Phosphotungstic Acid Research Articles

Detection of antimicrobial impact on gram-negative bacterial cell envelope based on single-cell imaging by scanning electron microscopy

Rapid determination of drug efficacy against bacterial pathogens is needed to detect potentially resistant bacteria and allow for more rational use of antimicrobials. As an indicator of the antimicrobial effect for rapid detection, we found changes in image brightness in antimicrobial-affected bacteria by scanning electron microscopy (SEM). The cell envelopes of unaffected bacteria were stained with phosphotungstic acid (PTA), whereas the entire cells of affected bacteria were stained. Since tungsten density increases backscattered electron intensity, brighter bacterial images indicate lethal damage. We propose a simplified method for determining antimicrobial efficacy by detecting damage that occurs immediately after drug administration using tabletop SEM. This method enabled the visualization of microscopic deformations while distinguishing bacterial-cell-envelope damage on gram-negative bacteria due to image-brightness change. Escherichia coli, Acinetobacter baumannii, Enterobacter cloacae, Klebsiella pneumoniae, and Pseudomonas aeruginosa were exposed to imipenem and colistin, which affect the cell envelope through different mechanisms. Classification of single-cell images based on brightness was quantified for approximately 500 bacteria per sample, and the bright images predominated within 5 to 60 min of antimicrobial treatment, depending on the species. Using intracellular PTA staining and characteristic deformations as indicators, it was possible to determine the efficacy of antimicrobials in causing bacterial-cell-envelope damage.

Modification of Zr and HPW into MIL-101 with dipicolinic acid for effective removal of dibenzothiophene

Catalytic oxidation desulfurization, a high-tech technology for removing aromatics, has garnered widespread attention, and the key to this technology is developing a catalyst with high performance. In this study, MIL-101-[DA-Zr]3[PW], a composite of Zr(IV) and HPW active sites, was prepared by competitive coordination and electrostatic interactions based on MIL-101, dipicolinic acid, Zr(IV), and phosphotungstic acid (HPW). The obtained MIL-101-[DA-Zr]3[PW] was characterized in detail and applied to removal of dibenzothiophene (DBT) by catalytic oxidation. The MIL-101-[DA-Zr]3[PW] afforded a turnover number (TON) of 1.10 under optimized reaction conditions of O/S molar ratio of 4.0, catalyst dosage of 6.0 g.L−1, and reaction temperature of 55.0 °C Additionally, the study explored the co-catalytic mechanism between Zr(IV) and adjacent HPW, which found that effective synergistic catalysis could significantly improve the catalytic activity and the utilization rate of oxidant H2O2.

Heterogeneous phosphotungstate catalyst mediated efficient alcoholysis of furfuryl alcohol into long-chain levulinates

The synthesis of alternative fuels from biomass has emerged to be a vital strategy to maintain sustainable development. Long-chain levulinate esters (LEs) are a class of good biofuel candidates because they have similar structures to biodiesels and superior heating values. The synthesis of long-chain LEs with effective heterogeneous catalysts has always been challenging. In this work, a few heterogeneous phosphotungstate catalysts were facilely prepared, among which the V3+ exchanged phosphotungstic acid catalyst (VPW) was the most active for the alcoholysis of furfuryl alcohol (FA) and 1-hexanol into 1-hexyl levulinate (HL). A maximum HL yield of 63% was achieved at 180 °C. The VPW catalyst could be reused without obvious decrement of activity. The system was also applicable to the alcoholysis of FA with other hexanols and 1-octanol into various long-chain LEs.

Shuttling-free redox electrolyte locks proton-conductive polyoxometalates in porous carbon for high-performance pseudocapacitors

Redox electrolytes are highly attractive to bring conventional carbon-based supercapacitors the additional pseudocapacitance; however, shuttling of redox species remains a severe issue restricting the potential applications of redox electrolytes. Here, we report a new phosphotungstic acid-containing redox electrolyte for carbon-based supercapacitors, which shows the shuttling-free feature by locking the polyoxometalate mediators in the porous carbon electrode. Impressively, the porous carbon electrode affords a remarkable specific capacitance of 885.7 F g−1 at 5 mV s−1 in the phosphotungstic acid-added electrolyte, triple that in the additive-free H2SO4 electrolyte (290.2 F g−1). Profiting from the unique Grotthuss proton conduction of phosphotungstic acid, the porous carbon electrode achieves the dramatic rate capability in our redox electrolyte (i.e., 567.7 F g−1 at 200 mV s−1). Moreover, the assembled supercapacitor device affords a specific energy of 52.3 Wh kg−1 and long-term cycling stability (93.7% over 5000 cycles). This study highlights the superiority of the polyoxometalate additive for redox electrolytes in developing advanced supercapacitors integrating high energy density, excellent rate performance, and electrochemical durability.

