Polyaniline Titanium Research Articles

Distinguishable photocatalytic activity of nano polyaniline with quantum dots metal oxide as photocatalysts for photodegradation of Dianix blue dye and different industrial pollutants

Nanopolyaniline (PAN) polymers have recently been under active investigation as promising photocatalysts. In this work, a simple modified sol–gel method is used to make nano PAN polymers, and a chemical polymerization method is used to make nano polyaniline titanium dioxide quantum dots (PAN-TiQD) polymers as an active photocatalyst during the photodegradation of Dianix blue dye as an organic pollutant under xenon light. The traditional colloidal sol–gel method and the microwave-assisted hydrothermal method were used to make TiQD, which was then mixed with nanoPAN to make PAN-5 % TiQD (W/W) nanocomposites. Characterizations like XRD, FTIR, UV and visible diffuse reflectance spectra, TGA, surface area, EDX, and TEM were used to characterize the nanoPAN and PAN-TiQD that were made. Also, the photocatalytic activity of all synthesized polymers was investigated by the photodegradation process of Dianix blue dye as an organic hazardous pollutant in aqueous medium using a xenon photoreactor with an initial power of 75 W/Cm2. The effects of irradiation time and photocatalyst type on the photodegradation process efficiency of Dianix blue dye were examined. After 3 h of photodegradation processes, the photodegradation efficiency of PAN-TiQD reached 69 % compared to 36 % of nanoPAN due to the fact that it contains 5 % TiQD as a highly active catalyst, which reached 91 %. As an added value for this study, a significant contribution is the examination of eight hazardous industrial wastewater samples, which were assessed under direct sunlight and were in accordance with the KSA environmental permissible limit of 1000 ppm.Finally, the recycling processes in the presence of all synthesized catalysts were investigated and evaluated six times. The photodegradation rate of the recycling processes of Dianix blue dye was highly decreased in the presence of nano PAN than PAN-TiQD, while it had a low decreasing percentage in the case of TiQD. The recycling process using sunlight for industrial pollution samples was investigated at one of the KSA textile plants by using six synthetic catalysts and assessing COD and TOC values.

Polyaniline–Titanium Dioxide Heterostructures as Efficient Photocatalysts: A Review

This review paper focuses on present issues concerning the use of polyaniline–TiO2 heterostructures as potentially efficient photocatalysts. Conducting polymers such as polyaniline (PANI) are used in the preparation of heterojunction systems with metal oxides like titania to overcome their inherent limitations, e.g., their sole absorption of UV light and overly fast recombination of charge carriers. This review discusses preparation methods, the properties of resultant products and mechanistic aspects. An important part of this paper is its presentation of the major challenges and future perspectives of such photocatalytic materials.

Recycling and photodegradation processes of organic hazardous materials on polyaniline-titanium dioxide quantum dots catalyst

A photo-catalyst with conducting polymers doped with titanium dioxide, known as TiO2 quantum dots (TiO2 QDs), has a high efficiency for photocatalytic usage. The organic hue methyl orange was broken down in the current study using polyaniline (PANI) and polyaniline titanium dioxide quantum dots (PANI-TiO2 QDs) polymers. PANI and PANI-TiO2 QDs have been produced by chemical oxidative polymerization in an aqueous solution. By characterization of PANI-TiO2 QDs nanocomposites using ultraviolet–visible (UV–vis), Fourier transform infrared (FTIR), and X-ray powder diffraction (XRD), it was demonstrated that the chemical structure of polymer composites had not changed after being doped with TiO2 QDs. To determine the form, size, surface area, and thermal analyses of the produced PANI-TiO2 QDs samples, EDX, BET, and TGA were used. The photocatalytic activity of the PANI-TiO2 QDs in the photo-degradation of methyl orange dye as an organic hazardous chemical in an aqueous medium was assessed using a 50-watt xenon lamp light source and direct sunlight. PANI-TiO2 QDs demonstrated high photocatalytic properties, with a 93% efficiency, as opposed to 35% and 60.1%, respectively, for PANI and TiO2 QDs. When PANI, titanium dioxide quantum dots, and PANI-TiO2 QDs are present during the recycling processes in the presence of all created samples up to four times, the photo-degradation rate decreases by about 50.2%, 15.4%, and 17.4%, respectively.

