Chemical Oxidative Polymerization Research Articles

Optimised and percolated nanocomposite of polyaniline/tungstic anhydride modified electrode implemented in Vanadium redox flow battery

In order to make vanadium redox flow batteries (VRFB) economically viable on a large scale, it is crucial to create graphite-based electrode nanomaterials with an excellent performance. In this research work, we synthesized the various percentage nanocomposites of polyaniline (PANI)/nano-tungsten oxide (NTO) by in situ chemical oxidative polymerization method. The impact of crystal phases, elements present in nanocomposites, thermal stability, surface analysis, and morphological factors were studied. We investigated electrochemical behavior such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel studies for PANI and NTO and prepared nanocomposites (NPATO) with different proportions sprayed over graphite felt (GF). Characterization analysis was used to examine the impact of various NTO loading concentrations on the PANI, and an ideal best percolated sample NPATO20/GF (3 mg cm−2) was inserted as a positive electrode in the cell stack to examine the charge–discharge cycles. At 60 mA cm−2 current density, their coulombic (η C), voltaic (η V), and energy (η E) efficiencies are outstanding. The concentration of 3 mg cm−2 nanoparticles on GF provided sufficient availability of active sites for electrochemical reactions, resulting in an increased electrochemical reaction. It has been proven that this work creates an affordable and efficient method for the forthcoming VRFBs.

Poly 2-chloroaniline/TiO2 quantum dots for solar and photocatalytic processes of Congo Red dye and industrial wastewater

This study investigates the synthesis and characterization of a poly 2-chloroaniline (PCl-AN)/TiO2 quantum dots (TQD) composite for photocatalytic degradation of Congo Red dye and industrial wastewater treatment. PCl-AN was synthesized via chemical oxidative polymerization of 2-chloroaniline (80 mmol) using ammonium persulfate (80 mmol) as an oxidant. TQD was prepared by a hydrothermal method using 18 mL of titanium tetrachloride and 45 mL of methanol at 80 °C for 24 h. The (PCl-AN)/TQD composite with 8 wt% TQD was fabricated by in-situ polymerization. Characterization techniques including XRD, FTIR, UV–vis, TGA, EDX, and TEM were employed. XRD revealed PCl-AN particle size of 29–40 nm and TQD sizes of 3.1–4.8 nm. TEM showed core-shell (PCl-AN)/TQD structures of 26–30 nm. The band gaps were 3.33 eV (PCl-AN), 2.17 eV (TQD), and 2.30 eV ((PCl-AN)/TQD). Photocatalytic tests using a 150 W xenon lamp (100 mW/cm2, 200–1100 nm) showed (PCl-AN)/TQD achieved 93.56 % Congo Red degradation in 120 mins, outperforming PCl-AN (51.69 %) and TQD (80.96 %). After 5 recycles, degradation rates decreased by 34.32 % (PCl-AN), 18.57 % (TQD), and 26.75 % ((PCl-AN)/TQD). For industrial wastewater with initial COD 5230–7150 ppm, (PCl-AN)/TQD reduced COD to 745–1230 ppm, meeting the <1000 ppm limit. The (PCl-AN)/TQD composite demonstrates promising photocatalytic performance for environmental remediation.

Adsorptive capacity of PANI/Bi2O3 composite through isotherm and kinetics studies on alizarin red

Adsorption offers numerous advantages for eliminating organic pollutants such as dyes, making it a valuable method for water treatment. Polyaniline/Bi2O3 (PANI/Bi2O3) nanocomposite is synthesized from aniline by the chemical oxidative polymerization method. The sample shows a high positive surface charge density as seen from zeta potential analysis. X-ray Diffraction analysis, FTIR analysis, UV–vis spectroscopy technique, thermogravimetric analysis, BET N2 Adsorption-desorption analysis, DLS, and zeta potential analysis are the tools employed to characterize the PANI/Bi2O3 nanocomposite. The impact of PANI/Bi2O3 on the outcome of adsorption is confirmed by comparing the composite with pristine Bi2O3 and PANI. The effect of various factors like time, temperature, initial dye concentration, and varying pH on the adsorption efficiency is studied. A maximum adsorption efficiency of 95 % is observed when 100 mg of PANI/Bi2O3 nanocomposite is utilized for a duration of 100 min. The adsorption efficiency increases at higher temperatures, and a maximum adsorption efficiency is observed at a pH of 11.4. The adsorption isotherms proposed by Freundlich and Langmuir are examined to confirm the adsorption mechanism, which entails the creation of a single layer of dye molecules on the adsorbent's surface. Analysis of kinetic parameters indicates that the reaction follows pseudo-second-order adsorption kinetics. The composite produced demonstrates effectiveness as an adsorbent for removing harmful organic pollutants from water sources.