Development of a method to investigate strain distribution across the cartilage-bone interface in guinea pig model of spontaneous osteoarthritis using lab-based contrast enhanced X-ray-computed tomography and digital volume correlation

ObjectiveStrain changes at the cartilage-bone interface play a crucial role in osteoarthritis (OA) development. Contrast-Enhanced X-ray Computed Tomography (CECT) and Digital Volume Correlation (DVC) can measure 3D strain changes at the osteochondral interface. Using lab-based CT systems it is often difficult to visualise soft tissues such as articular cartilage without staining to enhance contrast. Contrast-Enhancing Staining Agents (CESAs), such as Phosphotungstic Acid (PTA) in 70% ethanol, can cause tissue shrinkage and alter tissue mechanics. The aims of this study were, firstly, to assess changes to the mechanical properties of osteochondral tissue after staining with a PTA/PBS solution, and secondly, to visualise articular cartilage during loading and with CECT imaging in order to compare strain across the interface in both healthy and OA joints using DVC. DesignNanoindentation was used to assess changes to mechanical properties in articular cartilage and subchondral bone before and after staining. Hindlimbs from Dunkin-Hartley guinea pigs were stained with 1% PTA/PBS at room temperature for 6 days. Two consecutive CECT datasets were acquired for DVC error analysis. In-situ compression with a load corresponding to 2x body weight was applied, the specimen was re-imaged, and DVC was performed between the pre- and post-load tomograms. ResultsNanoindentation before and after PTA/PBS staining showed similar cartilage stiffness (p < 0.05), however, staining significantly decreased the stiffness of subchondral bone (∼9-fold; p = 0.0012). In severe OA specimens, third principal/compressive (εp3) strain was 141.7% higher and shear strain (γ) was 98.2% higher in tibial articular cartilage compared to non-OA (2 – month) specimens. A 23.1% increase in third principal stain strain and a 54.5% significant increase in the shear (γ) strain (p = 0.0027) was transferred into the mineralised regions of calcified cartilage and subchondral bone in severe OA specimens. ConclusionsThese results indicate the suitability of PTA in PBS as a contrast agent for the visualisation of cartilage during CECT imaging and allowed DVC computation of strain across the cartilage-bone interface. However, further research is needed to address the reduction in stiffness of subchondral bone after incubation in PBS.

Interfacial Engineering of Block Copolymer Nanostructures: Morphology and Solvent Stability.

Interfacial engineering is a critical pathway for modulating the self-assembled nanostructures of block copolymers (BCPs) during solvent exchange. Herein, we demonstrated the generation of different stacked lamellae of polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) nanostructures during solvent exchange by using phosphotungstic acid (PTA) or PTA/NaCl aqueous solution as the nonsolvent. The participation of PTA in the confined microphase separation of PS-b-P2VP in droplets increases the volume fraction of P2VP and decreases the tension at the oil/water interface. Moreover, the addition of NaCl to the PTA solution can further increase the surface coverage of P2VP/PTA on droplets. All factors impact the morphology of assembled BCP nanostructures. In the presence of PTA, ellipsoidal particles composed of alternatively stacked lamellae of PS and P2VP were formed (named BP), whereas, in the coexistence of PTA and NaCl, they changed to stacked disks with PS-core-P2VP-shell (called BPN). The different structures of assembled particles induce their different stabilities in solvents and different dissociation conditions as well. The dissociation of BP particles was easy because PS chains were only entangled together which can be swollen in toluene or chloroform. However, the dissociation of BPN was hard, requiring an organic base in hot ethanol. The structural difference in BP and BPN particles further extended to their dissociated disks, which makes the cargo (like R6G) loaded on these disks to show a different stability in acetone. This study demonstrated that a subtle structural change can greatly affect their properties.