Polyaniline-Titanium Dioxide- Bentonite Nanocomposite for Removing Heavy Metal and Dyes from Wastewater: A Short Review

Polyaniline-Titanium Dioxide- Bentonite Nanocomposite for Removing Heavy Metal and Dyes from Wastewater: A Short Review

Development of polyaniline – TiO2 nano composite films and its application in corrosion inhibition of oil pipelines

Oil and gas industries are the driving force of Oman’s economy and have a relatively diversified wealth among Gulf Cooperation Council Countries. Oil pipelines play an important role in transporting oil and gas from the wellheads to the processing facilities. Corrosion normally results in the deterioration of the pipe material with exposure to the surrounding environment and complete control of corrosion is difficult. Corrosion in oil transmission pipeline would be effectively addressed by introducing conventional corrosion control practices. Most of the conventional techniques are either less effective or too expensive in controlling the deterioration rate of the pipe materials. However, preventative measures may be taken to protect the metal surface from corrosion is a possible way to reduce corrosion. This research work aimed to develop a novel technique utilizing Polyaniline (PANI) and Titanium dioxide (TiO2) nanocomposites to assess its corrosion inhibition effect on mild steel. TiO2 was synthesized by sol-gel process. Polyaniline-Titanium dioxide (PANI/TiO2) nanocomposites were coated on mild steel specimen by dip coating technique. The coated specimen was subjected to stability studies at different environmental conditions and exposure time. The stable thin film coated specimen was employed in the corrosion inhibition studies at various processing environments. The characteristics of TiO2 nanoparticles and PANI-TiO2 thin films were analyzed using Fourier Transform Infra-Red Spectroscopy (FTIR), Energy Dispersive X-Ray analysis (EDX) and X-Ray Diffraction (XRD) and Dynamic Light scattering (DLS). Scanning Electron Microscopy (SEM) was used to visualize the surface morphology and micro structural characteristics of the preformed thin layer. Potentio dynamic test, Atmosphere test and Wet/Dry tests were carried out to investigate the corrosion behaviour of coated and uncoated specimen. The study demonstrates that the Polyaniline – TiO2 composite thin films fabricated using dip coating technique with minimum film thickness could be a feasible solution in controlling the corrosion in oil pipelines with good film stability, high durability, with a cost effective and environmentally friendly approach.

Titanium Dioxide (TiO2) Concentration-dependent Photovoltaic Cells Performance of PAni-TiO2 Nanocomposite

By optimizing the features of the photoactivated polyaniline-titanium dioxide (PAni-TiO2) nanocomposite layer, varied concentrations of TiO2 nanoparticles (NPs) inside PAni matrix were used to improve the performance of organic cells. In this work, polymer solar cells were designed using the FTO/(PAni- TiO2)/Ag combination. PAni-TiO2 films’ structural evolution, surface properties, optical and electrical characteristics have been studied. The XRD patterns showed that the crystallite size gradually decreases from 18.7 to 12.8 nm depending on the TiO2 NPs concentration in the PAni matrix. In addition, the surface of the highly concentrated films was rougher and more porous than it was for the pristine film. With varying concentrations of TiO2 NPs incorporated into the PAni structure, PAni- TiO2 based composite cells’ efficiency enhanced from 0.33 to 0.85%. This conclusion is mostly related to a structural shift accompanied by a high increase in roughness scales, that led to a reduction of reflected photons and, as a consequence, an increase in the creation of free carriers.

Langmuir-Blodgett monolayer of electrochemically synthesized PANI-TiO2 nanocomposites for MSG biosensor

Nanocomposites of polyaniline titanium oxide (PANI-TiO2) have been synthesized by employing the electrochemical technique and their monolayers were prepared on a pre-chemical treated indium tin oxide (ITO) surface through Langmuir-Blodgett (LB) process. The TEM images show the well dispersion of an average ∼ 5 nm diameter TiO2 particles in the film of PANI-TiO2 with ∼ 0.35 nm interatomic spacing of titanium atoms in the anatase crystalline plane (101). X-ray photoelectron (XPS) spectra of LB film of PANI-TiO2 also confirmed the presence of Ti atoms as a similar observation was also confirmed in energy dispersive X-ray analysis (EDX) analysis of the film surface. Electrochemical conductivity of the PANI-TiO2 LB films showed enhancement in peak current, and subsequent immobilization of monoclonal antibodies specific to l-glutamic acid was achieved. Differential pulse voltammetry (DPV) measurements showed a linear response in the peak current with MSG concentration varying from 1 nM to 500 µM and 1 µM to 250 µM in the electrolyte and tomato sauce, respectively. The detection sensitivity of the immunosensor was ∼ 37 mA/nM.

