2 /PANI can effectively treat the Cr (VI)-containing electroplating solution. The synergistic Zr 4+ doping and PANI coupling were used to improve the photocatalytic activity of SnS 2 nanoflakes for the treatment of aqueous Cr (VI). The Zr-SnS 2 /PANI photocatalyst was prepared by a facile two-step method. The optimal Zr-SnS 2 /PANI-6% (with the Zr/Sn molar ratio of 1:8 and the PANI content of 6 wt%) exhibited dramatically higher photocatalytic activity toward Cr (VI) reduction than SnS 2 , Zr-SnS 2 , SnS 2 /PANI, and many previously reported SnS 2 -based and PANI-containing visible-light photocatalysts. Moreover, Zr-SnS 2 /PANI-6% showed outstanding performance in the photocatalytic treatment of Cr (VI)-containing electroplating solution. Based on the measured photo-electrochemical properties of the samples, the increased photocatalytic efficiency of Zr-SnS 2 /PANI-6% was mainly due to the synergistic effect induced by the smaller bandgap, higher charge transfer efficiency, and lower electron-hole recombination rate. Furthermore, the effects of coexisting cations and anions, photocatalyst amount, initial pH, Cr (VI) concentration, environmental atmosphere, and co-presence of 1,4-benzoquinone or K 2 S 2 O 8 on photocatalytic Cr (VI) reduction over Zr-SnS 2 /PANI-6% were investigated.