Carbon Nitride Composites Research Articles

Photocatalytic degradation of organophosphorus pesticide (terbufos) in aqueous solutions using 3D-printed TaSe2/g-C3N4 nanocomposites

The combination of transition metal dichalcogenide of TaSe2 with a composite of graphitic carbon nitride (g-C3N4) and 3D printing technology enhanced the photocatalytic degradation of organophosphorus pesticide, terbufos from aqueous solutions using the 3D-printed TaSe2/g-C3N4 nanocomposites. The 3D-printed TaSe2/g-C3N4 composites efficiently degrade terbufos upon exposure to UV light, reaching more than 95% degradation of 10 ppm terbufos with a decomposition rate constant of 0.3305 min-1. This rate is 37% more enhanced than that of TaSe2/g-C3N4 (0.2409 min-1) and 57.98% more than that of g-C3N4 (0.2092 min-1). Under visible light, terbufos degradation was achieved in 90 min at a slower rate of 0.0492 min−1, and 6.72 times less efficient than under UV light, emphasizing the superior efficiency of UV light for this system. Additionally, the mechanism, degradation pathway, and reusability of the materials are explored, underscoring the potential of 3D-printed TaSe2/g-C3N4 as a potential nanocomposite for photocatalytic applications.

Hydrogen bond-induced supramolecular self-assembly strategy to fabricate ultra-dispersed Cu-loaded porous tubular graphitic carbon nitride with rich nitrogen vacancies and CuNx sites for efficient photo-Fenton catalysis

The low utilization of visible light and easy recombination of charge carriers of graphitic carbon nitride (CN) restrain its application as photo-electron donor and metal site support in photo-Fenton system. Herein, a hydrogen bond-induced supramolecular self-assembly strategy was created to fabricate an ultra-dispersed Cu-loaded porous tubular CN composite (CA-Cu/TCN) by the hydrothermal–pyrolysis method with citric acid (CA) as initiator and chelating agent. CA-Cu/TCN with rich nitrogen vacancies (NVs) and abundant ultra-dispersed CuNx sites exhibited narrow bandgap, favorable visible light absorption capability, and high separation and transfer efficiency of charge carriers. CA-Cu/TCN effectively catalyzed the activation of H2O2 for generating abundant reactive oxygen species under visible light irradiation, contributing to efficient degradation of ciprofloxacin (CIP) with removal rate of 95.9 % and kinetic rate constant of 0.0948 min−1. The superior catalytic activity of CA-Cu/TCN can be ascribed to the effective transport of photogenerated electrons, high specific surface area, atomically dispersed Cu species, and enriched surface NVs. The mechanism of photo-Fenton catalytic degradation of CIP and possible degradation pathways were proposed as the dominant role of 1O2. Toxicity evaluation of CIP and intermediates indicated that the degradation of CIP was a gradual detoxification process. This work offers a novel self-assembly strategy to design and synthesize highly active and sustainable visible light-driven photo-Fenton catalysts for effectively degrading organic pollutants.

Ultrathin Porous Carbon Nitride Anchored with Pt Nanoclusters for Synergistic Enhancement of Hydrogen Production in Alkaline Photocatalytic Polyester Reforming.

Photocatalytic reforming (PR) of polyester waste, fueled by renewable sources like solar energy, offers a sustainable method for producing clean H2 and valuable by-products under mild conditions. The design of high-performance photocatalyst plays a pivotal role in determining the efficacy of an alkaline polyester PR system, influencing H2 generation activity and selectivity. Here, ultrathin porous carbon nitride nanosheets (UP-CN) loaded with Pt nanoclusters (Pt NCs, average diameter of 1.7nm) with uniform Pt NCs distribution are introduced. The resulting Pt NCs/UP-CN catalyst can accelerate charge and mass transfer while providing additional active sites, achieving superior H2 generation rates of 11.69mmol gcat -1 h-1 and 2923mmol gPt -1 h-1 under AM 1.5 light, which nine times higher than that of Pt nanoparticles-bulk graphitic carbon nitride composite (1.29mmol gcat -1 h-1 and 258mmol gPt -1 h-1) as counterpart. This performance also surpasses that of previously reported carbon nitride-based and TiO2-based photocatalysts. Moreover, the density functional theory calculations reveal a significant reduction in the energy barrier for the water dissociation step (H2O + * → *H + OH) at the interface between UP-CN and anchored Pt NCs, showcasing the synergistic effect between Pt NCs and UP-CN. This catalytic system also exhibits universality across various polyester plastics.