Comparative Study on Structural, Dielectric Behavior and AC Conductivity of PPY-PVA Incorporated with TiO2 Fine and Nano Particles

Abstract An in-situ oxidative chemical polymerization technique to prepare thin films of PPY, PVA, and PPY-PVA blend doped with variable concentrations of TiO2 fine- and nano-particles was further investigated by X-ray diffractometer (XRD) and impedance spectrometer to study structural, dielectric, and AC conducting behavior. XRD spectra established that sharp and high intense peaks of PPY-PVA- fine TiO2 films indicated more crystallinity, which might be due to higher compactness and modification in interplanar spacing. Dielectric plots revealed that PPY-PVA-nano TiO2 films exhibited higher dielectric constants and lower dielectric loss compared to films of PPY-PVA- fine TiO2 in shorter frequency region, suggesting that these films are more suitable for charge storage devices. Conductivity plots revealed that AC conductivity of pure PPY was low (4.8 x10-3 S/cm at 313 0K) and was increased to 5.3 x10-3 S/cm by addition of PVA. AC conductivities of PPY-PVA-nano TiO2 thin films are relatively higher (7.43x10-3 S/cm to 1.14x10-2 S/cm) than PPY-PVA-fine TiO2 films (6.35x10-3 to 9.78x10-3 S/cm) with increasing frequency and temperature, which could be due to large surface area to volume ratio of nano-size dopant. This suggests that PPY-PVA-nano TiO2 thin films may be used for sensing various gasses.

Investigation of polypyrrole/TiO2 and poypyrrole/WO3 nanocomposites as anode modifier in salt bridge microbial fuel cell using municipal wastewater

Developing nanocomposite materials based on conducting polymers (CPs) and metal-oxide nanoparticles, which combine redox electrochemistry of CPs with intrinsic properties of nano-scale semiconducting materials, may offer improved microbial fuel cells (MFCs) performances. Polypyrrole (PPY) based nanocomposites were synthesized by chemical oxidative polymerization method and were further used as an anode modifier in salt bridge MFCs. The PPY-based nanocomposites were characterized by X-ray diffraction, Fourier-Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM). The maximum power density of 16.7 mW/m2, 20.1 mW/m2, and 22.5 mW/m2 were obtained for MFC2-PPY, MFC3-PPY/TiO2 and MFC4-PPY/WO3 respectively, suggesting that modification of the anode with PPY- based nanocomposites is beneficial in the electricity generation of the MFC, and have superior performance as compared to the controller MFC1-CC (11.6 mW/m2).

Acid content sensitive colorimetry of poly-N-phenyl-o-phenylenediamine for state of charge determination of lead-acid battery

The ex-situ colorimetric method of battery acid estimation was developed using poly-N-phenyl-o-phenylenediamine (PPOPD) to accurately determine the lead acid battery's state of charge (SoC). PPOPD was synthesized by the in-situ oxidative chemical polymerization of N-phenyl-o-phenylenediamine monomer (POPD) using ferric chloride as an oxidizing agent in ethanol solvent. The UV–visible absorption peak of PPOPD in acidic solutions at 518 nm showed a sharp positive linear slope with increased acid content. The charging or discharging mechanism of the battery produces changes in battery acid content. A fully charged lead-acid battery contains approximately 39.7 % sulphuric acid, whereas its acid content decreases by approximately 10 % on discharge. The PPOPD polymer showed a change in absorbance with a change in the lead-acid battery's acid percentage, which can be correlated with the state of charge. The absorbance of PPOPD solution was calibrated linearly with the sulphuric acid percentage (6–40 %), a similar acid range produced inside the battery during charging or discharging. The absorbance of PPOPD solution obtained in 10 % and 40 % sulphuric acid at 518 nm was set as the lower and upper limits (Amin and Amax) respectively for SoC determination. Therefore, the state of charge in any lead-acid battery under investigation can be determined by measuring the absorbance of the PPOPD solution. The state of charge obtained from the colorimetric method was compared with an open circuit voltage method using a 12 V lead-acid battery.

