g-C3N4 Nanoparticles Research Articles

Enhanced PMMA Denture Bases Using Functionalized MWCNT Fused g-C3N4 Nanocomposites

This study presents the development and analysis of a new metal-free nanocomposite that incorporates functionalized multi-walled carbon nanotubes (f-MWCNTs) with graphitic carbon nitride (g-C3N4) for reinforcing polymethyl methacrylate (PMMA) denture bases. The f-MWCNTs were integrated with g-C3N4 nanoparticles, and their structural and morphological features were examined using various techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared spectroscopy (FT-IR), and Raman spectroscopy. A mechanical blending process was employed to synthesize the nanocomposite by mixing 2 wt% of the f-MWCNT/g-C3N4 with PMMA polymer powder, followed by heat curing to form the composite material. Specimens for mechanical testing were crafted to measure flexural strength, impact resistance, compressive performance, and hardness. The findings revealed that the f-MWCNT/g-C3N4-reinforced PMMA composites outperformed standard PMMA in mechanical robustness. Surface examination of the tested samples through SEM showed distinctive dimpling and roughness, indicating a toughened fracture surface in comparison to pure PMMA and g-C3N4 samples. The study concludes that this innovative f-MWCNT/g-C3N4 composite is a promising reinforcement for PMMA denture bases, enhancing both their mechanical and physical attributes.Keywords: PMMA, functionalization, MWCNTs, Graphitic Carbide Nitride, Mechanical Properties and Denture Base

Glassy carbon electrodes modified with graphitic carbon nitride nanosheets and CoNiO2 bimetallic oxide nanoparticles as electrochemical sensor for Sunitinib detection in human fluid matrices and pharmaceutical samples.

Asophisticated electrochemical sensoris presented employing a glassy carbon electrode (GCE) modified with a novel composite of synthesized graphitic carbon nitride (g-C3N4) and CoNiO2 bimetallic oxide nanoparticles (g-C3N4/CoNiO2). The sensor's electrocatalytic capabilities for Sunitinib (SUNI) oxidation were demonstratedexceptional performance with a calculated detection limit (LOD) of 52.0nM. The successful synthesis and integrity of the composite were confirmed through meticulous characterization using various techniques. FT-IR analysis affirmed the successful synthesis of g-C3N4/CoNiO2 by providing insights into its molecular structure. XRD, FE-SEM, SEM-EDX, and BET analyses collectively validated the material's structural integrity, surface morphology, and electrocatalytic performance. Optimization of key analytical parameters, such as loading volume, concentration, electrolyte solution type, and pH, enhanced the electrocatalytic sensing capabilities of g-C3N4/CoNiO2. The synergistic interaction between g-C3N4 and CoNiO2 bimetallic oxide nanoparticles executed the sensor highly effective in the electrical oxidation of SUNI. Across a concentration range of 0.1-83.8µMSUNI, the anodic peak current exhibited a linear increasewith good precision. Application of the newly developed g-C3N4/CoNiO2 system to detect SUNI in a variety of samples, including urine, human serum, and capsule dosage forms, obtained satisfactory recoveries ranging from 97.1 to 103.0%. This methodology offers a novel approach to underscore the potential of the developed sensor for applications in biological and pharmaceutical monitoring.

Eco-Friendly g-C3N4/Carboxymethyl Cellulose/Alginate Composite Hydrogels for Simultaneous Photocatalytic Degradation of Organic Dye Pollutants.

The presented study was focused on the simple, eco-friendly synthesis of composite hydrogels of crosslinked carboxymethyl cellulose (CMC)/alginate (SA) with encapsulated g-C3N4 nanoparticles. The structural, textural, morphological, optical, and mechanical properties were determined using different methods. The encapsulation of g-C3N4 into CMC/SA copolymer resulted in the formation of composite hydrogels with a coherent structure, enhanced porosity, excellent photostability, and good adhesion. The ability of composite hydrogels to eliminate structurally different dyes with the same or opposite charge properties (cationic Methylene Blue and anionic Orange G and Remazol Brilliant Blue R) in both single- and binary-dye systems was examined through adsorption and photocatalytic reactions. The interactions between the dyes and g-C3N4 and the negatively charged CMC/SA copolymers had a notable influence on both the adsorption capacity and photodegradation efficiency of the prepared composites. Scavenger studies and leaching tests were conducted to gain insights into the primary reactive species and to assess the stability and long-term performance of the g-C3N4/CMC/SA beads. The commendable photocatalytic activity and excellent recyclability, coupled with the elimination of costly catalyst separation requirements, render the g-C3N4/CMC/SA composite hydrogels cost-effective and environmentally friendly materials, and strongly support their selection for tackling environmental pollution issues.