Highly active sulfonic ionic liquid modified heteropoly acid composite catalysts for efficient production of ethyl palmitate

Highly active inorganic-organic composite catalysts were synthesized by incorporating Keggin-type tungstophosphoric acid (H3PW12O40; HPW) with SO3H-functionalized ionic liquids (SFILs), which were prepared by integrating chloromethylated polystyrene (CP) resin, piperazine (PI) and 1.3-propane sultone, as primary sources. The [CPPI-SO3H]nH3−nPW12O40 (n = 1.0–3.0) catalysts were characterized by XPS, SEM, FT-IR, XRD, TG-DTA, TEM, and solid-state 31P MAS NMR. These HPW-SFIL composite catalysts were found to be highly stable and possess ultra-strong Brønsted acidity, desirable self-separation properties, and catalyst reuse for production of biodiesels through esterification of palmitic acid (PA) and ethanol (EtOH). On the basis of the Box-Behnken design (BBD), further process optimization using response surface methodology (RSM) over the [CPPI-SO3H]2.0H1.0PW12O40 catalyst led to the optimized experimental conditions: EtOH/PA = 7.7 mol/mol, catalyst amount = 4.4 wt%, reaction time = 2.5 h, reaction temperature = 363 K, accompanied by an ethyl palmitate yield of 97.2%, in excellent agreement with the predicted value. The catalyst was highly stable, retaining a 94.7% yield after six consecutive running cycles. Moreover, a kinetic study performed under optimal reaction conditions revealed an apparent reaction order of 1.40 and an active energy of 14.80 kJ mol−1.

Polydopamine-coated polyimide nanofiber to anchor HPW and construct the pocket-like composite membrane with excellent proton conductivity and stability

Solid heteropolyacids with high intrinsic proton conductivity, like phosphotungstic acid (HPW), were added to further enhance the proton conductivity of sulfonated poly ether ketone (SPEEK). The great solubility of solid acid within water, however, would produce a dramatic decline in stability and durability. In this study, we utilized polydopamine (PDA) coated polyimide (PI) nanofiber to form the acid-base pair between PDA@PI nanofiber and HPW/SPEEK to anchor the HPW. Additionally, a pocket was constructed in the sandwich-structure PDA@PI/SPEEK + HPW membrane to help better anchor the HPW. After 6 weeks of durability treatment during 60 °C and 100% RH, proton conductivity of PDA@PI/SPEEK + HPW-20 was 163.5 mS cm−1, which was only 23.0% lower than that of the initial state. By sharp contrast, it was 55.2% lower than the initial state for pristine SPEEK. And its swelling ratio is only 54% compared with 128% of pristine SPEEK under the same condition. We first revealed and investigated the acid-base pair created by PDA@PI and HPW/SPEEK, which was beneficial for proton conductivity and durability. This pocket-like PDA@PI/SPEEK + HPW membrane would inspire a wide application in PEM among excellent proton conductivity, better stability, with endurance.

Dehydration of bioethanol over phosphotungstic acid immobilized onto nanoporous activated carbons: thermodesorption and catalytic studies

Phosphotungstic acid (PTA) was immobilized onto the porous structures of three nanoporous activated carbons (NACs), including oxidized, thermally treated, and pristine NACs. The PTA-NAC catalysts with different oxygen-containing functional groups on the carbon surface were obtained. The prepared catalysts can catalyze the reaction of bioethanol dehydration; they stimulate the formation of diethyl ether and ethylene. These catalysts showed high diethyl ether yields of up to 65% and excellent selectivities of up to 93% at 130–160 °С. The conversion of bioethanol to ethylene increased with increasing reaction temperature, and the ethylene yield reached almost 100% with about 100% selectivity at 190–220 °С.

Construction of heteropolyacid-anchored magnetic g-C3N4/Fe3O4@polyindole hybrids for efficient photocatalytic destruction of methyl orange and bacteria