Tailoring polypyrrole film characteristics with multi-step oxygen plasma treatment for high-performance strain sensors: Impact on bonding, microstructure, and electrical responsivity

We investigate the impact of oxygen plasma treatment (O2 PT) on the performance of polypyrrole (PPy)/polydimethylsiloxane strain sensors. Utilizing a three-step chemical oxidative polymerization method for PPy growth, we explore various durations of O2 PT (0, 30, 60, and 90 s) during intermediate growth stages. Through analyses using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, we elucidate the relationship between O2 PT, structural changes, and strain sensor performance. Sensor devices plasma-treated for 30 s exhibit exceptional characteristics: a gauge factor of 432 at 50% strain and a response time of 50 ms under quasi-step function strain variation from 0% to 1% in 40 ms. These results underscore the pivotal role of O2 PT in enhancing the performance of PPy-based strain sensors, providing insights for advanced sensor design and fabrication techniques.

Positional Isomeric Effects on the Physicochemical Properties of Polymeric Matrix and Polymer@TiO2 Nanocomposites

This study investigates the influence of positional isomerism on the physicochemical characteristics of polymeric matrices by examining polyo-anisidine (POA) and polyp-anisidine (PPA) in conjunction with TiO2 nanoparticles. The synthesis of POA@TiO2 and PPA@TiO2 involved chemical oxidative polymerization. X-ray diffraction analysis revealed the anatase structure of TiO2 nanoparticles. Transmission electron microscopy confirmed the successful integration of TiO2 nanoparticles within the polymer matrix. Moreover, FTIR and UV–Vis spectroscopy confirmed the effective interaction between the nanoparticle and the polymer. TGA indicated that POA@TiO2 exhibited a lower weight loss than PPA@TiO2, suggesting an enhancement in thermal stability. Although the incorporation of TiO2 nanoparticles led to a reduction in the electrical conductivity of the pristine polymers (PPA and POA), the resultant nanocomposites retained high conductivities within the range of 0.08 to 0.34 S.cm−1. Furthermore, the POA-based polymer matrix displayed promising electrochemical properties. Significantly, the adherence of the POA layer to TiO2 nanoparticles suggests potential practical applications.

Multifunctional enhanced energy density of flexible wide-temperature supercapacitors based on MXene/PANI conductive hydrogel

Conducting polymer-based conductive hydrogels can offer adjustable electronic characteristics and superior mechanical performance, thus holding significant promise for flexible supercapacitors. However, some of such hydrogel electrodes still suffer from inferior stability, unsatisfactory energy density, and narrow temperature tolerance, which limit their widespread use in flexible supercapacitors. Herein, polyaniline was coated on the surface of Ti3C2Tx MXene flakes by in-situ chemical oxidative polymerization of aniline monomer pre-assembled on the MXene surface. The resulting MXene/PANI conductive nanofillers, Fe3+ ions, and phytic acid were introduced into the gelatin/polyacrylamide hydrogel scaffold to form highly stretchable MPGP-Fey hydrogel electrodes. Benefiting from the highly electrochemical activity of MXene/PANI conductive nanocomposite, efficient redox transition of Fe3+/Fe2+, and high open structure, the assembled all-gel symmetrical MPGP-Fey supercapacitors can achieve a maximum specific capacitance of 847 mF/cm2, an impressive energy density of 71.8 μWh/cm2, and an exceptional cyclic stability, retaining 95 % capacitance retention after 5000 cycles. The phytic acid is advantageous in lowering the freezing points of both the hydrogel electrode and electrolyte layer. The developed supercapacitors demonstrate promising temperature-adaptive properties over a wide range of −30 ∼ 90 °C. When operated at −30 °C, an impressive stable output with long-term stability of 93 % retention are achieved. With the merits of good processability, high flexibility and stretchability, the present device can serve as an optimal energy source for powering diverse electronic components in practical applications.