Photodegradation of textile pollutants by nanocomposite membranes of polyvinylidene fluoride integrated with polyaniline–titanium dioxide nanotubes

In this research article, the PVDF (polyvinylidene fluoride)–PANI (polyaniline)–titanium nanotube (TNT) based nanocomposite membranes were synthesised through phase inversion method. The composition and structural properties of nanocomposite membranes were characterised by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscope (SEM). The significant properties of synthesised membranes such as distribution of pore size, thermal properties, mechanical properties, and photocatalytic behaviour of membranes were also studied. The hydrophilic properties of the composite membranes increased with filler content (PANI-TNT) and results in improved pure water flux (484.8 ± 2.9 L/m2 h−1) compared to that (312.0 ± 1.91 L/m2 h−1) of the pure PVDF membrane. The pure PVDF and nanocomposite membrane were further analysed in terms of their filtration properties such as adsorption of dyes (methyl orange, Allura red) and UV self-cleaning properties. The newly developed nanocomposite membranes showed excellent pollutant removal efficiency (~90%). The synthesised nanocomposite membranes also showed photocatalytic activities due to the presence of TNTs, and adsorption of methyl orange (MO) reduces significantly with the UV light irradiations. The UV self-cleaning property of the composite membrane was further confirmed due to their high flux recovery ratio of about 94%. The results show that embedded PANI-TNT within nanocomposite was photo-catalytically active and degrade the dye molecules from the surface of the nano composite membrane.

High charge retention and optimization of polyaniline–titanium dioxide nanoparticles composite nanostructures for dominantly stable pseudocapacitive nature

Abstract This work is conducted with the aim of improving overall specific capacity of polyaniline with incorporation of minimum amount of TiO2 nanoparticles where the structure could facilitate an efficient access to electrolyte ions to the electrode surface and shorten the ion diffusion path. The paper presents low temperature (0 to 5OC) in-situ synthesis scheme for Polyaniline (PANI) with very small (%wt) varying amount of titanium dioxide nanoparticles (nTiO2) for high performance supercapacitive nanocomposite electrode materials. PANI-nTiO2 composites are synthesized via standard in-situ chemical oxidative polymerization of aniline monomer in the presence of Hydrochloric Acid (HCl) as a dopant and Ammonium per Sulphate (APS) as an oxidant. The electrochemical analysis is carried out in a two-electrode geometry system. The redox supercapacitor cells using nanocomposite electrode materials are fabricated with diluted 0.1 M Sulphuric Acid (H2SO4) electrolyte. The highest claimed capacitance ~813 F/g at current density 1 mA/cm2 is obtained for the sample PT5 composite electrode with 5 wt% nTiO2 invariably due to the presence of thinner PANI nanofibers. This PT5 based symmetric supercapacitor device exhibits a high specific energy ~ 16.8 Whkg−1 at the maximum specific power ~ 9.75 Wkg−1. The PT5 symmetric nanocomposite sample showed no decay of capacitance till 2000 current charge/discharge cycles at a current density of 1 mA/cm2 in a potential window of 0.8 V. The decay (813 Fg−1 to 743 Fg−1) in capacitive value can be considered almost negligible. The presence of nTiO2 in small%wt in PANI composite enhances the specific capacitance claimed significantly as compared to its electric double-layer supercapacitor counterpart and is comparable to the reports available in this area. There is still a lot of scope to utilize these high performance nano-composite electrode materials with non-acidic electrolytes.

Substantially Improved Na-Ion Storage Capability by Nanostructured Organic-Inorganic Polyaniline-TiO2 Composite Electrodes.

Developing sodium (Na)-ion batteries is highly appealing because they offer the potential to be made from raw materials, which hold the promise to be less expensive, less toxic, and at the same time more abundant compared to state-of-the-art lithium (Li)-ion batteries. In this work, the Na-ion storage capability of nanostructured organic–inorganic polyaniline (PANI) titanium dioxide (TiO2) composite electrodes is studied. Self-organized, carbon-coated, and oxygen-deficient anatase TiO2–x-C nanotubes (NTs) are fabricated by a facile one-step anodic oxidation process followed by annealing at high temperatures in an argon–acetylene mixture. Subsequent electropolymerization of a thin film of PANI results in the fabrication of highly conductive and well-ordered, nanostructured organic–inorganic polyaniline-TiO2 composite electrodes. As a result, the PANI-coated TiO2–x-C NT composite electrodes exhibit higher Na storage capacities, significantly better capacity retention, advanced rate capability, and better Coulombic efficiencies compared to PANI-coated Ti metal and uncoated TiO2–x-C NTs for all current rates (C-rates) investigated.