Co-regulation of microstructure and intrinsic groups in carbon nitride to achieve high-efficient pollutant degradation under visible light: Roles of N species

Owing to the drawback of the lower separation and shorter lifetime of carriers in carbon nitride (CN), this study reported that the CN composites with different morphologies and the N species were successfully synthesized through the regulation of intrinsic functional groups. Results showed that the formed tubular structure in 1D CN nanotubes (1D CNNTs) could intensify the utilization of visible light (Vis) because of the multiple diffraction or scattering of light, bridge the mass transfer distance and provide more active sites. Meanwhile, 1D CNNTs showed excellent TC degradation rates (0.3777 min-1) under Vis, which were 13, 630 and 6-36 times higher than these of two-dimensional CN nanosheets, three-dimensional CN microspheres and reported CN based catalysts, respectively. The analysis of active species showed O2·- and h+ were the main active species for TC degradation. The degradation pathways and comprehensive toxicities of TC were also comprehensively analyzed. Theoretical calculation exhibited that the introduction of N vacancy and -NHx groups effectively accelerating separation of carriers, prolonging carrier lifetime and enhancing the adsorption ability and relative electron transfer of O2 to the production of O2·-. In addition, the prepared catalysts presented better stability and anti-interference ability. Therefore, this study would provide a new view for regulation of intrinsic functional groups in CN to achieve efficient pollutant degradation under Vis.

Ordered porous carbon nitride embedded with truncated carbon nanotubes for boosting photocatalytic degradation

Limited light absorption and low charge separation rates are the main obstacles for graphitic carbon nitride-based photocatalysts. In terms of these defects, an ordered-porous graphitic carbon nitride composites (PCN@CNT) modified with truncated carbon nanotubes (CNTs) were composited through hydrothermal-calcination method in this work. Due to their electron trapping ability, the CNTs can enhance visible light absorption, narrow the bandgap, and act as electron concentrators, achieving that spatial separation of photogenerated carriers can inhibit electron-hole pair recombination efficiently. In addition, a controllable ordered-porous structure was constructed to provide abundant active sites and mass transfer channels, shortening the carrier migration path. These two modifications acted synergistically to enhance the catalysts' performance. The top-performing sample in this work, PCN@CNT-1, showed significant improvement in photovoltaic performance and achieved a 97.7 % degradation of rhodamine B, with a photocatalytic degradation rate constant (k-value) more than three times that of PCN. This work demonstrates the potential for modification by coupling CNTs to design carbon-nitride-based photocatalysts with excellent catalytic performance, which can be used as catalysts for wastewater purification.

Metal-Free Carbon Co-Catalysts for Up-Conversion Photo-Induced Catalytic Cancer Therapy.

Near-infrared (NIR)-responsive metal-free carbon co-catalysts that convert glucose into H2O2 to generate reactive oxygen species (ROS) are developed from phosphorus-doped carbon nitride (P-C3N4) and graphene quantum dots (GQD) composites, for enhanced photocatalytic cancer therapy by light exposure in the targeted tumor microenvironment. Upon irradiation, the NIR light is converted by GQD with up-conversion function into visible light to excite P-C3N4 for photocatalytic conversion of glucose into H2O2, which subsequently decomposes into ROS. ROS thus generated exhibits an excellent anticancer efficacy for efficient cancer therapy with minimal side effects, as evidenced by both in vitro and in vivo studies. This study demonstrates, for the first time, a cancer therapeutic of GQD/P-C3N4 composite that utilizes a two-step cascade effect using initially NIR-triggered GQD nanoparticles to activate P-C3N4 to photocatalytically generate ROS for effective and targeted cancer therapy.

Activation of peroxymonosulfate under visible-light illumination for enhanced degradation of acetaminophen by self-assembly iron phosphorus/hexagonal tubular graphite carbon nitride

Improving the visible light response by sulfate-based advanced oxidation processes (S-AOPs) is a promising method for the efficient degradation of organic matter in water. Herein, we facilely fabricated the iron phosphorus/hexagonal tubular graphite carbon nitride (FeP/HTCN) composites via two-phase hydrothermal supramolecular self-assembly and thermal-condensation method. FeP/HTCN with the shape of hollow hexagonal tubular loaded iron phosphorus particles was first synthesized. The results suggested that the loading of iron phosphate greatly enhanced its ability to activate peroxymonosulfate (PMS) while also improving the photocatalytic ability of the catalyst due to its smaller bandgap. The combined effect of iron phosphate, HTCN, and visible light (wavelength ≥ 420 nm) assistance facilitated the enhancement of the reaction activity. Electron paramagnetic resonance techniques (EPR) and radial quenching experiments validated that singlet oxygen (1O2) derived from superoxide was the main active species. The degradation pathways of acetaminophen (APAP) were determined and the mechanism of mineralization and decomposition was demonstrated. This work provided a proposal for the application of iron salts represented by iron phosphate in S-AOPs.