Given the treatment of wastewater contaminated with organic dyes and bacteria, it is essential to fabricate high-performance, eco-friendly, and cost-effective photocatalytic materials. Herein, a new separatable and efficient organic–inorganic hybrid composite of tungstophosphoric acid(TPA) anchored by conducting polyindole (PID) onto magnetic graphitic carbon nitride (g-C3N4) was synthesized and used for photocatalytic degradation of methyl orange (MO) and gram-negative bacteria (P. aeruginosa) in the presence of visible LED illumination. The obtained g-C3N4/Fe3O4@PID-TPA photocatalyst was characterized by XRD, VSM, FESEM, EDX, TEM, BET surface area, DRS, PL, and FTIR methods. The g-C3N4/Fe3O4@PID-TPA catalyst (0.1 g/l catalyst dose) revealed high destruction activity (97.5%) for MO within 70 min. Due to the presence of controllable electronic structured g-C3N4, conductive PID polymer, and highly redox property of TPA heteropolyacid, boosted degradation activity was achieved by the g-C3N4/Fe3O4@PID-TPA heterostructure. Besides, the magnetic g-C3N4/Fe3O4@PID-TPA catalysts could be recycled five times without reduction in their photocatalytic performances. The g-C3N4/Fe3O4@PID-TPA catalyst demonstrates extraordinary antibacterial activity against P. aeruginosa (94.49%) at low g-C3N4/Fe3O4@PID-TPA dose. Besides, the antibacterial mechanism showed that the synergistic performance between g-C3N4/Fe3O4@PID and TPA harms the cell membranes, improves the levels of oxidative stress, and ultimately kills of P. aeruginosa. Also, the cytotoxic effect of g-C3N4/Fe3O4@PID-TPA catalyst was assessed in vitro by a MTT assay (achieving 25% to 29 % reduction in the colorectal carcinoma HCT116 cell viability). This work introduces a new outlook on developing organic–inorganic composite as photocatalysts based on heteropolyacids that serve multiple functions, particularly for environmental applications.

Synthesis of Fuel Additives via Esterification of Succinic Acid over a Sustainable Catalyst Comprising 12-Tungstophosphoric Acid Anchored to Zeolite HY

Synthesis of Fuel Additives via Esterification of Succinic Acid over a Sustainable Catalyst Comprising 12-Tungstophosphoric Acid Anchored to Zeolite HY

Encapsulation of phosphotungstic acid into UiO-66-(OH)2 for synergistic and rapid photocatalytic degradation of organic pollutants

PW12@ UiO-66-(OH)2 crystal was successfully fabricated by selecting UiO-66-(OH)2 as host matrix and encapsulating phosphotungstic acid (H3PW12O40, PW12) into its cage via one-pot synthesis. Characterization with FT-IR, PXRD, EDS and XPS confirmed that both the Keggin structure of PW12 and crystal structure of UiO-66-(OH)2 maintained well in the composite. The PW12@ UiO-66-(OH)2 can act as a photocatalyst to rapidly degrade organic pollutants in aqueous solution. UiO-66-(OH)2 was not only a carrier of PW12, but also an electron donor for the photocatalytic system. Due to the synergistic effect of PW12 and UiO-66-(OH)2, the degradation rate of methyl orange (MO) with PW12@ UiO-66-(OH)2 (90.42%) was greatly enhanced compared with using PW12 (28.25%) and UiO-66-(OH)2 (39.88%). Benefiting from the perfect size matching of PW12 and UiO-66-(OH)2, PW12@ UiO-66-(OH)2 exhibited satisfactory stability and reuse effect. This work will provide a new insight into the development of MOF-based composite photocatalysts to remove organic pollutants from wastewater.

Gene expression detection in developing mouse tissue using in situ hybridization and µCT imaging

High resolution and noninvasiveness have made soft-tissue X-ray microtomography (µCT) a widely applicable three-dimensional (3D) imaging method in studies of morphology and development. However, scarcity of molecular probes to visualize gene activity with µCT has remained a challenge. Here, we apply horseradish peroxidase-assisted reduction of silver and catalytic gold enhancement of the silver deposit to insitu hybridization in order to detect gene expression in developing tissues with µCT (here called GECT, gene expression CT). We show that GECT detects expression patterns of collagen type II alpha 1and sonic hedgehogin developing mouse tissues comparably with an alkaline phosphatase-based detection method. After detection, expression patterns are visualized with laboratory µCT, demonstrating that GECT is compatible with varying levels of gene expression and varying sizes of expression regions. Additionally, we show that the method is compatible with prior phosphotungstic acid staining, a conventional contrast staining approach in µCT imaging of soft tissues. Overall, GECT is a method that can be integrated with existing laboratory routines to obtain spatially accurate 3D detection of gene expression.