Structural analyses of polyaniline–titanium oxide composite for acetone detection

This study characterized the performance of polyaniline–titanium oxide (PANI–TiO2) composite to assess its use as potential acetone detector in semiconductor gas sensor. Aniline (ANI), which refers to a monomer, has been used for in situ chemical polymerization to produce polyaniline (PANI) and titanium oxide (TiO2) composite. PANI was varied in composition of 20, 30, and 40 wt% loading with TiO2. Inclusion of PANI in composite is meant to detect acetone at various concentrations (100–500 ppm) at selected operating temperatures (27, 35, 45, 55, and 65 °C). The results signified that the best structure of PANI loading in TiO2 is at 30 wt% due to the molecular structure for gas sensor. The sensitivity of PANI–TiO2 composite pellet for various acetone vapor concentrations had been optimum at 300 ppm with 7.9% sensitivity. The optimum operating temperature was 45 °C with 10.12% sensitivity. Structural characterizations via X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and Brunauer–Emmet–Teller were conducted to correlate with the sensor sensing performance. Indeed, the 30 wt% of PANI–TiO2 composite has the potential to detect 300 ppm of acetone and displayed exceptional agreement with outcomes retrieved at 45 °C detection temperature.

Spectral and thermal studies on polyaniline–titanium dioxide nanocomposites by inverted emulsion techniques

Inverted emulsion polymerization technique using benzoyl peroxide, as an initiator, was used to prepare conducting polyaniline (PANI)/nano titanium dioxide (TiO2) composites. Polyaniline ratio was varied between 10 and 90% based on the yield percentage. The prepared nanocomposites were analyzed further by Fourier-transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, and four probe conductivity. The FTIR spectrum of pure PANI and its composites with nano-TiO2 shows the vibrational bands due to benzenoid, quinoid ring stretching etc. Conductivity of pure polyaniline was observed to be 1.6 S cm−1 and upon the addition of nano-TiO2 the conductivity decreases. X-ray diffraction of PANI–nano TiO2 composites reveals that the crystalline nature of TiO2 is retained. TGA thermogram of nanocomposites monitored the thermal stability of pure PANI which improved by the addition of TiO2 in different ratios. SEM image reveal that nano-TiO2 particles are uniformly distributed in the PANI matrix.

Enhancement in alternating current conductivity of HCl doped polyaniline by modified titania

ABSTRACTTo enhance the alternating current (AC) conductivity of polyaniline (PANI), modified titanium dioxide (TiO2) prepared by one-step semi-solvothermal method is used to synthesize optimized polyaniline-titanium dioxide (PANI-TiO2) composite by in-situ polymerization method so as to form p-n heterojunction interface between them. The prepared samples were characterized by FTIR, XRD and SEM techniques. Nanostructure of the composite was confirmed from TEM technique. Increased conductivity of the composite compared to that of PANI due to interfacial interaction between PANI and TiO2 in it was confirmed from FTIR, XRD and SEM studies. Conduction in both PANI and the composite by hopping mechanism was confirmed by studying the power law behavior of their AC conductivity. High values of the real part of the complex dielectric constant and dielectric loss tangent at low frequency for both PANI and the composite were confirmed to be due to interfacial Maxwell-Wagner polarization. Increased conductivity of the composite as compared to that of pristine PANI was confirmed by a shift of the peak towards a relatively higher frequency in the plot of the imaginary part of the complex electric modulus with frequency.

Effect of mechanical mixing method of preparation of polyaniline-transition metal oxide composites on DC conductivity and humidity sensing response

In the present work, optimized polyaniline-titanium dioxide (PANI-TiO2) and polyaniline-yttrium oxide (PANI-Y2O3) composites were prepared by mechanical mixing of chemically synthesized PANI with TiO2 and Y2O3 transition metal oxides respectively. The Fourier transform infrared spectroscopy (FTIR) analysis confirmed relative decrease in depth of delocalization band of PANI in the composites as compared to that in PANI. The X-ray diffraction (XRD) studies confirmed decrease in degree of crystallinity and increase in inter-chain separation of PANI in the composites as compared to those of PANI. The scanning electron microscopy (SEM) images confirmed relatively more agglomerated and porous granular morphology of the composites as compared to that of PANI. Decrease in DC conductivity of the composites as compared to that of PANI confirmed experimentally and then supported theoretically by one dimensional variable ranging hopping (VRH) model. The PANI-TiO2 and PANI-Y2O3 composites, when studied for their humidity sensing performance, recorded remarkable maximum sensing response of 94 and 96% respectively at 97% RH as compared to 40% of PANI. The response and the recovery time of PANI-TiO2 composite were 95 and 122 s respectively and those of PANI-Y2O3 composite were 50 and 80 s respectively. Humidity sensing stability of the composites tested for a period of 1 month and confirmed.

