PANI Nanorods Research Articles

Multifunctional electrochromic yarns for variable optical and thermal regulation

In this study, tungsten oxide and polyaniline hybrid films were deposited on the surface of stainless steel yarns by electrochemical deposition, and the electrochromic yarns with double electrochromic layer structure were formed. WO3 acts as a protective layer and binder to connect PANI nanorods, thereby improving electrochemical stability and electrochromic performance. The electrochromic yarns present five color changes in the voltage range of −0.4 V-1.1 V, the optical modulation of 59.98 %, the response time of 0.75 s, the coloration efficiency of 74.89 cm2/C, good electrochemical cycling stability (100 cycles without significant degeneration) and washing durability. At the same time, stable electrochromic behavior is still maintained in the bending state. The device based electrochromic yarns also has reversible multi-color variation, fast reaction time, and long-term stability. What's more, the device can be embroidered or woven into the fabric and designed into patterns of different colors. More color combinations can be achieved by adjusting the voltage. Finally, the fabric based on multifunction electrochromic yarns are used to study the thermal shielding performance. It can effectively block thermal radiation. These results indicate that the electrochromic yarn has promising potential for high-performance optical and thermal regulation applications. This research provides a prospective strategy for constructing multifunctional electronic devices in wearable application.

Preparation of sodium zinc phosphate/polyaniline nanocomposite for Cr(VI) and eriochrome black T adsorption from water

In this study, ultrasound physical mixing of polyaniline (PAni) and sodium zinc phosphate (NaZnP) materials resulted in the synthesis of a new nanocomposite (NaZnP/PAni). Samples were physicochemically characterized via different analytical techniques. The X-ray diffraction pattern indicated the synthesis of hydrated sodium zinc phosphate (Na6(ZnPO4)6.8 H2O) with an average crystallite size of 40.8 nm. After physical mixing with PAni, the crystallite size of the resulting composite was reduced to 36 nm. Scanning electron microscopy (SEM) revealed that the nanocomposite was formed by the deposition of NaZnP nanospheres over PAni nanorods. The adsorption efficiency of the composite was monitored using an azo dye (eriochrome black T (EB)) and hexavalent chromium (Cr(VI)). The optimization of the effects of operating parameters (pH, NaZnP/PAni dosage, starting pollutants concentration, and reaction time) on the removal efficiency were examined using the central composite design (CCD). The predicted removal efficiencies under the optimum conditions were 93 % and 98 % for EB and Cr(VI), respectively. The adsorption kinetics modeling reveals that the pseudo-second-order describes the uptake of Cr(VI) and EB. Equilibrium data fitted well with the Redlich-Peterson and Sips isotherm models. The highest retention capacity of NaZnP/PAni was 234 mg/g for EB and 231 mg/g for Cr(VI). Consequently, the developed NaZnP/PAni nanocomposite could be applied to remove heavy metals and dyes from wastewater with great efficiency.

3D Ti3C2TX@PANI-reduced graphene oxide hydrogel and defective reduced graphene oxide hydrogel as anode and cathode for high-energy asymmetric supercapacitor

The rational constructions of asymmetric supercapacitors (ASCs) by extending the operating potential window has been verified as an effective tactic to break through the energy density of the device. In this work, Ti3C2TX @polyaniline (PANI) heterostructure is successfully synthesized by uniformly depositing PANI nanorods onto the surface of Ti3C2TX nanosheets through polymer polymerization, then via a low-temperature hydrothermal graphene oxide (GO)-gelation process, Ti3C2TX @PANI is assembled into a three-dimensional (3D) porous hydrogel. The resultant Ti3C2TX @PANI-reduced graphene oxide (RGO) hydrogel exhibits a high specific capacitance of 617.84 F g−1 at 0.5 A g−1. Separately, a defective reduced graphene oxide (DRGO) hydrogel is prepared by a cost-effective cobalt-catalyzed gasification procedure, which shows a higher specific capacitance (237.62 F g−1 at 0.5 A g−1) than that of untreated RGO hydrogel (158 F g−1). Finally, Ti3C2TX @PANI-RGO and DRGO are used as anode and cathode to construct the Ti3C2TX @PANI-RGO//DRGO ASC device, which features a stable operating voltage (−1.6 to 0.2 V), an ultra-high energy density (269.18 Wh kg−1 at 527.72 W kg−1 and 77.90 Wh kg−1 at 12,409.04 W kg−1), and durable cycling property (retaining 92.52% capacitance after 10,000 cycles at 10 A g−1). This research emphasizes the extraordinary superiority of Ti3C2TX-based structures for the construction of high-energy ASCs.