Fabrication of graphitic carbon nitride and black phosphorene composite based electrochemical sensor and application for sensitive determination of quercetin

A novel electrochemical method for sensitive detection quercetin (QU) was constructed with graphitic carbon nitride (g-C3N4) and black phosphorene (BP) composite (g-C3N4@BP) modified carbon ionic liquid electrode (CILE) as signal amplified interface. g-C3N4@BP was synthesized by a hydrothermal method with the characteristics investigated by SEM, XPS, FT-IR, XRD and electrochemical methods. Electrochemical behaviors of QU on the modified electrode (g-C3N4@BP/CILE) was investigated with the electrochemical parameters calculated and the experimental conditions optimized. The excellent electroanalytical result of QU was realized with the linear concentration range from 5.0 nmol/L to 90.0 µmol/L and a lower detection limit of 1.7 nmol/L (3σ). It was proved that the composite exhibited the synergistic effect of BP and g-C3N4 with more active sites, porous structure, large specific surface area, good electrical conductivity and strong electrocatalytic activity. The g-C3N4@BP/CILE was successfully used to detect the practical drug and food samples with satisfactory recoveries.

Bilamellar 1T-MoS2/g-C3N4 Composites with Enhanced Tribological Performance as Additives in Poly-α-Olefin Greases

In our research described here gold-phase molybdenum disulfide (1T-MoS2)/graphite-phase carbon nitride (g-C3N4) composites were prepared by a simple solvent-thermal method to investigate their synergistic lubrication in poly-α-olefin lithium grease by the four-sphere mode. The growth of 1T-MoS2 on g-C3N4 nanosheets was demonstrated by scanning electron microscopy (SEM), X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy (FTIR). Tribological tests showed that the best tribological performance of the poly-α-olefin grease was achieved when the concentration of 1T-MoS2/g-C3N4 was 3 wt%; the coefficient of friction and the diameter of the abrasion marks were reduced by 37.7% and 51.2%, respectively, compared with the pure grease. Investigating the wear marks by field emission scanning electron microscopy (FE-SEM) and elemental mapping analysis, it was found that the coupling between the liquid lubrication film and the solid friction film and the synergistic effect between 1T-MoS2 and g-C3N4 were important factors to improve the tribological performance of the poly-α-olefin grease. We, therefore, note this study is expected to promote the development of new, high-performance greases.

Preparation of magnetic carbon nitride composite toward phosphopeptide enrichment

Protein phosphorylation plays an important role in cellular signaling and disease development. Advances in mass spectrometry-based proteomics have enabled qualitative and quantitative phosphorylation studies as well as in-depth biological explorations for biomarker discovery and signaling pathway analysis. However, the dynamic changes that occur during phosphorylation and the low abundance of target analytes render direct analysis difficult because mass spectral detection offers no selectivity, unlike immunoassays such as Western blot and enzyme-linked immunosorbent assay (ELISA). The present study aimed to solve one of the key problems in the specific and efficient isolation of phosphorylated peptides. A method based on a magnetic carbon nitride composite coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was developed for the enrichment and analysis of phosphopeptides with low abundance in complex samples. Magnetic carbon nitride composite was synthesized and characterized by electron microscopy, infrared spectroscopy, and X-ray diffractometry. The composite showed a well-distributed two-dimensional layered structure and functional groups with excellent paramagnetic performance. Two classical phosphoproteins, namely, α- and β-caseins, were selected as model phosphorylated samples to assess the performance of the proposed enrichment technique. The magnetic carbon nitride composite exhibited high selectivity and sensitivity for phosphopeptide enrichment. The limit of detection was determined by MALDI-TOF-MS analysis to be 0.1 fmol. The selectivity of the method was investigated using the digest mixtures of α-casein, β-casein, and bovine serum albumin (BSA) with different mass ratios (1∶1∶1000, 1∶1∶2000, and 1∶1∶5000). Direct analysis of the samples revealed the dominance of spectral signals from the abundant peptides in BSA. After enrichment with the magnetic carbon nitride composite, the high concentration of background proteins was washed away and only the signals of the phosphopeptides were captured. The signals from the casein proteins were clearly observed with little background noise, indicating the high selectivity of the composite material. The robustness of the method was tested by assessing the reusability of the same batch of magnetic carbon nitride materials over 20 cycles of enrichment. The composite showed nearly the same enrichment ability even after several cycles of reuse, demonstrating its potential applicability for a large number of clinical samples. Finally, the method was applied to the analysis of phosphopeptides from several commonly used phosphoprotein-containing samples, including skimmed milk digest, human serum, and human saliva; these samples are significant in the analysis of food quality, disease biomarkers, and liquid biopsies for cancer. Without enrichment, no phosphopeptide was detected because of the high abundance of nonphosphopeptide materials dominating the spectral signals obtained. After pretreatment with the developed magnetic carbon nitride composite, most of the phosphosites were identified with high selectivity and sensitivity via MALDI-TOF-MS. These results revealed the practicality of the developed approach for clinical applications. In addition, our method may potentially be employed for phosphoproteomics with real complex biological samples.