CO gas sensitivity and its oxidation over TiO2 modified by PANI under UV irradiation at room temperature

A series of polyaniline–titanium dioxide (PANI/TiO2) nanocomposite film sensor were fabricated by an in-situ chemical oxidation polymerization of aniline at TiO2 (anatase) surface, and were evaluated the CO gas sensitivity under UV irradiation at room temperature. Although adding PANI into TiO2 seemed to weaken the photo-assisted conductivity of film sensor sample at N2 atmosphere, it enhanced the photo-assisted gas sensitivity to CO. Based on the chemical characterization results of PANI/TiO2 by FT-IR, Raman and XPS, it is proposed that the protonated N site in PANI chains (formed by TiO2 interacting with PANI) would promote the adsorption of CO, resulting in the more electrons from CO to PANI by the typical π–conjugated structures of benzenoid and quinonoid units and then to TiO2 by the hydrogen bonds (N⋯H⋯O) in the interface of PANI and TiO2. Moreover, the presence of H2O could enhance this photo-assisted gas sensitivity. Furthermore, the PANI/TiO2 powder sample also exhibited a higher activity of photocatalytic oxidizing CO than the pure TiO2 sample, indicating that the enhancement in the photo-assisted sensing response to CO would benefit the photocatalytic oxidation of CO over PANI/TiO2. This study not only provides a possible approach to develop a photo-assisted gas-sensitive material by introducing the structure of organic-inorganic hybrided nanocomposite, but also provides a possible method to estimate the photocatalytic activity of a semiconductor material by testing its photo-assisted sensitivity to the reactant gas.

Effect of polyaniline concentration on the photoconversion efficiency of nano-TiO2 based dye sensitized solar cells

Extensive research have been made in improving the dye sensitized solar cells (DSSC) performance by designing, tailoring and enhancing the photoconversion properties of the matrix. The approaches used are material synthesis, dye permutation combinations, use of natural extracts or using several sensitizers. The polymers are also being explored in this regards in their pristine or composite forms. Therefore, in this study an attempt is made to synthesize a mesoporous polyaniline–titanium dioxide (PANI–TiO2) nanocomposites with one pot synthesis approach at different concentrations of PANI (0.3–0.7 ml). Titanium isopropoxide was used as precursor for TiO2 with aniline and the material was synthesized at ice bath temperature. Morphological observations showed that the composite is a mesoporous material with tubular structure where TiO2 particles are seen entrapped in the polymer matrix and found that intercalation can be tailored with PANI concentration. Structural, functional and optical characterization indicate anatase phase of TiO2, with several functional bands that can help in dye interaction and broad absorption bands within visible region. The photocurrent-voltage response was measured with simulated light and source-meter. It is interesting to note that increasing PANI concentration enhances the mesoporous structure and hence increases the dye loading capacity and photoconductivity of the material. The efficiency increased by about 22 % with addition of 0.5 ml of PANI from 0.3 ml. The proposed study has indicated that such material have the potential to be used for DSSC fabrication with which the device performance can further be increased to a better levels.

Polyaniline-Titanium dioxide composite as humidity sensor at room temperature

Polyaniline-Titanium dioxide composite as humidity sensor at room temperature

Effect of nanostructured graphene oxide on electrochemical activity of its composite with polyaniline titanium dioxide

Graphene oxide (GO) significantly affects the electrochemical activity of its composite with polyanline titanium dioxide (TiO2). In this work various composites with different GO contents have been successfully synthesized by chemical method to compare not only their material properties but also electrochemical characteristics with each other. The results of an electrochemical impedance study showed that their electrochemical property has been improved due to the presence of GO in a composite matrix. The galvanodynamic polarization explained that among them the composite with GO/Ani ratio in the range of 1–14 exhibits a better performance compared to the other due to yielding a higher current desity (280 μA cm−2). The TEM and SEM images which presented the fibres of a composite bundle with the presence of PANi and TiO2 were examined by IR-spectra and x-ray diffraction, respectively.

Correction to “Route to High Surface Area, Mesoporosity of Polyaniline–Titanium Dioxide Nanocomposites via One Pot Synthesis for Energy Storage Applications”

Correction to “Route to High Surface Area, Mesoporosity of Polyaniline–Titanium Dioxide Nanocomposites via One Pot Synthesis for Energy Storage Applications”

Improving the electrochemical behavior of sustainable polyaniline titanium dioxide composite by intercalation of carbon nanotubes

AbstractPolyaniline titanium dioxide (PANi-TiO