Properties of mesoporous pani nanorods obtained by facil acid-free synthesis as a sorbent for methylene blue and indigo carmine removal

Properties of mesoporous pani nanorods obtained by facil acid-free synthesis as a sorbent for methylene blue and indigo carmine removal

Preparation of polyaniline nanorods/manganese dioxide nanoflowers core/shell nanostructure and investigation of electrochemical performances

A hierarchical polyaniline nanorod/manganese dioxide nanoflower (PANI/MnO2) core/shell nanostructure was successfully constructed through in situ polymerization, in which PANI nanorods work as the core and K-birnessite-type MnO2 act as the shell. The core/shell nanostructure effectively increases active surface areas and obviously decreases the ion transmission distance, which is conducive to the efficient contact and transfer of ions. The morphology, the chemical structure, and the crystal phase of PANI/MnO2 were measured by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Moreover, its supercapacitor behaviors were analyzed by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) tests, showing that this nanostructure exhibits better electrochemical activity and higher capacitance performance than pure PANI nanorods and pure MnO2. In 1.0 M Na2SO4 electrolyte solution, the specific capacitance of PANI/MnO2 is 215 F g−1 at 0.30 A g−1.

PANI/MoO3−x shell–core composites with enhanced rate and cycling performance for flexible solid-state supercapacitors and electrochromic applications

PANI/MoO3−x shell–core composites show enhanced electrochemical and electrochromic performance as a bi-functional electrode material for flexible solid-state supercapacitors, attributed to a synergistic effect from PANI nanorods and MoO3−x nanobelts.

Humidity enhanced ammonia sensing of porous polyaniline/tungsten disulfide nanocomposite film

A significant threat of poisonous and colorless ammonia (NH3) emission at low level to environmental protection and human health urgently necessitates sensitive NH3 detection. Meanwhile, low-powered gas sensing is quite favorable in the fields of wearable and portable devices with the ultimate target of battery-free operation. To achieve these goals, in this work we prepared a porous polyaniline/tungsten disulfide (PANI/WS2) nanocomposite film to detect ppm-level NH3 gas at room temperature (25 °C) under humid background atmosphere. The as-prepared PANI/WS2 sensor with 1.5 mg of WS2 loading exhibited a stronger response (1.25 vs. 1.02), better operation stability and accelerated response/recovery speeds toward 10 ppm NH3 at a relative humidity of 68 % (the optimal RH level) in comparison with PANI counterpart. Moreover, decent repeatability and NH3 selectivity were demonstrated. Noteworthy was that excess WS2 loading adversely weakened the sensor response. More WS2 incorporation induced wider aggregations of PANI nanorods acting as the supporting pillars within the porous composite film, which obviously strengthened film structure and then the operation robustness under humid atmosphere compared with pure PANI sensor. The presented design strategy by subtle optimization of operation RH and WS2 loading paves the avenue for further sub-ppm NH3 detection of PANI-related gas sensors in the aspects of high sensitivity and strong stability.