One pot synthesis of novel C3N4/C nanosheet composites under environmental benign molten salts for peroxymonosulfate activation with enhanced efficiency and reusability

The application of g-C3N4 based carbon materials in peroxymonosulfate (PMS) activation has faced challenges due to the electrochemically inert nature of nitrogen without light irradiation. In this study, two types of crystalline C3N4/C nanosheet composite catalysts were synthesized from glucose and dicyandiamide (DCD) via molten salt-assisted pyrolysis, denoted as M-GD and M-GD2. Both the composite catalysts showed significant improvement in the degradation of acid orange 7 amid PMS activation, taking the advantages of high graphitic N content and defect degree. Specifically, M-GD2 with excessive dosage of DCD exhibited a record catalyst specific activity value (0.0925 L min−1 m−2) in comparison with conventional C3N4 based carbon catalysts. The study also examined the effects of catalyst and PMS concentrations, temperatures, initial pH, and impurity ions on catalytic activity, as well as the catalytic performance in actual sludge wastewater cases. Notably, the M-GD2 catalyst exhibited exceptional regeneration capacity after four consecutive tests, attributed to its unique 3D structure comprising g-C3N4 nanoparticles loaded on crystalline C3N4/C nanosheets. Mechanism analysis revealed that a non-radical mechanism predominantly drove the PMS activation reaction, primarily involving catalyst-mediated electron transfer and surface-bound radicals due to the formation of catalyst-PMS* complexes. This work presents a facile and economical method for preparing defect-rich crystalline C3N4/C nanosheet composite with high graphitic N content, highlighting its catalytic activity, reusability, and regeneration performance synchronously. These findings contribute to advancing the field of PMS activation and offer promising applications in water environment remediation.

Ultrasensitive detection of Ag+ and Ce3+ ions using highly fluorescent carboxyl-functionalized carbon nitride nanoparticles

The fluorescence quenching of carboxyl-rich g-C3N4 nanoparticles was found to be selective to Ag+ and Ce3+ with a limit of detection as low as 30 pM for Ag+ ions. A solid-state thermal polycondensation reaction was used to produce g-C3N4 nanoparticles with distinct green fluorescence and high water solubility. Dynamic light scattering indicated an average nanoparticle size of 95 nm. The photoluminescence absorption and emission maxima were centered at 405 nm and 540 nm respectively which resulted in a large Stokes shift. Among different metal ion species, the carboxyl-rich g-C3N4 nanoparticles were selective to Ag+ and Ce3+ ions, as indicated by strong fluorescence quenching and a change in the fluorescence lifetime. The PL sensing of heavy metal ions followed modified Stern–Volmer kinetics, and CNNPs in the presence of Ag+/Ce3+ resulted in a higher value of K app (8.9 × 104 M−1) indicating a more efficient quenching process and stronger interaction between CNNP and mixed ions. Sensing was also demonstrated using commercial filter paper functionalized with g-C3N4 nanoparticles, enabling practical on-site applications.

Synergistic adsorption and photocatalytic degradation of tetracycline using a Z-scheme kaolin/g-C3N4/MoO3 nanocomposite: A sustainable approach for water treatment

This research focuses on the synthesis and application of a novel kaolin-supported g-C3N4/MoO3 nanocomposite for the degradation of tetracycline, an important antibiotic contaminant in water systems. The nanocomposite was prepared through a facile and environmentally friendly approach, leveraging the adsorption and photocatalytic properties of kaolin, g-C3N4 and MoO3 nanoparticles, respectively. Comprehensive characterization of the nanocomposite was conducted using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and optical spectra. The surface parameters were studied using N2 adsorption-desorption isotherm. The elemental composition was studied using X-ray photoelectron spectroscopy. The efficiency of the developed nanocomposite in tetracycline degradation was evaluated and the results revealed an efficient tetracycline degradation exhibiting the synergistic effects of adsorption and photocatalytic degradation in the removal process. The tetracycline degradation was achieved in 60 min. Kinetic studies and thermodynamic analyses provided insights into the degradation mechanism, suggesting potential applications for the nanocomposite in wastewater treatment. Additionally, the recyclability and stability of the nanocomposite were investigated, demonstrating its potential for sustainable and long-term application in water treatment.

