Synthesis of novel nanoflowers-like P, K co-doped graphitic carbon nitride for efficient H2O2 photoproduction.

Photocatalytic oxygen reduction is considered an economical and green way to produce H2O2. Graphitic carbon nitride is a common photocatalyst, but its activity is limited by the low specific surface area and the high recombination rate of photogenerated electron-hole pairs. Herein, nanoflowers-like phosphorus (P) and potassium (K) co-doped graphitic carbon nitride (PKCN) is synthesized by co-polymerization of ammonium dihydrogen phosphate and melamine in the mixed molten salt (KCl/LiCl) medium. Within 90 min, the synthesized PKCN-0.05 can produce 4.97 mmol L-1 of H2O2, which is 7.8 times higher than that of pure bulk g-C3N4. The enhanced photocatalytic performance of PKCN-0.05 is mainly attributed to the following: 1) KCl/LiCl molten salt induces melamine to form a three-dimensional flower-like morphology, which expands the specific surface area, exposes more active sites, and improves the light utilization efficiency; 2) high crystallinity of PKCN-0.05 and the K ions inserted between the interlayers are beneficial for accelerating electron transfer; 3) the formation of PN bonds and the existence of N vacancies promotes the separation of photoproduced carriers; 4) the negatively shifted conduction band of PKCN-0.05 favors oxygen reduction.

Alkali metal cation adsorption-induced surface polarization in polymeric carbon nitride for enhanced photocatalytic hydrogen peroxide production.

Photocatalytic hydrogen peroxide (H2O2) generation on the catalyst surface from oxygen is an electron-demanding process, making the construction of an electron-rich surface highly advantageous. In this study, a localized electric field was observed on the surface of polymeric carbon nitride (g-C3N4) when alkali metal cations were adsorbed onto it. These fields effectively inhibited surface carrier recombination and extended their lifespan, thereby enhancing H2O2 production. As a result, g-C3N4 achieved a superior H2O2 yield of 2.25 mM after 1 h in a 0.25 M K+ solution, which was 2.06 times greater than that (1.09 mM) achieved in a pure solvent. Notably, the increase in photocatalytic efficiency showed a remarkable dependence on ion species. At low concentrations, H2O2 generation efficiency was in the order of Li+ < Na+ < K+ < Rb+ < Cs+. However, after optimizing the ion concentration, the highest H2O2 production was achieved in a solution containing K+ instead of Cs+. Molecular dynamics simulations and temperature-dependent photocatalysis experiments revealed that the synergistic interaction between adsorption energy and adsorption distance was crucial in governing the extent to which alkali metal cation adsorption enhanced g-C3N4 photocatalytic H2O2 production. This study provides theoretical insights for the design of materials for electron-demanding photocatalysis and aids in understanding variations in photocatalytic behavior in natural waters.

SERS activity of silver nanoparticles and silver-modified 2D graphitic carbon nitride towards ciprofloxacin drug.

Herein, silver nanoparticles (AgNPs) and silver-loaded graphitic carbon nitride (Ag@g-C3N4) nanocomposites have been synthesized and used as an effective surface-enhanced Raman scattering (SERS) substrates for the detection of low concentrations (10-14 M) of ciprofloxacin (CIP), a commonly bioactive medication used to treat bacterial illnesses. A combined approach of vibrational spectroscopy and density functional theory (DFT) has been developed to understand the possible modes of analyte (CIP) and SERS substrate (AgNPs and Ag@g-C3N4) interactions. Furthermore, it has been noticed that the behavior of drug molecules in terms of SERS response and energetics of interaction changed significantly when interacted with the noble metal AgNPs decorated onto the g-C3N4 framework in comparison to only AgNPs as substrate. The most prominent interaction scenario between AgNPs and CIP is likely to be through the -NH moiety of drug molecule with an interaction energy of -306 kcal/mol. Whereas, the CIP molecules adsorbed onto Ag@g-C3N4 nanocomposite were more flexible with interaction energy of -107 kcal/mol, suggesting a greater association of analyte with the skeletal modes of substrate leading to Raman enhancements in the low wavenumber region i.e. below 600 cm-1. Hence, the Ag@g-C3N4 nanocomposite-based SERS substrates investigated served two distinct spectral ranges, making them complementary of each other in terms of SERS detection of CIP. The characteristics of the computed frontier molecular orbitals indicated a pronounced amount of charge transfer between the drug and the substrate, highlighting the significance of the chemical mechanism of the overall process. These results represent a successful approach to have an extended spectral range that covers lower wavenumber shifts by applying simple and meaningful modifications to the normally utilized noble metal-based nanoparticles, which can lead to more effective and reliable detection of bioactive drugs.