Development of surfactant integrated polyaniline based electrode material towards supercapacitor application

Tailoring electrode material is always important for fabricating high-performance energy storage devices. Polyaniline (PANI) is one of the most-explored electrode materials due to its electroactivity, redox property, easy and cost-effective synthesis and reasonable capacitance. Herein, PANI has been integrated with surfactants (cetyltrimethylammonium bromide, dioctyl sodium sulfosuccinate, sodium lauryl sulphate, Tween-80) via chemical oxidative polymerization pathway and utilized as the electrode material for supercapacitor. Chemical nature, crystallinity and morphology of surfactant integrated PANI samples were evaluated by FTIR, UV–Visible, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques while electrochemical properties were investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy studies. Among the different PANI samples, PANI integrated with cetyltrimethylammonium bromide (PMC) afforded 2.3 times higher capacitance (528 F/g) than PANI synthesized without surfactants (PM) (229 F/g). Due to the influence of CTAB, PMC displayed higher pore volume and lesser particle size as investigated by Brunauer-Emmett-Teller and dynamic light scattering analyses. Furthermore, PMC displayed two times higher electroactive surface area as compared to PM as investigated by cyclic voltammetry studies. It has been observed that the surfactant not only improved the processability of the polymer but also assisted in enhancing the capacitance of the electrode material significantly.

Development of PANI/FeS2/MnO2 Composite Electrode Materials for High‐Performance Supercapacitors

AbstractPolyaniline (PANI) has unique physical and chemical peculiarities, so it has been widely researched in the field of energy storage. However, its structure is easy to be damaged during charging and discharging, which seriously affects its application. PANI/FeS2/MnO2 composite materials were successfully prepared by an easy combination of chemical precipitation and chemical oxidative polymerization. The electrochemical test results manifested that the specific capacitance of PANI/FeS2/MnO2 4 : 1 : 3 was 580 F/g at 1 A/g, and had great cyclic stability (capacitance retention rate was 85.2 % after 10000 cycles at 5 A/g). It was because that reticular structure shortened the ion transport path. On the other hand, it was able to effectively mitigate the volume change during long‐term charging and discharging, thus improving the cycling stability. In addition, PANI/FeS2/MnO2 4 : 1 : 3 as the positive and activated carbon (AC) as the negative, an asymmetrical supercapacitor was assembled with a maximal energy density of 37.93 Wh/kg when its power density was 0.85 kW/kg. At the same time, the device possessed a long cycle life (the capacitance conservation rate was 82 % after 5000 cycles at 5 A/g). This excellent performance is due to the excellent synergy between the PANI, FeS2 and MnO2. This study opens a new way to investigate polyaniline‐based composite electrode materials.

Polyrhodanine-Functionalized Magnetic-Activated Carbon for Efficient Removal of Lead Ions and Malachite Green From Wastewater

The development of wastewater treatment agents with high treatment capacity and efficient separation is crucial for the remediation of heavy metal ions and organic dye wastewater. In this study, a polyrhodanine functional magnetic-activated carbon composite (PR-mAC) was synthesized via a one-step co-precipitation method combined with chemical oxidation polymerization. As an innovative water treatment agent, PR-mAC possesses not only environmentally friendly and easily obtainable raw materials but also magnetic properties that facilitate its reusability. Notably, PR-mAC exhibited remarkable removal efficiency towards lead ion (Pb(II)) and malachite green (MG). Experimental results demonstrated that the adsorption of Pb(II) and MG followed quasi-second-order kinetic model, while the Hill isothermal adsorption model and Redlich–Peterson isothermal adsorption model were suitable for Pb(II) and MG removal, respectively. All adsorption processes were spontaneous endothermic reactions. The maximum adsorption capacities reached 223.71 mg/g and 315.46mg/g, respectively. Even after undergoing 5 cycles, the material maintained satisfactory removal performance for Pb(II) and MG pollutants. Therefore, the prepared PR-mAC represents an optimal agent for wastewater treatment due to its effective capability in removing both metal ions and dyes.