Heterostructured S-TiO2/g-C3N4 Photocatalysts with High Visible Light Photocatalytic Activity

Novel heterojunctions associating graphitic carbon nitride g-C3N4 and S-doped TiO2 nanoparticles were successfully designed and prepared via a hydrothermal method and used for photocatalytic degradations. The loading in S-TiO2 nanoparticles on g-C3N4 was varied (5, 10 and 20 wt%), and the photocatalysts were characterized by XRD, FT-IR, solid-state UV-visible diffuse reflectance, photoluminescence, XPS, TEM and SEM. The S-TiO2 (5%)/g-C3N4 catalyst exhibits the highest activity for the photocatalytic degradation of the methylene blue (MB) dye under visible light irradiation. The high photocatalytic performance originates from the enhanced separation and transfer of photogenerated charge carriers. The S-TiO2 (5%)/g-C3N4 photocatalyst is stable and can be reused five times without a sharp drop in activity, indicating its high potential for wastewater remediation.

A visible-light-driven dual Z-scheme CeVO4/g-C3N4/LaNiO3 hierarchical nanostructure photocatalyst for effective removal of organic pollutants

The major obstacle to restrict the practical application of photocatalysts is the low separation efficiency of photo-induced charge carriers. To overcome the above problem, a novel ternary CeVO4/g-C3N4/LaNiO3 hierarchical nanostructure photocatalyst with dual Z-scheme heterojunction is designed and fabricated by feat of semiconductor energy levels matching engineering. First, one-dimensional (1D) LaNiO3 nanobelts are fabricated by an electrospinning technique. Second, zero-dimensional (0D) g-C3N4 nanoparticles are fixed on 1D LaNiO3 nanobelts through a direct gas-solid reaction. Finally, 1D CeVO4 needle-like nanorods are fixed on g-C3N4/LaNiO3 hierarchical nanostructures through a hydrothermal method. Following exposure to visible-light irradiation for 180 min, the optimized CeVO4/g-C3N4/LaNiO3 hierarchical nanostructure photocatalyst exhibits the highest photocatalytic degradation rate (87.57%) for tetracycline hydrochloride (TCH). Additionally, under the same conditions, the photocatalyst demonstrates its broad applicability by effectively degrading various organic pollutants, including methylene blue (MB) (60.56%), bisphenol A (BPA) (68.00%), ibuprofen (IBU) (57.56%), cefuroxime sodium (CRO) (77.34%), carbamazepine (CBZ) (59.65%) and ciprofloxacin (CIP) (75.16%). The exceptional photocatalytic performance of the CeVO4/g-C3N4/LaNiO3 hierarchical nanostructure photocatalyst can be attributed to the formation of a dual Z-scheme heterojunction among the 1D CeVO4 needle-like nanorods, 0D g-C3N4 nanoparticles, and 1D LaNiO3 nanobelts. The photocatalyst has a large specific surface area and suitable semiconductor energy band positions, providing the hierarchical nanostructures with numerous surface-active sites, rapid charge transfer ability and small charge recombination rate. The design ideas and preparation method proposed in this work have guiding significance for developing other dual Z-scheme heterojunction photocatalysts.

Elevating Supercapacitor Performance of Co3O4-g-C3N4 Nanocomposites Fabricated via the Hydrothermal Method.

The hydrothermal method has been utilized to synthesize graphitic carbon nitride (g-C3N4) polymers and cobalt oxide composites effectively. The weight percentage of g-C3N4 nanoparticles influenced the electrochemical performance of the Co3O4-g-C3N4 composite. In an aqueous electrolyte, the Co3O4-g-C3N4 composite electrode, produced with 150 mg of g-C3N4 nanoparticles, revealed remarkable electrochemical performance. With an increase in the weight percentage of g-C3N4 nanoparticles, the capacitive contribution of the Co3O4-g-C3N4 composite electrode increased. The Co3O4-g-C3N4-150 mg composite electrode shows a specific capacitance of 198 F/g. The optimized electrode, activated carbon, and polyvinyl alcohol gel with potassium hydroxide were used to develop an asymmetric supercapacitor. At a current density of 5 mA/cm2, the asymmetric supercapacitor demonstrated exceptional energy storage capacity with remarkable energy density and power density. The device retained great capacity over 6k galvanostatic charge-discharge (GCD) cycles, with no rise in series resistance following cyclic stability. The columbic efficiency of the asymmetric supercapacitor was likewise high.