Design of novel Z-scheme g-C3N4/TiO2/CuCo2O4 heterojunctions for efficient visible light-driven photocatalyic degradation of rhodamine B.

One of the most important environmental challenges that needs to be resolved is the industrial discharge of synthetic dyes. Graphitic carbon nitride (g-C3N4), Titanium dioxide (TiO2) and flower-like copper oxide (CuO)/copper cobaltite (CuCo2O4) nanocomposites were synthesized in order to synthesis an effective visible light driven photocatalyst that could degrade Rhodamin B (Rh.B) dye under simulated solar light irradiation. The SEM and TEM results verifies that the flower-like CuO/CuCo2O4 (CCO) structure and g-C3N4/TiO2 (g-CN/TO) generated a smart hybrid structure with superior g-CN distribution. According to the photocatalytic studies, g- C3N4/TiO2/CuO/CuCo2O4 (g-CN/TO/CCO) shows good photodegradation of Rh.B dye (99.9%) in minmal times (1 h) in CCO: g-CN/TO (2:1) ratio by Z-Scheme mechanism. The enhanced visible light absorption and effective electron-hole pair separation provided by the synergistic dispersion of CuO/CuCo2O4 and g-C3N4 can be attributed to the improved photocatalytic performances. These novel insights into g-CN/TO/CCO based photocatalysts are useful for treating industrial effluent.

Building Asymmetric Zn-N3 Bridge between 2D Photocatalyst and Co-catalyst for Directed Charge Transfer toward Efficient H2O2 Synthesis.

Two-dimensional (2D) polymeric semiconductors are a class of promising photocatalysts; however, it remains challenging to facilitate their interlayer charge transfer for suppressed in-plane charge recombination and thus improved quantum efficiency. Although some strategies, such as π-π stacking and van der Waals interaction, have been developed so far, directed interlayer charge transfer still cannot be achieved. Herein, we report a strategy of forming asymmetric Zn-N3 units that can bridge nitrogen (N)-doped carbon layers with polymeric carbon nitride nanosheets (C3N4-Zn-N(C)) to address this challenge. The symmetry-breaking Zn-N3 moiety, which has an asymmetric local charge distribution, enables directed interfacial charge transfer between the C3N4 photocatalyst and the N-doped carbon co-catalyst. As evidenced by femtosecond transient absorption spectroscopy, charge separation can be significantly enhanced by the interfacial asymmetric Zn-N3 bonding bridges. As a result, the designed C3N4-Zn-N(C) catalyst exhibits dramatically enhanced H2O2 photosynthesis activity, outperforming most of the reported C3N4-based catalysts. This work highlights the importance of tailoring interfacial chemical bonding channels in polymeric photocatalysts at the molecular level to achieve effective spatial charge separation.

In-situ Monitoring of Photocatalysis on Polymeric Carbon Nitride Thin Films.

Polymeric carbon nitride has attracted significant interest in heterogeneous photocatalysis due to its activity under visible-light irradiation. Herein, we report on using carbon nitride-coated NMR tubes for in-situ studies of photocatalytic reaction mechanisms. In a first step, we exploited carbon nitride-coated crimp vials as batch photoreactors for visible photocatalytic fluorinations of unactivated C(sp3)-H bonds, with moderate to excellent yields and reusability over multiple cycles. Eventually, carbon nitride-coated NMR tubes were used as a photoreactor by coupling them with optical fiber irradiation directly inside the spectrometer. This enabled us to follow the reaction with in-situ NMR spectroscopy identifying reactive intermediates otherwise elusive in conventional analyses. The method provides advantages for the study of photocatalytic mechanisms of complex reactions and substantially reduces the need of comparative tests for depicting reaction intermediates and conversion pathways.