Three-dimensional Porous Graphene/Polyaniline Hybrids for High Performance Supercapacitor Electrodes

Graphene-based composites took extensive attraction as electrodes for supercacitors these years. Three-dimensional cross-linking porous graphene (3D rGO-m) was obtained by KOH activation to graphene modified by 1,2,4-triaminobenzene. 3D porous graphene/ polyaniline hybrids (3D rGO-m/PANI) was prepared by the in-situ chemical oxidative polymerization. The rGO-m are reconstructed from 2D to 3D porous structure after KOH activation. The PANI nanorod arrays are successfully decorated on the surface of the 3D porous graphene sheets. The specific capacitance of the 3D rGO-m/PANI hybrids reach 985 F/g at 0.5 A/g. The capacitance retention of 3D rGO-m/PANI maintains 90% of its initial capacity after 1000 cycles, while rGO-m/PANI only keeps 83% of its initial capacity, the cycling stability of both hybrids are higher than that of pure PANI (69%).

Engineering Active Sites of Polyaniline for AlCl2 + Storage in an Aluminum-Ion Battery.

The reversible capacity of AlCl4 - intercalation/de-intercalation in conventional cathodes of aluminum-ion batteries (AIBs) is difficult to improve due to the large size of AlCl4 - anions. Therefore, it is highly desirable to realize the intercalation/de-intercalation of smaller Al-based ions. Here, we fabricated polyaniline/single-walled carbon nanotubes (PANI/SWCNTs) composite films and protonated the PANI nanorods. The protonation endows PANI with more active sites and enhanced conductivity. Hyper self-protonated PANI (PANI(H+ )) exhibits reversible AlCl2 + intercalation/de-intercalation during the discharge/charge process. As a result, the discharge capacity of the Al/PANI(H+ ) battery is twice as high as that of the initial composite films. PANI(H+ )@SWCNT electrodes also have a stable cycling life with only 0.003 % capacity decay per cycle over 8000 cycles. Owing to the excellent mechanical properties, PANI(H+ )@SWCNT composite films can act as the electrodes of flexible AIBs.

Engineering Active Sites of Polyaniline for AlCl2+ Storage in an Aluminum‐Ion Battery

AbstractThe reversible capacity of AlCl4− intercalation/de‐intercalation in conventional cathodes of aluminum‐ion batteries (AIBs) is difficult to improve due to the large size of AlCl4− anions. Therefore, it is highly desirable to realize the intercalation/de‐intercalation of smaller Al‐based ions. Here, we fabricated polyaniline/single‐walled carbon nanotubes (PANI/SWCNTs) composite films and protonated the PANI nanorods. The protonation endows PANI with more active sites and enhanced conductivity. Hyper self‐protonated PANI (PANI(H+)) exhibits reversible AlCl2+ intercalation/de‐intercalation during the discharge/charge process. As a result, the discharge capacity of the Al/PANI(H+) battery is twice as high as that of the initial composite films. PANI(H+)@SWCNT electrodes also have a stable cycling life with only 0.003 % capacity decay per cycle over 8000 cycles. Owing to the excellent mechanical properties, PANI(H+)@SWCNT composite films can act as the electrodes of flexible AIBs.

Preparation of Slightly Crumpled Aminated Graphene Nanosheets for Honeycomb-Like Flexible Graphene/PANI Composite Film Electrode with Enhanced Capacitive Performance in Solid-State Supercapacitors.

Slightly crumpled aminated graphene nanosheets were prepared via the mild surface modification of graphene oxide (GO) nanosheets with p-phenylenediamine at room temperature to inhibit the restacking of graphene but avoid cross-linking during the solvothermal or microwave-assisted treatments, and then the honeycomb-like flexible graphene/polyaniline (PANI) composite film electrode, PANI@rPGO, was developed by the facile vacuum filtration and reduction. Owing to the slightly crumpled PGO nanosheets with surface amino groups, the honeycomb-like PANI@rPGO composite film, with a well-defined dispersion of PANI nanorods in the graphene-based matrix and the hierarchically porous structure, possessed superior electrochemical performance as a robust electrode in flexible solid-state supercapacitors (SSCs). The symmetric SSCs based on the PANI@rPGO electrode possessed a high capacitance of 564.5 F/g and 2015.2 mF/cm2 at 0.5 A/g (2.2 mA/cm2), superior cyclic life with retentions of 104.2 and 78.5% after 2000 and 5000 cycles at 3 A/g, as well as excellent flexibility. The mild one-pot preparation and the superior electrochemical performance make the designed PANI@rPGO composite film electrode a potential candidate for high-performance flexible SSCs.