Rational engineering of S-scheme CeO2/g-C3N4 heterojunctions for effective photocatalytic destruction of rhodamine B dye under natural solar radiations

Constructing heterojunction to achieve efficient charge separation and transportation is a significant way to enhance the photocatalytic activity to solve many water crisis. In this novel research, rational sonochemical engineering of S-scheme CeO2/g-C3N4 heterojunctions was carried out by hybridizing CeO2 as oxidative photocatalyst (EVB = +2.37 eV) with g-C3N4 nanosheets as reductive photocatalyst (ECB= −1.2 eV) for removal of rhodamine B dye under natural solar radiations. The morphology, nanostructure, textural properties and optical characteristics of the solid samples were investigated using X-ray diffraction [XRD], N2-adsorption isotherms, diffuse reflectance spectrum [DRS], X-ray photoelectron spectroscopy [XPS], photoluminescence [PL], scanning electron microscope [SEM], mapping, selected area electron diffraction [SAED] and high resolution transmission electron microscope [HRTEM] analysis. The co-existence of CeO2 and g-C3N4 diffraction peaks and the depression in the surface area to half its value implied the strong interfacial interaction between the two semiconductors due to the remarkable difference in the point of zero charge of both semiconductors. CeO2 nanoparticles transported the heterojunction absorbability to deep visible region compared with pristine g-C3N4. With sonochemical incorporation of various proportions of CeO2 on g-C3N4 sheets, the photocatalytic performance was enhanced and optimized for the heterojunction containing 15 wt% CeO2 that mitigated 98.9% of RhB dye during three hours under natural solar radiations. RhB dye decomposed over heterojunction surface containing 15 wt% CeO2 with pseudo-first-order rate of 0.0312 min−1 which is 16.4 and 34.7 times higher than that of g-C3N4 and CeO2 nanoparticles, respectively. The exceptional enhancement of the photocatalytic performance of CeO2/g-C3N4 heterojunctions was ascribed to the strong absorbability of natural solar radiations, limiting the electron-hole recombination rate and production of S-scheme heterojunction with auspicious redox power. Scavenger experimental results and PL analysis of terephthalic acid directed the mechanism of the photocatalytic charge transportation to S-scheme route. The results emerged from this research work revealed that novel S-scheme CeO2/g-C3N4 heterojunctions with robust oxidative-reductive efficiency are capable for destructing various organic pollutants exist in wastewater.

Kaolin supported synergistic effects in g-C3N4/V2O5 nanocomposite systems for advanced energy storage applications

In order to investigate the synergistic potential of a new nanocomposite for improved energy storage applications, this work combines graphitic carbon nitride (g-C3N4), vanadium pentoxide (V2O5) and kaolin. Kaolin functions as a structural matrix, offering stability and support for the integration of g-C3N4 and V2O5 nanoparticles. It is well-known for its wide availability and thermal characteristics. A variety of analytical methods, such as electrochemical analysis, scanning electron microscopy and X-ray diffraction, are used to characterise the synthesised nanocomposite. The specific capacitance and cycling stability of the nanocomposite's electrochemical performance are rigorously assessed. Key issues in efficiency, stability and cost-effectiveness are addressed by an optimised material for advanced energy storage systems, which is the result of the synergistic effects coming from the unique features of each component. With a superior cyclic stability and capacitance retention of 77.7 % even after 2000 cycles, the composite material exhibits a higher specific capacitance value of 415 Fg−1 at 5 mVs−1. This work is a major step towards the creation of novel nanocomposites for high-performing, environmentally friendly energy storage systems.