Alginate/CuO-gC3N4 composite: a novel, reusable, non-toxic photocatalyst for methylene blue degradation.

Increasing industrial contamination necessitates development of sustainable water treatment solutions. Photocatalysis is a green technology utilizing light-activated materials (photocatalysts), which can degrade pollutants into harmless by-products. It is an emergent need to develop a photocatalyst that presents a significant advancement for sustainable water treatment and non-toxic to the environment. This study investigates the photocatalytic activity and in vitro cytotoxicity of a novel hybrid material comprising of alginate, copper oxide (CuO) and graphitic carbon nitride (gC3N4) for methylene blue (MB) degradation. The hybrid material was synthesized by a two-step process: (i) doping of CuO on gC3N4 through co-precipitation method formed CuO-gC3N4 (CG) and (ii) incorporation of CG in the calcium alginate (A) by ionotropic gelation method that is named as ACG. The characteristic features of the synthesized A, CG and ACG were studied using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The optical characteristic of A, CG and ACG was studied using UV-diffuse reflectance spectroscopy (UV-DRS). The morphology and elemental composition of ACG was evaluated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). To assess the environmental impact of ACG, a two-step approach was employed. First, the photocatalytic activity of ACG under UV-visible light (UV-vis) irradiation for MB degradation was evaluated. ACG exhibited photocatalytic activity by achieving 86.26% of degradation efficiency for MB within 60 min. Second, the in vitro cytotoxicity of ACG, MB and MB degraded products towards tilapia gill cell lines were assessed. By comparing the toxicity of the MB and the secondary products, it is concluded that the overall process leads to a sustainable outcome.

A photoelectrochemical aptasensor based on W6+-doped carbon nitride with carbon-rich structure for sensitive detection of diazinon.

A photoelectrochemical (PEC) aptasensor us reported based on W6+-doped carbon nitride with carbon-rich structure (WCCN). WCCN exhibited excellent photoelectric conversion performance owing to the carbon-rich structure and W6+ doping. C atoms can replace the center N/edge N atoms to form a carbon-rich structure, improving the insufficient light absorption of CN in the visible region. Also, W6+ doping forms a directional electron transfer channel, achieving the efficient separation and transport of carriers. W6+ doping and carbon-rich structure can promote the generation, transfer, and separation of photogenerated carriers, further enhancing PEC performance. The fabricated PEC aptasensor based on WCCN demonstrated a wide detection range (3.92 ~ 588 pg L-1), a low detection limit (1.31 pg L-1, S/N = 3), good reproducibility, selectivity, stability, and practical application in actual water samples. This work explores the modification strategy of element doping for carbon nitride with high photoelectric property and offers a cost-effective and simplified method for the detection of pesticide residues.

Nanoarchitectonics of vanadium nanoparticles decorated mesoporous carbon nitride in photocatalytic systems: A study on ethylbenzene oxidation reaction.

In this work, we have described the synthesis of vanadium (V) nanoparticles (NPs) anchored on mesoporous graphitic carbon nitride (V@mpg-C3N4) and their uses in photocatalytic ethylbenzene oxidation to the respective acetophenones. The mpg-C3N4 serves as the support for the decoration of V NPs, through a simple impregnation method. Various advanced techniques, such as XRD, UV-vis spectrometry, HRTEM, HAADF-STEM, AC-STEM, elemental mapping, and BET surface area analysis, were employed for the characterization of V@mpg-C3N4. The detailed characterization studies reveal that the V@mpg-C3N4 catalyst has a medium band gap (2.78 eV), a high surface area (76.7 m2g-1), and a mesoporous nature. The V@mpg-C3N4 photocatalysts demonstrated excellent performance in the light-assisted oxidation of ethylbenzene, achieving over 99 % conversion and selectivity for acetophenone in an environmentally friendly solvent (water) using a domestic light source (50 W white light). This developed synthesis strategy will be useful for synthesizing various noble and non-noble metal-based catalysts and their applications in organic transformation and environmental remediation.