Synthesis of Phosphotungstic acid/S-doped g-C3N4 Photocatalyst and Its Photocatalytic Degradation of Organic Pollutants in Aqueous Solutions

The S-doped g-C3N4 (SCN) was prepared by thermal condensation method using thiourea as a precursor, and then the phosphotungstic acid (PTA)/SCN composite photocatalytic material was prepared by reflux adsorption method. The photocatalytic degradation experiments of Rhodamine B showed that SCN20 had the highest photocatalytic degradation rate (74 %), which was 1.9 times and 3.5 times higher than that of PTA (39 %) and SCN (21 %), respectively. The photocatalytic degradation rate of SCN20 was increased by 5 times compared to that of SCN, indicating that the photocatalytic degradation performance of the composite material was significantly improved. The photocatalytic degradation mechanism study revealed that O2- was the main active species in the photocatalytic degradation of Rhodamine B, and the addition of PTA helped the effective separation of electrons-hole and improved the photocatalytic degradation rate. Our PTA/SCN is proposed as an environmental safety tool due to several advantages, such as low cost, convenient preparation, and efficient photocatalytic degradation of Rhodamine B.

Structural regulatory mechanism of phosphotungstate acid decorated graphene oxide quantum dots-chitosan aerogel and its application in ciprofloxacin degradation

Chitosan modified AGQD (amine modified graphene oxide quantum dots) and then combined with H3PW12O40 to obtain CSx@AGQD-HPW12 via facile process and applied for CIP removal through pre-adsorption and photocatalytic processes. The application of chitosan could regulate the morphology and photoelectric properties effectively. CS0.5@AGQD-HPW12 was found to have the optimal CIP removal performance among all the products, the corresponding adsorption removal efficiency and pre-adsorption photocatalysis process were 72.1 % and 98.8 %, respectively. Results of toxicity assessment confirmed photocatalytic degradation process could mitigate the ecotoxicity of CIP effectively. The optimal TOC (total organic carbon) removal efficiency was about 52.1 %. Possible pathways for CIP degradation and reaction mechanism were proposed based on the results of intermediates analysis and trapping experiments. This demonstrated a novel approach to chitosan application and an eco-friendly way to remove CIP by adsorption-photocatalysis process.

Polyoxometalate Archetype-Boosted Stability and Charge Storage of 2D Graphene Nanosheets

In this study, the potential of impregnation of phosphotungstic acid (PTA), a polyoxometalate in enhancing specific capacitance (C sp) and diminishing the well-known restacking phenomenon of graphene nanosheets was explored. Graphene nanosheets were prepared chemically from graphite powder through the formation of graphene oxide (GO) and then the subsequent reduction of GO to the reduced GO (rGO). Impregnation of PTA in rGO-PTA (rGP) composites was carried out by simply dispersing rGO and PTA derived from tungstic acid. Scanning electron microscopy, X-ray diffraction analysis, UV–vis reflectance spectroscopy, and Fourier-transform infrared spectroscopy were used to analyze the elemental composition, microstates, and morphology of the composites. The charge-storing capacity and stability of the prepared rGP composites casted on a graphite electrode were examined with cyclic voltammetric, chronopotentiometric, and electrochemical impedance techniques. The effect of ions on the charging capacity of the electrodes was verified using electrolytes with different ion sizes. About 100% enhancement of C sp of rGO with 87% capacitance retention for 2000 charging-discharging cycles was achieved by impregnating rGP composites with only 1% PTA.

Production of Levulinic Acid from Chitosan in Different Solvent Mediums Using Tungstophosphoric Acid as Catalyst

Bu çalışmada kitosan ve glukozun farklı çözücü ortamlarında belirli sıcaklık ve sürede tungstofosforik asit katalizörlüğünde tek basamakta hidrolizi ve levulinik aside dönüşümleri incelenmiştir. Katalitik dönüşüm prosesinde kütlece 1:5 oranında (yardımcı çözücü-su) sulu ortama eklenen γ-valerolakton, kitosanın levulinik aside dönüşüm verimini değiştirmezken, glukoz dönüşüm verimini yaklaşık iki katına çıkarmıştır. Sulu ortama aynı oranda 1 butil 3 metilimidazolyum hidrojensülfat ilavesinde ise hem kitosan hem de glukoz dönüşümlerinde levulinik asit verimi sırasıyla %3,7 ve %22,7’ye ulaşmıştır. Kitosanın su/1 butil-3-metilimidazolyum hidrojensülfat ortamında dönüşümü sonrası toplam indirgen şeker miktarı ve katı atığın FT-IR spektrumu incelendiğinde iyonik sıvının asidik karakterinin hidroliz ve dönüşüm üzerinde etkili olduğu görülmektedir. Katalizörsüz sulu ortamda biyokütle dönüşümünde levulinik asit oluşmazken, tungstofosforik asit kullanıldığında kitosandan %3,1, glukozdan ise %7,0 verimle levulinik asit elde edilmiştir.