Coproduction of hydrogen peroxide and formic acid as potential hydrogen-carrier through photocatalytic reformation of sacrificial chemical

This study explores the challenges to photo-reforming sacrificial chemicals into beneficial by-products while improving photocatalytic activity in H2O2 production by addressing several issues. The resorcinol-formaldehyde/graphitic carbon nitride composite (RF0.2GCN) with nanosheet-like RF morphology achieved a higher degree of surface-to-surface contact through -C-NH-CH2- and -NH-CH-OH than the nanosphere (RF0.8GCN). The RF0.2GCN produced H2O2 at 325.2 µg g−1 s−1 in the presence of oxalic acid (OA) at pH 2.1 with apparent quantum yield (AQY) of 12.7 %. The conduction band position potential was +0.54 VNHE, which is thermodynamically unfavorable for H+/H2 (E°: 0.00 VNHE) and O2/·O2- (E°: −0.046 VNHE) reaction and also inhibits the decomposition of H2O2 (H2O2/·OH, E°: +0.39 VNHE). Furthermore, the decomposition of OA formed formic acid (FA) at 82 % selectivity and concurrent CO2·- formation could promote electron density in the conduction band via its electron-donating ability·H2O2 was purified by isolating FA using anion exchange resin, and FA was recovered by desorption from the resin using HCl (pH 3).

Fabrication of Z-scheme heterojunction of UCN/BWO for selective photocatalytic benzylamine oxidation

Nanosheet materials have larger specific surface area and more active sites than bulk materials. In this paper, ultrathin graphite carbon nitride (UCN) nanosheets were first prepared by a multi-step calcination method, and then Bi2WO6 nanoflowers were grown in-situ on the surface of UCN by a simple hydrothermal method to synthesize ultrathin graphite carbon nitride and bismuth tungstate composite (UCN/BWO). The synthesized catalyst was applied to the photocatalytic oxidative coupling of benzylamine (BA). After reacted 5 h under light in air atmosphere, BA was almost completely converted into N-benzylidenebenzylamine, which was 3.8 times higher than that of bulk graphite carbon nitride (BCN). The enhanced photocatalytic activity was not only attributed to the thin nanosheet structure of UCN which shortened the migration distance of photogenerated electrons, but also because the construction of Z-scheme heterojunction that inhibited the recombination of photogenerated carriers and improved the oxidation ability of the catalyst. Based on density functional theory (DFT) calculation and photoelectric performance test, the existence of Z-scheme heterojunction was proved. Combined with the active species capture experiments, the pathway of electron transfer in the reaction process and the possible reaction mechanism were proposed.

Solar-matched S-scheme ZnO/g-C3N4 for visible light-driven paracetamol degradation