S-Modified Graphitic Carbon Nitride with Double Defect Sites For Efficient Photocatalytic Hydrogen Evolution.

Graphitic carbon nitride (gC3N4) is an attractive photocatalyst for solar energy conversion due to its unique electronic structure and chemical stability. However, gC3N4 generally suffers from insufficient light absorption and rapid compounding of photogenerated charges. The introduction of defects and atomic doping can optimize the electronic structure of gC3N4 and improve the light absorption and carrier separation efficiency. Herein, the high efficiency of carbon nitride photocatalysis for hydrogen evolution in visible light is achieved by an S-modified double-deficient site strategy. Defect engineering forms abundant unsaturated sites and cyano (─C≡N), which promotes strong interlayer C─N bonding interactions and accelerates charge transport in gC3N4. S doping tunes the electronic structure of the semiconductors, and the formation of C─S─C bonds optimizes the electron-transfer paths of the C─N bonding, which enhances the absorption of visible light. Meanwhile,C≡N acts as an electron trap to capture photoexcited electrons, providing the active site for the reduction of H+ to hydrogen. The photocatalytic hydrogen evolution efficiency of SDCN (1613.5 µmol g-1 h-1) is 31.5 times higher than that of pristine MCN (51.2 µmol g-1 h-1). The charge separation situation and charge transfer mechanism of the photocatalysts are investigated in detail by a combination of experimental and theoretical calculations.

Oxygen-doped Porous Ultrathin Graphitic Carbon Nitride Nanosheets for Photocatalytic Hydrogen Evolution and Rhodamine B Degradation.

Graphite phase carbon nitride (g-C3N4) is a highly promising metal-free photocatalyst. However, its applicability is restricted by low activity, due to weak quantum efficiency and small specific surface area. Exfoliating bulk crystals into porous thin-layer nanosheets and introducing element doping have been shown to improve photocatalytic efficiency, but these methods are often complex, time-consuming, and costly processes. In this study, we successfully synthesized porous oxygen-doped g-C3N4 (OCN) nanosheets utilizing a straightforward method. Our findings show that OCN have much higher light absorption and visible-light photocatalytic activity than bulk g-C3N4 (BCN) and nonporous g-C3N4 (CN). The OCN photocatalyst has a remarkable hydrogen evolution reaction (HER) rate of 8.02 mmol·g-1 h-1, which is 8 times greater than BCN. Additionally, the OCN shows a high degradation rate of 97.3% for Rhodamine B (RhB). This enhanced photocatalytic activity is ascribed to the narrow band gap and superior electron transfer capacity. Our findings suggest a potential technique for generating efficient g-C3N4 photocatalysts.

Construction of a In2O3/ultrathin g-C3N4 S-scheme heterojunction for sensitive photoelectrochemical aptasensing of diazinon.

A single semiconductor-based photoelectrochemical (PEC) aptasensor usually faces a challenge of low sensitivity due to poor solar energy utilization and a high photogenerated carrier recombination rate. Herein, an ultra-thin carbon nitride nanosheet-coated In2O3 (In2O3/CNS) S-type heterojunction-based PEC aptasensor has been established to achieve highly sensitive detection of diazinon (DZN) pesticide in water environment. Construction of S-type heterojunction induces a band shift and an electric field effect, enhancing light utilization and accelerating directional transmission of carriers, leading to outstanding PEC performance. The creation of internal electric field at interface ensures stable carrier transport. Additionally, ultrathin CNS structure can effectively shorten the transport path of carriers. The close coating of In2O3 and CNS promotes the transfer of charge. The synergistic effects amplify the sensor's response, ultimately enabling the effective detection of DZN residue over a wide detection range (0.98 âˆ¼ 980.0 pg mL-1), a low detection limit (0.33 pg mL-1, S/N = 3) and excellent accuracy in practical application (RSD < 5 %). This work provides a reference for the construction of a new S-type heterojunction-based PEC sensor.

Carbon-Based Materials in Combined Adsorption/Ozonation for Indigo Dye Decolorization in Constrain Contact Time.