CONTRAST-ENHANCED MICROTOMOGRAPHY FOR VOLUMETRIC ANALYSIS OF MICROSTRUCTURE IN LIGAMENTS AND TENDONS

Tendons and ligaments play an important role to ensure mobility and stability. To correctly understand the characteristics of these fibrous collagenous connective tissues, it is fundamental to highlight their 3D microstructure. In this study a microtomography (microCT) system was used to acquire human hamstring tendons after performing specific preparations to enhance image contrast. Specifically, samples were treated either through chemical dehydration or by 2% of phosphotungstic acid ([Formula: see text]) in water ([Formula: see text]) or in 70% ethanol ([Formula: see text]) solution. Acquired images were elaborated using dedicated techniques based on 3D Hessian multiscale filter so as to highlight the fibrous structure and identify specific geometric features. For any strategy of sample preparation, the proposed approach resulted to be adequate for identifying fascicle features, thus obtaining structures with diameter in the range of 100–600 [Formula: see text] and proper longitudinal alignment. In conclusion, a novel contrast enhancement microCT protocol was designed and preliminarily validated for the microstructural analysis of fibrous tissues.

Solid-State Characterization of Heteropolyacid-Phyllosilicate Complexes: Structural, Morphological and Thermal Properties

We have previously described the complex formation from a synthetic smectite clay, Sumecton SA (SSA), and the heteropolyacid (HPA), 12-phosphotungstic acid (PTA). Three new synthetic layered aluminosilicate clays of the smectite- [Lucentite SWN (SWN)] and (fluoro)mica-type [Tetrasilicic mica (TSM); Somasif ME100, (SME)] have been self-assembled with PTA, at a specific PTA-clay weight ratio of 5. New protogenic inorganic complexes have been prepared for the future fabrication of proton exchange membrane for fuel cell devices (PEMFC). Complex formation, thermal and structural properties of PTA-phyllosilicate complexes have been investigated using EDX, XRD, SEM, and DRIFT. EDX indicates that complexes incorporate a substantial amount of PTA (50-60% w/w) and that a moderate depletion of Mg2+ ions from octahedral layers of micas clays occurs during the process compared to smectite ones. In contrast, a significant amount of F is removed from the octahedral framework of the mica clays. DRIFT experiments indicate that the Keggin structure is preserved within all complexes and that complex formation predominantly involves the external oxygen (W-Od) of PTA. According to Patterson functions, coherence lengths - which reflect for the virgin clays the extent of the longitudinal platelet stacking (Lc) - of the two smectite clays (Lc ~25 &amp;Aring;) are significantly lower than for their analogous of the mica type (Lc = 180-225 &amp;Aring;). Clays in complexes are characterized by the loss of in-plane organization but are still partially ordered. The nature of the order is still speculative but could be related to the formation of a new inorganic PTA species formed during the complex formation. Compared to the virgin clays, the order of smectite complexes is maintained in the same range (Lc = 27-42 &amp;Aring;) while for mica complexes, coherence lengths are dramatically reduced to ~ 60 &amp;Aring;. All PTA-activated complexes contain a substantial amount of amorphous silica, which tends to increase when heated at temperatures above 280 oC. However, the Keggin structure within the complexes is at least stable up to 280 oC and even, for the most robust TSM complex, up to 450 oC.

Fabrication of hybrid polyaniline – Polyoxometalate decorated with ZrO2 ternary nanocomposites with excellent visible light driven photocatalytic performance

The significant environmental concerns need the extensive fabrication and design of efficient visible light responsive photocatalysts materials. The objective of this research is to develop a highly efficient ternary polyaniline – phosphotungstic acid @ZrO2 nanohybrid photocatalyst for use in visible light. polyaniline – phosphotungstic acid @ZrO2 nanohybrids were successfully synthesized by chemical oxidative polymerization method and characterized. The XRD analysis confirms the formation of monoclinic zirconia phase crystalline polymer while HR-SEM and HR-TEM results reveals that polymers were grown on the surface of Phosphotungstic Acid-Zirconia and contributes to visible light absorption property. The photocatalytic activity of Polyaniline (PANI)/Phosphotungstic acid (PTA)-Zirconia (ZrO2) nanohybrids was studied using methylene blue (MB) dye, p-Nitrophenol (PNP), 2, 4-dichlorophenoxyaceticacid (2, 4-D) as toxic pollutants. It is found that, PANI/PTA-ZrO2 (3:1) shows enhanced photocatalytic activity.