Direct Z-scheme photocatalytic removal of ammonia via the narrow band gap BiOCl/g-C3N4 hybrid catalyst upon visible light irradiation

In this study, a novel BiOCl/g-C3N4 heterojunction photocatalyst was successfully prepared. The resulting BiOCl/g-C3N4 catalyst can degrade NH3 effectively to N2 under visible-light irradiation. We used BiOCl-modified g-C3N4 nanoparticles to improve the activity of photochemically produced oxygen species. Photocurrent showed excellent photocatalysis performance of BiOCl/g-C3N4. The deposition of BiOCl resulted in a fatal decrease in the surface part and pore volume of the BiOCl/g-C3N4 samples. It was found that the photocurrent density increased with g-C3N4. Experimental results indicate that heterogeneous catalysts achieved 89.7 % degradation under visible light irradiation. The NH3 degradation product was N2 and neither NO2− nor NO3− were detected.

Organic pollutant degradation for micro-molecule product emission over SiO2 layers-coated g-C3N4 photocatalysts.

In this study, a SiO2 layer-coated g-C3N4 catalyst was prepared by a sol-gel method to overcome the poor adsorption ability and high recombination rate of charge carriers of pristine g-C3N4. SEM and TEM images indicated that SiO2 nanoparticles were coated on the surface of g-C3N4 nanoparticles with a layered structure and the layers were tightly contacted with g-C3N4. XRD patterns, FTIR spectra, UV-vis spectra and XPS spectra revealed that the structure of g-C3N4 was not destroyed and its photoelectric catalytic properties were not suppressed by the coating of SiO2 layers. Adsorption experiments revealed that the SiO2 layers improved the adsorption performance of g-C3N4 and their ratios were adjusted. The molecular weights of the final products of the degradation of RhB and antibiotics were at the micro-molecule level while the amount of g-C3N4 reached 1.2% of the mass fraction, which were more suitable for pollutant degradation compared with those of g-C3N4 due to its poor adsorption ability. The reason for this was likely that the SiO2 layers were not only beneficial for the adsorption of pollutants and intermediate products but also for prolonging the life time of the separated electrons and holes. Finally, active trapping experiments confirmed that both the holes and superoxide radicals were the main factors in the degradation of RhB and antibiotics, with the superoxides being the most active species.

Preparation and characterization of sulphur and zinc oxide Co-doped graphitic carbon nitride for photo-assisted removal of Safranin-O dye.

Recently, there has been significant interest in photocatalytic reactions involving graphitic carbon nitride (g-C3N4) due to its sp2-hybridized carbon and nitrogen content and it is an ideal candidate for blending with other materials to enhance performance. Here, we have synthesized and analyzed both doped and undoped g-C3N4 nanoparticles. Specifically, we co-doped sulfur (S) into g-C3N4, integrated it with ZnO particles, and investigated the photocatalytic potential of these nanocomposites to remove Safranin-O dye. The initial step involved the preparation of pure g-C3N4 through calcination of urea. Subsequently, S-g-C3N4 was synthesized by calcining a mixture of urea and thiourea with a 3 : 1 ratio. Finally, the ZnO-S-g-C3N4 composite was synthesized using the liquid exfoliation technique, with distilled water serving as the exfoliating solvent. These samples were characterized by advanced techniques, including UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), energy dispersive X-ray (EDX) and scanning electron microscopy (SEM), to assess their crystallinity, morphology, optical properties, and phase purity. Subsequently, these nanocomposites were employed in catalytic and photocatalytic processes to remove the Safranin-O dye (SO). The results highlighted the formation of Z-scheme junction responsible for ZnO-S-g-C3N4's significant performance improvement. The comparison of results demonstrated that S-g-C3N4 and ZnO-S-g-C3N4 composites revealed an effective removal of Safranin-O dye in the presence of UV-light as compared to pure g-C3N4, as it was attributed to the phenomenon of improved separation of photogenerated charge carriers as a result of heterojunction formation between S-g-C3N4 and ZnO interfaces. In addition to improving photocatalytic performance, this study presents a facile route for producing ZnO-S-g-C3N4 composite with superior adsorption capabilities and selectivity.