Tailoring a Multifunctional PEDOT/Co3O4‐CeO2 Composite for Sustainable Energy Applications

AbstractEnergy sources play a crucial role in the development of the society. The gargantuan depletion of fossil fuels creates new glitches in the routine activities of human beings. Electrocatalysts can efficiently produce and store energy and, therefore, have the potential to alleviate this situation. A multifunctional electrocatalyst, Poly (3,4‐ethylenedioxythiophene)/cobalt oxide‐cerium oxide(PEDOT/Co3O4‐CeO2), is synthesized by incorporating mixed metal oxide to 3,4‐ethylenedioxythiophene (EDOT) using the in situ chemical oxidative polymerization method and is employed for both energy production and storage applications. The successful synthesis of the catalyst is confirmed through various characterization techniques. The composite shows a specific capacity of 617.8 C g−1 and a specific capacitance value of 1298.1 F g−1. The hydrogen evolution reaction (HER) analysis shows that the composite requires a low overpotential of 163.1 mV at a current density of 10 mA cm−2. Synthesized electrocatalysts can effectively handle the energy related issues prevailing in the society.

Conducting polymer hollow nanostructures by surfactant-free Ouzo emulsion for an exceptional EMI shielding performance

Hollow or partially collapsed bowls of conducting polymers, such as poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (Ppy), polyaniline (PANI), and polythiophene (PT), have successfully been synthesized by surfactant-free Ouzo emulsion. The stable Ouzo region has been identified based on three-component phase diagram of FeCl3·6H2O as an oxidant, acetone as solvent, and toluene as anti-solvent, respectively. The solvent/oxidant mixture forms emulsion droplets in anti-solvent medium spontaneously without any surfactant. It is the very first report on the generation of Ouzo state in the chemical oxidative polymerization systems of conducting polymers. Cast thin film of the synthesized conducting polymer hollow nanostructures was infiltrated with commercial PEDOT:PSS solution for the formation of composite structures, where the highly conductive networks of PEDOT:PSS ensures electrical conductivity. In the meanwhile, the embedded hollow nanostructures enable multiple scattering of incident electromagnetic wave. A thin (∼6 μm) composite film shows exceptional electromagnetic interference (EMI) shielding effectiveness of ∼75 dB in X-band (8–12 GHz). Furthermore, thanks to low density of hollow conducting polymer nanostructures, thickness-normalized specific shielding effectiveness (SSE/t) shows the highest value compared to other materials published in literature. The hollow nanostructures of conducting polymers, formed using surfactant-free Ouzo emulsion, may find broader applications thanks to its simple and contaminant-free nature.

Engineering 3D-interconnected graphene nanoplatelets and polyaniline nanocomposite for high energy density energy storage

A high-performance, seaweed-shaped 3D interconnected nanocomposite electrode comprising graphene nanoplatelets (GNP) and polyaniline (PANI) as an electrode material for supercapacitors is synthesized via conventional in-situ chemical oxidative polymerization. This research aims to enhance the electrochemical performance of the GNP/PANI nanocomposite electrode material by manipulating their shape and electroactive characteristics for greater optimization. While seaweed-shaped GNP/PANI nanocomposites have been reported previously, none have demonstrated high electrochemical performance with an optimized 40 wt% of GNP in GNP/PANI nanocomposite. This deficiency is attributed to the lack of 3D well-interconnected nanocomposite formation and the electroactivity of GNP/PANI when compared to individual PANI or GNP in H2SO4 electrolyte.The electrochemical study confirms an upward revision in specific capacitance, from 400 Fg−1 for GNP and 514 Fg−1 for PANI, to 1088 Fg−1 for the GNP/PANI electrode material in an aqueous 1 M H2SO4 electrolyte solution. It is envisioned that formation of such 3D interconnected GNP/PANI nanocomposite contributes in increasing the interplanar and interchain distances in the nanocomposite particularly in GNP layered structure. Additionally, it is observed that the electrochemical impedance parameters, such as charge transfer resistance Rct (0.12 Ω), high response frequency (1.367 Hz), and short relaxation time (τo ∼ 0.73 s) of the GNP/PANI nanocomposite electrode material, demonstrate excellent performance. The seaweed-shaped GNP/PANI nanocomposite exhibits promising potential as an electrode material for next-generation symmetric supercapacitors due to its high specific capacitance, low cost, and ease of fabrication.