Binary composites of strontium oxide/polyaniline for high performance supercapattery devices

The study divulges the innovative route to the synthesis of strontium oxide (SrO) nanorods integrated with polyaniline (SrO-PANI) by using physical blending method and utilized for high performance asymmetric supercapacitor. The synthesized nanocomposites (NCs) are initially characterized by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrochemical performance of the NCs is evaluated for energy storage applications. The results demonstrated that the SrO-PANI NCs yield a maximum specific capacity (Qs) of 258 C g−1 at current density of 0.8 A g−1 in three electrode assembly and exhibit better electrochemical stability as compared to PANI and SrO nanorods. Supercapattery device is fabricated by using SrO-PANI NCs. Results reveal that supercapattery device gives an improved energy density of 24 Wh kg−1 and the maximum power density is 2240 W kg−1. Furthermore, the fabricated supercapattery device demonstrated an excellent cyclic stability withholding the capacity of 114% after continues 3000 GCD cycles. The capacitive and diffusive contribution in total capacity of the device is further investigated by using Dunn's model. The advancement of these cost effective NCs are fairly suitable for proficient energy storage devices.

Fabrication of eco-friendly carbon microtubes @ nitrogen-doped reduced graphene oxide hybrid as an excellent carbonaceous scaffold to load MnO2 nanowall (PANI nanorod) as bifunctional material for high-performance supercapacitor and oxygen reduction reaction catalyst

Recently, with the concept of building a resource-conserving and environment-friendly society, the idea of developing green, sustainable and multifunctional materials has become increasingly urgent. So, how to explore more possible ways for efficient and sustainable utilization of biomass resources is very important. In this paper, a novel eco-friendly and sustainable 3D bifunctional carbon microtubes@nitrogen-doped reduced graphene oxide (CMT@N-RGO) hybrid based biomass material is firstly fabricated by combining dipping and chemical vapor deposition methods. Then the CMT@N-RGO hybrid is served as an excellent carbonaceous scaffold for constructing hierarchical hybrid with high-performance in energy storage and electrocatalysis. Finally, we have successfully prepared CMT@N-RGO/MnO2 and CMT@N-RGO/PANI hybrid with good supercapacitive and excellent oxygen reduction reaction (ORR). In short, the as-fabricated hybrid served as electrodes of supercapacitor present fast charge/discharge rate, excellent rate performance, and outstanding capacitance retention of 95% (93%) and high energy efficiency of 65–77% (61–72%) for both. In addition, the hybrid acted as an efficient electrocatalyst in the oxygen reduction reaction shows a larger positive onset potential of −0.12 V and half-wave potential of −0.21 V, which can be comparable to that of commercial Pt/C electrode. The improved capacitive and electrocatalytic properties are mainly attributed to the synergistic effects between the CMT and N-RGO/PANI (MnO2). In a word, these attractive results demonstrate that the 3D CMT@N-RGO/PANI (MnO2) hybrid are promising high-performance bifunctional material for supercapacitors and ORR catalyst. Hopefully, it can open up a versatile way for us to devise and manufacture more various multifunctional biomass-based material with outstanding electrochemical properties, excellent oxygen reduction reaction performance and other outstanding properties.