In pursuit of an efficient visible light driven photocatalyst for paracetamol degradation in wastewater, we have fabricated the ZnO/g-C3N4 S-Scheme photocatalysts and explored the optimal percentage to form a composite of graphitic carbon nitride (g-C3N4) with zinc oxide (ZnO) for enhanced performance. Our study aimed to address the urgent need for a catalyst capable of environmentally friendly degradation of paracetamol, a common pharmaceutical pollutant, using visible light conditions. Here, we tailored the band gap of a photocatalyst to match solar radiation as a transformative advancement in environmental catalysis. Notably, the optimized composite, containing 10 wt.% g-C3N4 with ZnO, demonstrated outstanding paracetamol degradation efficiency of 95% within a mere 60-min exposure to visible light. This marked enhancement represented a 2.24-fold increase in the reaction rate compared to lower wt. percentage composites (3 wt.% g-C3N4) and pristine g-C3N4. The exceptional photocatalytic activity of the optimized composite can be attributed to the band gap narrowing that closely matched the maximum solar radiation spectrum. This, coupled with efficient charge transfer mechanisms through S-scheme heterojunction formation and an abundance of active sites due to increased surface area and reduced particle size, contributed to the remarkable performance. Trapping experiments identified hydroxyl radicals as the primary reactive species responsible for paracetamol photoreduction. Furthermore, the synthesized ZnO/g-C3N4 composite exhibited exceptional photostability and reusability, underscoring its practical applicability. Thus, this research marks a significant stride towards the development of an effective and sustainable visible light photocatalyst for the removal of pharmaceutical contaminants from aquatic environments.

Degradation of Methyl Red (MR) dye via fabricated Y2O3–MgO/g-C3N4 nanostructures: Modification of band gap and photocatalysis under visible light

In this study, graphitic carbon nitride (g-C3N4) composites with metal oxide nanoparticles (Y2O3, MgO) and their combination (CN, YCN, MCN and YMCN) were synthesized by an ultrasonic technique and were then characterized by different tools such as UV–Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis and X-ray photoelectron spectroscopy (XPS). From the XRD diffractograms of the YMCN ternary composite, the g-C3N4, cubic MgO and Y2O3 structural phases were identified. The morphology of the as prepared nanostructure from the SEM analysis revealed the dispersion of the metal oxides nanoparticles with the graphitic sheets and the presence of the corresponding elements were confirmed by the EDX and XPS data. The FT–IR bands confirmed the bonding of the metal oxides to the nitride host as indicated by the characteristic modes. A reduction of the band gap energies was confirmed by the UV–Vis to indicate its visible light possible photoactivity. Accordingly, its visible light driven photocatalytic performance was assessed for methyl red degradation. The degradation competence was highest for the ternary composite YMCN due to the coupling of the semiconductors which increases the absorption and the charge carriers’ separation as well. The kinetics of degradation was best described by pseudo-first-order, and the most active species were the holes and the hydroxyl radicals. Thus, the YMCN nanocomposite is a visible light-active photocatalyst which can be engaged in the degradation of organic pollutants.

One pot synthesis of multi-functional B doped g-C3N4-praseodymium oxide nanocomposites for colorimetric detection of Hg2+ ion and solar photocatalytic removal of toxic water pollutants

A novel praseodymium oxide-boron co-doped graphitic carbon nitride composite was synthesized via one-step solid-state thermal condensation of urea, orthoboric acid and praseodymium nitrate precursors. The prepared composites were characterized by various methods. All the prepared composites demonstrated multi-functional activities towards peroxidase-mimetic based colorimetric detection of Hg2+ ions and superior photocatalytic efficiency towards photodegradation of textile colorants, photoreduction of hexavalent chromium and nitro aromatics like para-nitro phenol (PNP) and para-nitro aniline (PNA). The superior photocatalytic activity can be attributed to the formation of type II heterojunction which facilitates charge separation and increases the lifetime of photogenerated charge pairs. As evident from the scavenger studies, these charge pairs are involved in the formation of superoxide and hydroxyl radicals. The superior activity of the optimum composite can be attributed to the porous flaky morphology, decreased optical band gap, heterojunction mediated charge separation, and praseodymium oxide's conductive nature. A linear range of about 0.25–800 nM of Hg2+ ions can be detected with a limit of detection (LOD) of 42.4 nM using the colorimetric strategy. The as-synthesized composite is thus a unique, efficient, economically viable, and excellent candidate for detecting and degrading various hazardous water pollutants.

Photo-induced CO2 cycloaddition and tetracycline degradation over novel FeOx modified defective graphitic carbon nitride composite

Utilizing sunlight to achieve CO2 conversion and environmental remediation has been a key focus. Herein, “all-in-one” graphitic carbon nitride (g-C3N4) composite-based photocatalysts were synthesized by a simple one-step low-temperature calcination. Lower calcination temperature resulted in defective g-C3N4 enriched in cyano and hydroxyl groups. It was found that by incorporating amorphous FeOX, the resulted FeOX/O-g-C3N4 photocatalyst shows very good performance towards both CO2 cycloaddition reaction and photo-Fenton degradation of tetracycline (TC). It was also found that the photocatalyst shows the highest styrene carbonate yield of 83% (23 mmol g−1 h−1) under ambient conditions, which is 13.8 times higher than that obtained over pure g-C3N4. The photocatalyst also exhibits a 4.7 times faster TC removal rate than that of pure g-C3N4. Systematic characterization and mechanism study demonstrate the role of defects and photo-induced charge carriers.