Co-doped polyaniline composites for biological application: Morphological, functional, optical and antibacterial activities

In the present work, we have successfully synthesized co-doped polyaniline (PANI) composites with various organic acids DBSA, phthalic acid, oxalic acid and Calotropis proceralatex using a simple chemical oxidative polymerization method. The structural, optical, surface morphology and antibacterial analyses were carried out for the synthesized PANI (DBSA-Phthalic acid), PANI (DBSA-Oxalic acid) and PANI (DBSA-C.Procera latex) composites. The structural characterization using XRD and FT-IR measurements confirmed the formation of emeraldine salt form of PANI from the observed characteristic peaks of PANI in all the composites. The observed UV–visible absorption and PL emission peaks also assured the synthesis of PANI in emeraldine form. SEM micrographs of PANI (DBSA-phthalic acid) composites exhibited continuous rock-like agglomerated structure. The antibacterial activity tested against medically important bacteria Bacillus subtilisrevealed a maximum inhibition zone for the DBSA-phthalic acid doped PANI composites when compared with other composites. The average value of zone of inhibition for the PANI composites is found to be 21–24 nm. The minimum inhibitory concentration (MIC) is found to be 1 mg/L for all the PANI composites whereas the minimum bactericidal concentration (MBC) is found to be 60 mg/L for PANI (DBSA-Phthalic acid) and 80 mg/L for PANI (DBSA-Oxalic acid), PANI (DBSA-C.Procera latex) composites. A larger and clear zone of inhibition exhibited by the synthesized co-doped PANI composites confirms their potential as an effective antibacterial agent.

Investigating the chemical oxidative polymerization of 1,8 - dihydroxynaphthalene using a correlative in-situ approach

Investigating the chemical oxidative polymerization of 1,8 - dihydroxynaphthalene using a correlative in-situ approach

Fabrication of polypyrrole conductive matrix covered MnNi2O4 nanocomposite as a positive electrode material for asymmetric supercapacitor applications

In this study, we successfully prepared a polypyrrole conductive matrix (PPY) covered manganese nickel oxide (MnNi2O4) nanocomposite via co-precipitation and a chemical oxidative polymerization route.

An efficient hexavalent chromium scavenger: Polyaniline

Hexavalent chromium ions are a significant type of heavy metal pollutant in water, posing a severe threat to the environment and biological health. Various methods are employed for treating heavy metal wastewater, including traditional, biological, physical, and chemical adsorption, and membrane separation methods. This study focuses on utilizing chemical oxidation polymerization to synthesize polyaniline, followed by structural characterization and performance evaluation. The research shows the material’s exceptional adsorption capacity for Cr(VI) ions under different conditions. The experiments specifically demonstrate a direct relationship between the rate of removal and the proportion of adsorbent utilized in comparison to the Cr(VI) initial concentration. Furthermore, adjusting the pH level during testing shows an increase in the removal rate as the pH decreases, with a peak removal rate of 57.94% at pH 1.02. By aligning with a pseudo-second-order kinetic model, the material demonstrates its potential for efficient and effective removal of Cr(VI) contaminants.

Water pollution remediation: Synthesis and characterization of poly(o‐methylaniline)/ZnO/rGO composite for photocatalytic degradation of dyes

AbstractWater pollution is growing at an alarming rate, particularly due to the colored wastewater released by the various industries into aquifers and fresh water sources, and in some extreme cases, they have reached the water table. Faisalabad, a city in Pakistan where there is an industrial cluster of textiles dyeing and manufacturers, water table has become undrinkable. The presence of hazardous dyes and chemicals imposes serious health issues on humans, animals, and plants. The treatment of such toxic dye effluents is crucial and could be done by efficient degradation methods such as photocatalysis. The current study presents synthesis of poly(o‐methylaniline)/zinc oxide/reduced graphene oxide nanocomposite (POMA/ZnO/rGO NC) using a chemical oxidative polymerization process and explores its properties as a photocatalyst by demonstrating degradation of three dyes. The composite was characterized using X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), photoluminescence emission spectroscopy (PL), Brunauer Emmett–Teller analysis (BET), and UV–visible spectroscopy (UV–visible). Further, the photocatalytic activity of POMA/ZnO/rGO NC was evaluated and compared by degrading the direct yellow 12 (DY 12), congo red (CR), and malachite green (MG) dyes in aqueous media under UV irradiation. The results indicated that after 110 min, POMA/ZnO/rGO composite degraded the dyes by 92% (DY 12), 86.1% (CR), and 82.1% (MG), respectively. Moreover, kinetic studies of the photocatalyst were also performed along with reusability test, total organic carbon, chemical oxygen demand, and degradation mechanism.