Heterogeneous nucleation promoting formation and enhancing microwave absorption properties in hierarchical sandwich-like polyaniline/graphene oxide induced by mechanical agitation

In this paper, polyaniline/graphene oxide composites were prepared by a one-step intercalation polymerization of aniline in the presence of GO layers under different mechanical agitation duration period, and the formation mechanism and microwave absorbing mechanism were investigated for an entire hierarchical sandwich-like structured polyaniline/graphene oxide composites. The morphology and structure were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, Brunauer-Emmett-Teller (BET) nitrogen sorption-desorption measurement and vector network analysis (VNA). The results revealed that mechanical agitation duration promoted the heterogeneous nucleation of aniline on graphene oxide layers and induced the formation of PANI-GO-PANI sandwich-like microstructure. The minimum reflection loss of entire sandwich-like structure reaches −28.12 dB at 5.675 GHz and an ultra-wide effective absorbing bandwidth (RL < −10 dB) over 13.175 GHz from 4.825 GHz to 18 GHz with the thickness varies from 2 mm to 5.5 mm, performing much better than pristine PANI and mixtures of PANI nanorods and sandwich-like structure. This paper reveals that constructing a hierarchical microstructure can be a promising method for developing novel microwave absorbing materials.

A scalable nano-engineering method to synthesize 3D-graphene-carbon nanotube hybrid fibers for supercapacitor applications

In this work, we describe a simple approach for the synthesis of three-dimensional graphene (3D-G) - carbon nanotube (CNT) hybrid fibers via Chemical Vapor Deposition (CVD). The obtained hybrid fiber was employed as a free-standing current collector in an electrochemical supercapacitor thus avoiding any conductive additives or metals. The amount of graphene synthesized on the CNT fiber and its properties have been easily tuned by different processing parameters, as described in the paper below. The fabricated fibers revealed a reasonable mechanical strength of 220.4 MPa and high electrical conductivity up to 649 Scm−1. They also showed excellent electrochemical properties and capacitance that was important for their energy storage application. Interconnected PANI nanorods were grown on these fibers by oxidation polymerization, and the resulted fibrous hybrid structures were used as electrodes to make supercapacitors. The created devices employed an ionic liquid gel electrolyte (PVDF-EMIMBF4) which had a voltage window of 3.2 V, thus increasing significantly the energy densities of the supercapacitors. The tested devices achieved a gravimetric energy density of 12.93 Wh/kg and a power density of 1350.25 W/kg at a current density of 1 A/g. They also demonstrated an areal energy density of 14.54 μWh/cm2 and a power density of 1.37 mW/cm2 at a current density of 1 mA/cm2.

Mixed Surfactant-Mediated Synthesis of Hierarchical PANI Nanorods for an Enzymatic Glucose Biosensor

The hierarchical nanoscale structure plays a crucial role in achieving excellent property, which can successfully be used in preparing tailor-made materials for sensing applications. These hierarch...

Synergistic effect of homogeneously dispersed PANI-TiN nanocomposites towards long-term anticorrosive performance of epoxy coatings

Novel polyaniline-titanium nitride (PANI-TiN) nanocomposites were synthesized by one step chemical oxidation polymerization at a low temperature and PANI-TiN/epoxy coatings with enhanced corrosion resistance were obtained based on the synergistic effect of TiN nanoparticles and PANI nanorods. PANI-TiN nanocomposites and resultant epoxy coatings were characterized by Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), Raman and X-ray photoelectron spectroscopy (XPS). Their anticorrosion performance in a 3.5 wt.% NaCl aqueous solution was investigated by the electrochemical impedance spectroscopy (EIS) and polarization curves. The results indicated that the corrosion resistance of PANI/epoxy coatings can be highly enhanced by introducing TiN nanoparticles to the PANI nanorods and the PANI-TiN/epoxy composite coating with 0.4 wt.% TiN (mass ratio to epoxy) exhibited the best corrosion protective performance, whose corrosion potential (Ecorr = −0.338 V) was positively shifted by 0.235 V compared with pure epoxy matrix (Ecorr = −0.573 V), and the corrosion current density was reduced by two orders of magnitude. The chemical structure of the rust layer and the anticorrosion mechanism were studied via X-ray diffraction analysis (XRD) and XPS. TiN nanoparticles showed a remarkably inhibiting effect on the agglomeration of PANI nanorods in epoxy coating. The corrosion resistance was attributed to the mixed mechanism of “passivation effect” of highly dispersed PANI and “labyrinth effect” of TiN nanoparticles.