This study presents a comprehensive evaluation of catalytic ozonation as an effective strategy for indigo dye bleaching, particularly examining the performance of four carbon-based catalysts, activated carbon (AC), multi-walled carbon nanotubes (MWCNT), graphitic carbon nitride (g-C3N4), and thermally etched nanosheets (C3N4-TE). The study investigates the efficiency of catalytic ozonation in degrading Potassium indigotrisulfonate (ITS) dye within the constraints of short contact times, aiming to simulate real-world industrial wastewater treatment conditions. The results reveal that all catalysts demonstrated remarkable decolorization efficiency, with over 99% of indigo dye removed within just 120 s of mixing time. Besides, the study delves into the mechanisms underlying catalytic ozonation reactions, elucidating the intricate interactions between the catalysts, ozone, and indigo dye molecules with the processes being influenced by factors such as PZC, pKa, and pH. Furthermore, experiments were conducted to analyze the adsorption characteristics of indigo dye on the surfaces of the materials and its impact on the catalytic ozonation process. MWCNT demonstrated the highest adsorption efficiency, effectively removing 43.4% of the indigo dye color over 60 s. Although the efficiency achieved with C3N4-TE was 21.4%, which is approximately half of that achieved with MWCNT and less than half of that with AC, it is noteworthy given the significantly lower surface area of C3N4-TE.

Polyaniline/graphitic carbon nitride/reduced graphene oxide ternary nanocomposite film for flexible thermoelectric application.

The present study outlines the preparation of a ternary nanocomposite film comprising of polyaniline doped with camphor sulfonic acid (PANI), reduced graphene oxide (rGO), and graphitic carbon nitride (g-C3N4), and delves into its thermoelectric performance. PANI is known to possess high electrical conductivity (σ) and poor thermal conductivity (κ). However, its potential for thermoelectric applications is constrained by the low value of the Seebeck coefficient (S). The incorporation of g-C3N4in PANI has been demonstrated to result in an improvement of the Seebeck coefficient. Furthermore, the addition of rGO to the PANI/g-C3N4sample counteracts the decrease in electrical conductivity. The PANI/g-C3N4/rGO ternary nanocomposite film exhibits an enhanced Seebeck coefficient of ∼2.2 times when compared to the PANI sample. The Seebeck coefficient of the PANI/g-C3N4/rGO nanocomposite is enhanced by the energy filtering effect that occurs at the interfaces between g-C3N4/PANI and PANI/rGO. Theπ-πinteraction between the PANI chains and rGO is responsible for the increased electrical conductivity resulting from the well-ordered polymer chain arrangement on the g-C3N4and rGO surfaces. The ternary nanocomposite sample demonstrated a synergistic improvement in both electrical conductivity and Seebeck coefficient, resulting in a remarkable ∼4.6-fold increment in power factor and an ∼4.3-fold enhancement in the figure of merit (zT), as compared to the pristine PANI film.

Carbon Nitride Nanosheets as an Adhesive Layer for Stable Growth of Vertically-Ordered Mesoporous Silica Film on a Glassy Carbon Electrode and Their Application for CA15-3 Immunosensor.

Vertically ordered mesoporous silica films (VMSF) are a class of porous materials composed of ultrasmall pores and ultrathin perpendicular nanochannels, which are attractive in the areas of electroanalytical sensors and molecular separation. However, VMSF easily falls off from the carbonaceous electrodes and thereby impacts their broad applications. Herein, carbon nitride nanosheets (CNNS) were served as an adhesive layer for stable growth of VMSF on the glassy carbon electrode (GCE). CNNS bearing plentiful oxygen-containing groups can covalently bind with silanol groups of VMSF, effectively promoting the stability of VMSF on the GCE surface. Benefiting from numerous open nanopores of VMSF, modification of VMSF's external surface with carbohydrate antigen 15-3 (CA15-3)-specific antibody allows the target-controlled transport of electrochemical probes through the internal silica nanochannels, yielding sensitive quantitative detection of CA15-3 with a broad detection range of 1 mU/mL to 1000 U/mL and a low limit of detection of 0.47 mU/mL. Furthermore, the proposed VMSF/CNNS/GCE immunosensor is capable of highly selective and accurate determination of CA15-3 in spiked serum samples, which offers a simple and effective electrochemical strategy for detection of various practical biomarkers in complicated biological specimens.