Adsorption and Photocatalytic Properties of Tris(4-aminophenyl)amine-based Polyimide/Graphitic Carbon Nitride Composites for Organic Dye Removal

Adsorption and Photocatalytic Properties of Tris(4-aminophenyl)amine-based Polyimide/Graphitic Carbon Nitride Composites for Organic Dye Removal

Synthesis and Characterization of Silver Vanadate and Graphitic Carbon Nitride Composites

Various silver vanadate and graphitic carbon nitride (AgVA/g-C3N4) composites with different weightage of 10 wt%, 30 wt% and 50 wt% of AgVA were synthesized using wet chemical method and the prepared samples were named as A10, A30 and A50. Based on SEM analysis, the synthesized pure g-C3N4 exhibited a two-dimensional structure with typical irregular porosity whereas pure AgVA had a rod-like shape. The diffraction peaks of both g-C3N4 and AgVA could be observed in the composites, indicating that AgVA had been successfully coupled with g-C3N4. The stretching vibration of V-O was found in in pure AgVA and all composites. EDX analysis confirmed the presence of C, N, Ag, V and O element in the prepared composites. A10 was found to possess a larger BET specific surface area, smaller particle size and larger pore volume compared to that of pure g-C3N4.

The visible light photocatalytic performance of g-C3N4 is regulated by the Brønsted acid site on the mullite surface

Clay minerals are considered promising semiconductor carrier materials due to their unique physical and chemical properties. However, the exact mechanism by which clay minerals interact with semiconductor materials remains unknown. To this end, the present study was conducted to explore the formation of Brønsted acidic sites on the surface of mullite by modulating the cation types in mullite. It was hereby demonstrated for the first time that the presence of Brønsted acidic sites on the surface of clay minerals is conducive to the formation of N vacancies and dopant O in carbon nitride composites (CNM-30). The synergistic effect of N vacancy and doped O increases the specific surface area of CNM-30, enhances the electron-hole separation and transport efficiency, and ultimately makes CNM-30 produce more reactive oxygen species. CNM-30 possesses excellent degradation ability for gaseous phase pollutants (such as NO) and high concentration liquid phase pollutants (such as RhB and TC). Overall, this paper presents a new perspective on the design and development of semiconductor materials based on clay minerals.

Green ternary composite of graphitic carbon nitride/TiO2/ polyorthoanisidine for the enhanced photocatalytic treatment of Direct Red 28 for industrial water treatment solutions.

Industrial dye effluent causes significant risks to the environment. The present study was focused on photocatalytic degradation of the dye Direct Red 28 using a ternary composite of graphitic carbon nitride, TiO2, and polyorthoanisidine (g-C3N4/TiO2/POA), prepared by in-situ oxidative polymerization o-anisidine. The synthesized composite g-C3N4/TiO2/POA properties were characterized using different analytical techniques. X-ray diffraction (XRD) results revealed the prominent pattern of TiO2 and g-C3N4 in the composite peak at 2θ° while Fourier transform infrared (FTIR) results provided the confirmation peaks for g-C3N4/TiO2/POA and POA at 1,110cm-1 and 1,084cm-1 for C-O-C ether. Scanning electron microscopy (SEM) demonstrated an increase in the average size of the composite up to 428nm. The energy-dispersive X-ray spectroscopy (EDX) spectrum provided the weight percentages of the C, O, and Ti in the composite were 8.5%, 45.69%, and 45.81%, respectively. The photocatalytic degradation of Direct Red 28 dye under UV irradiation using a composite showed that 86% Direct Red 28 dye was degraded by a 30mg/L dose of g-C3N4/TiO2/POA in 240min at pH 2. After four consecutive cycles, the utilized composite showed 79% degradation of Direct Red 28, demonstrating the stability and effectiveness of the g-C3N4/TiO2/POA photocatalyst. The high reusability and efficiency of the g-C3N4/TiO2/POA composite are due to increased light absorption range and reduced e-/h+ recombination rate in the presence of g-C3N4 and POA.