Interfacial polymerized reduced graphene oxide covalently grafted polyaniline nanocomposites for high-performance electromagnetic wave absorber

The high-performance electromagnetic wave (EMW) absorption materials have great potential in both civil and military fields. A novel approach to prepare the reduced graphene oxide covalently grafted polyaniline (rGO-g-PANI) nanocomposites with the strong absorption intensity and broad bandwidth was employed in this paper. Specifically, the aniline monomers were bonded with the graphene oxide (GO) nanosheets via the nucleophilic ring-opening reaction of epoxy groups of GO. Coupling with the role of the reducer, rGO modified with aniline (rGO-An) was prepared. Subsequently, the rGO-g-PANI nanocomposites were synthesized by the interfacial polymerization, in which the rGO-An nanosheets served as the reactivity point for the interfacial polymerization of aniline, and PANI nanorods grew vertically on the rGO nanosheets. The calculated results of electromagnetic parameters suggest that the minimum reflection loss of the rGO-g-PANI nanocomposites can reach up to − 60.3 dB at the frequency of 11.1 GHz with the thickness of 2.86 mm, and the effective absorption bandwidth less than − 10 dB (90% microwave absorption) is as wide as 4.7 GHz (from 9.3 to 14 GHz) when the content of rGO-g-PANI in the paraffin matrix is 30 wt%. Compared with the rGO/PANI nanocomposites prepared via non-covalent absorption, the microwave absorption performance of the rGO-g-PANI nanocomposites has been greatly enhanced. The results in turn demonstrate that the covalent bonds between rGO nanosheets and PANI nanorods can facilitate the formation of the highly conductive networks, further promoting the EMW absorption.

Graphene oxide‐wrapped polyaniline nanorods for supercapacitor applications

This study depicts the chemical synthesis and supercapacitive behavior of nanocomposites of Polyaniline nanorods wrap with graphene oxide (PANI/GO). Synthesis of PANI/GO nanocomposites was carried out by in situ oxidative solution polymerization of aniline in the presence of Nitric acid, acting as a proton donor. The nanocomposites were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, X‐ray diffraction, Raman spectroscopy, thermal gravimetric analysis, contact angle analysis, cyclic voltammetry, galvanostatic charge–discharge test and electrochemical impedance spectroscopy. FESEM revealed the formation of PANI nanorods with the aspect ratio in the range of 3–5, while TEM revealed the wrapping of GO sheets on the PANI nanorods. Thermal stability showed decreasing trend while surface hydrophobicity was of increasing trend with GO concentration due to partial reduction of GO, as observed in Raman spectra. PANI/10 wt% GO (PANI/GO10) nanocomposite electrode showed highest specific capacitance of 276 F/g as compared with 180 F/g of Pure PANI. Cyclic stability of 80% was retained for PANI/GO10 nanocomposites after 500 cycles at a current density of 0.5A/g as compared with unstable PANI. The enhanced specific capacitance and good cyclic stability with increasing GO concentration revealed the good potential of PANI/GO nanocomposites for supercapacitor applications. POLYM. COMPOS., 40:E1716–E1724, 2019. © 2019 Society of Plastics Engineers

A Self-Powered Nanophotodetector System with High UV Photocurrent

We design and fabricate a relatively independent UV nanophotodetector system with p–n heterojunction that is composed of ZnO nanorods and PANI nanorods, which shows a surprised UV photocurrent. When the system is works, no any external power is applied except UV irradiation. In this system, two opposite p–n junctions are combined to form a special structure, one is regarded as a photocell and the other is as a p–n diode. Compared to the early structure of ZnO nanowires/PANI nanofibers, the novel structure with intersecting ZnO and PANI nanorods, in which p–n heterjunction has been added and the ZnO has been modified with 25 layers of PSS shows higher increase of UV photocurrent by nearly 10000 times (from ∼10–8 to ∼10–4 A). It is clear that this increase in order of magnitude provides an opportunity for the subsequent development of nanophotodetector that does not require any additional external power supply except UV light.