Trace carbon nitride-decorated SnO2 lamella boosting ultra-high response and fast recovery of NO2 gas at low temperature

The low-temperature NO2 gas sensors with ultra-high response are more helpful for their real-time and accurate monitoring in complex environment, however, the relevant reports are very less. Herein, we firstly prepared graphitic carbon nitride (g-C3N4) by pyrolysis of inexpensive melamine, which was used as template and directly soaked into SnCl4 ethanol/water solution. Afterwards, the immersed precursors were calcined to generate different SnO2-based materials. Among, the morphology of g-C3N4/SnO2-5 calcined at 500 °C is lamella structure composed of trace g-C3N4 and small-size SnO2 nanoparticles, which possesses narrow mesopores, large specific surface area, rich oxygen vacancy defects, as well as high concentration of surface O2-(ad) species. Under the synergy of multiple favorable factors, g-C3N4/SnO2-5 sensor exhibits ultra-high response (S = 12171) for 10 ppm NO2 gas at 92 °C, which is 1.93 times than that of SnO2-6 sensor. It is also the highest response value among reported g-C3N4/metal oxide composites. In addition, this sensor has fast recovery time (5 s), low detection limit, good moisture resistance and stability. Thus, the simple g-C3N4 template method provides a new strategy for the fabrication of gas sensors with highly efficient sensing ability.

Novel carboxymethyl cellulose/polyvinyl pyrrolidone hydrogel incorporating graphitic carbon nitride for quercetin delivery

Herein, quercetin (QC) as a model anticancer drug was encapsulated in a carboxymethyl cellulose/polyvinyl pyrrolidone/graphitic carbon nitride (g-C3N4) nanocomposite synthesized via dual oil-in-water emulsification method. The nanocomposite hydrogel showed a high surface area, nano-porous structure and a hydroxylated surface. g-C3N4 enhanced the drug loading efficiency up to 95 %. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) analyses provided information about the crystalline structure of the nanocarrier and the interactions between its components, respectively. Field-emission scanning electron microscopy (FESEM) showed its spherical shape, with a mean particle size of 160 nm. Dynamic light scattering (DLS) revealed a monomodal and narrow particle distribution, with a PDI value of 0.12. Further, the average zeta potential was −38.7 mV, indicative of its high colloidal stability. The release kinetics of the drug-loaded nanocomposite was investigated at pH = 5.4 and 7.4, and the results showed a controlled and pH-sensitive release, with 97 % and 54 % QC released after 96 h, respectively. The mechanism of drug release was investigated via fitting the experimental release data to different kinetic models, and the best fitting were obtained for Korsmeyer–Peppas and Baker at pH 7.4 and 5.4, respectively. Significant cytotoxicity of the Qc-loaded nanocomposite on breast cancer model cells, MCF-7, was corroborated by flow cytometry and MTT assays. In addition, improved apoptotic cell death was attained due to the presence of g-C3N4 nanoparticles. Results support the high potential of the developed nanocomposite as a novel pH-responsive drug delivery system for cancer therapy.

Efficient sunlight-assisted degradation of organic dyes using V2O3/g-C3N4 nanocomposite catalyst

This study reports the synthesis of vanadium oxide (V2O3) and graphitic carbon nitride (g-C3N4) nanocomposite for simple sunlight-assisted degradation of Methylene Blue(MB) and Rhodamine B (RhB) dyes. Herein, the V2O3 and g-C3N4 are synthesized via hydrothermal and thermal decomposition techniques, respectively. X-ray diffraction (XRD) analysis confirms the formation of the rhombohedral and hexagonal structures of V2O3 and g-C3N4 in the nanocomposite, respectively, while scanning electron microscopy (SEM) reveals the sheet-like morphology of g-C3N4 and V2O3 nanoparticles. The optical band gap of the nanocomposite is estimated as 1.89 eV using a Tauc's plot generated from UV–Vis reflectance spectroscopy. The as-synthesized nanocomposite exhibits an excellent dye degradation efficacy displaying a 100 % degradation of RhB and 90 % degradation of MB dyes within 1 h of exposure to daylight. This performance is attributed to the synergistic effect of the V2O3/g-C3N4 nanocomposite wherein the composite benefits from the large surface area and high visible light adsorption of g-C3N4, combined with the active catalytic sites of the rhombohedral V2O3 structure, resulting in its high efficiency for photocatalytic dye degradation. Scavenger studies confirm the hydroxyl (.OH) radicals and oxygen (O2−.) radicals as the primary reactive species in the degradation process MB. Furthermore, the catalyst exhibited remarkable stability over three cycles of photocatalysis thus confirming its utility for real-time environmental remediation applications.

Eco-conscious nanofluids: exploring heat transfer performance with graphitic carbon nitride nanoparticles

Abstract The work explores the heat transfer capabilities of semiconducting graphitic carbon nitride (g-C3N4) nanofluids. Also, it presents a sustainable and eco-friendly method for synthesizing g-C3N4 nanoparticles using commercially available rice flour as a natural carbon precursor through hydrothermal treatment. The synthesized sample subjected to various characterizations, including analysis of their structure, morphology, thermal properties, and optical properties. The optical bandgap (2.66 eV) is deduced through Tauc plot analysis and reveals the semiconducting nature of the sample. The formation of g-C3N4 is confirmed by various spectroscopic techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), and Raman spectroscopy. Thermogravimetric analysis (TGA) demonstrates the nanoparticles’ excellent thermal stability up to 550 °C, indicating potential applications in heat transfer fluids. The investigation of concentration-dependent thermal diffusivity variation using the sensitive mode mismatched dual beam thermal lens technique highlights the potential of g-C3N4 semiconductor nanofluid as an organic and metal-free additive in industry-demanding coolant applications.

Peroxymonosulfate-assisted photocatalytic degradation of rhodamine B by g-C3N4 nanoparticles modified with NiO cubes

Herein, NiO cubes with {100} facets or NiO trapezohedrons with {311} facets modified graphite carbon nitride (g-C3N4) nanoparticles acidified by HCl (HCN) were fabricated to form a p-n heterojunction (NiO/HCN) for the first time. These were further used for the degradation of rhodamine B (RhB) in water. 8-{100}NiO/HCN exhibited the highest degradation efficiency of 98.56% in just 60 min within peroxymonosulfate (PMS) under visible light. It was 2.51% higher than that of 8-{311} NiO/HCN. A series of characterization and experimental results showed that introducing {100} NiO could improve both the photocatalysis and PMS activation efficiency of the g-C3N4 compared with {311} NiO. The influence of environmental parameters on RhB degradation was systematically studied as well. Stability experiments demonstrated that 8-{100}NiO/HCN maintained high catalytic performance over a period of 10 h. The degradation mechanism behind PMS activation under visible light involved several factors: the unique micron-nano interface structure, electron (e-) transfer between NiO and g-C3N4, as well as effective facilitation of PMS activation by Ni2+. These factors led to the formation of singlet oxygen (1O2), which contributed significantly to RhB degradation. Overall, this work highlights how facet design can be utilized in metal oxide cocatalysts to improve photocatalytic degradation performance.

A novel biogenic method to synthesis a ternary (ZnO-Ag)/g-C3N4 nanocomposite with an enhanced photocatalytic and antibacterial activities

One of the most effective ways to obtain high-efficiency photocatalysts is to create heterojunctions between two semiconductors with matched band structures. As a pioneering photocatalytic system, the S-scheme heterojunction system has demonstrated considerable promise in simplifying the separation and transfer of photogenerated carriers as well as developing high photoredox capacity. Hence, we report a novel biogenic method to synthesise ternary (ZnO-Ag)/g-C3N4 S-scheme nanocomposites via Terminalia Arjuna leaf extract as an effective reducing and capping agent. The X-ray diffraction technique gives the structural confirmation of well-crystalline Ag, g-C3N4, and ZnO nanoparticles, indicating the excellent reducing property of Terminalia Arjuna leaf extract. UV-Vis spectroscopy reveals the enhanced optical behaviour of (ZnO-Ag)/g-C3N4 by means of a reduction in their bandgap values, which would reflect in the photocatalytic performance of the material. The presence of secondary meltabilities such as phenolic compounds, alkaloids, terpenoids, and proteins in leaf extract employed in the nucleation and stability of (ZnO-Ag)/g-C3N4 nanocomposites was analysed using FTIR spectroscopy. XPS rules out the presence of any other secondary elements(impurity). The incorporation of silver metal in ZnO nanomaterials was investigated using TEM analysis. Finally, the photocatalytic activity and antibacterial activity of (ZnO-Ag)/g-C3N4 nanocomposites were compared with the pristine Ag-ZnO, g-C3N4, and ZnO nanoparticles.