Dual-Mechanism Quenching Electrochemiluminescence System by Coupling Energy Transfer with Electron Transfer for Sensitive Competitive Aptamer-Based Detection of Furanyl Fentanyl in Food.

Resonance energy transfer (RET) quenching is significantly important for developing electrochemiluminescence (ECL) sensors, but RET platforms face challenges like interference from other fluorescent substances and reliance on energy transfer efficiency. This study used Zn-PTC, formed by zinc ions coordinated with perylene-3,4,9,10-tetracarboxylate, as a dual-mechanism quencher to reduce the ECL intensity of carbon nitride nanosheets (Tg-CNNSs). Co3O4/NiCo2O4 acts as a coreaction promoter, enhancing and stabilizing the luminescence of Tg-CNNSs. Zn-PTC absorbs energy from Tg-CNNSs, altering the fluorescence lifetime to confirm energy transfer, while energy-level matching demonstrates electron transfer. By leveraging both RET and electron transfer mechanisms, the designed ECL aptasensor significantly reduces signal fluctuations that may arise from a single mechanism, resulting in more stable and reliable detection outcomes. The ECL aptasensor designed for furanyl fentanyl (FUF) detection shows excellent performance with a detection limit of 5.7 × 10-15 g/L, offering new pathways for detecting FUF and other small molecules.

Boron-doped sulfonated graphitic carbon nitride as a highly efficient catalyst for the production of 5-hydroxymethylfurfural from carbohydrates.

The presence of humins during the conversion of concentrated fructose presents a major obstacle in the large-scale production of 5-hydroxymethylfurfural (HMF) from fructose. Herein, we reported a boron-doped graphitic carbon nitride sulfonated (BGCN-SO3H) as an excellent catalyst for the synthesis of HMF from fructose. The BGCN-SO3H catalyst structures were analyzed using various characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), elemental mapping analysis, and Fourier-transform infrared spectroscopy (FT-IR). The BGCN-SO3H catalyst was evaluated for the synthesis of HMF from fructose. We investigated the influence of catalyst performance, including solvent reactions, catalyst loading, substrates, and volume of solvent to optimize reaction conditions. As a result, the yield of HMF was obtained at 88 % within 5 h when using 30 mg of catalyst. The study of catalyst activity involved examining reactions that allowed recovery and reuse. The research findings offer a method for producing HMF with exceptional efficiency using solid catalysts.

Utilization of Water-Insoluble Carbon Nitride-Phosphotungstic Acid Hybrids in Composite Proton Exchange Membranes.

Phosphotungstic acid (HPW) can retain water in proton exchange membranes to increase proton conductivity; however, its water-soluble nature limits further application. In this work, we combined HPW and graphitic carbon nitride (g-C3N4) via sintering to prepare water-insoluble hybrids (HWN), where HPW was chemically linked to g-C3N4 to fix HPW. Then, HWN fillers were added to a sulfonated polyether ether ketone (SPEEK) matrix to prepare composite membranes. The conductivity of the composite membrane with 10 wt% HWN is up to 0.066 S cm-1 at room temperature, which is 53% higher than that of the SPEEK control membrane (0.043 S cm-1). The composite membrane also showed stable proton conductivity after being immersed in water for 2000 h. Therefore, our study demonstrates that preparing water-insoluble nanofillers containing HPW components through sintering is a promising approach.

Ultrathin-N2C-Deficient Carbon Nitride for Stabilized Enhancement of Electrochemiluminescence.

In the realm of electrochemiluminescence (ECL), the issue of weak signal intensity and instability linked with pure graphitic carbon nitride (CN) is widely recognized. This study suggests a method to produce nitrogen-deficient (N2C) porous ultrathin CN (UACN) using ammonium acetate and ultrasonication. The ultrathin porous nature of UACN provides numerous N2C defects as catalytic sites, aiding in the decomposition of K2S2O8, a conclusion supported by density functional theory (DFT). Importantly, N2C defects serve as electron traps, assisting in electron localization and enhancing the recombination of electron-hole pairs, thereby achieving stable and intensified luminescence from UACN. In practical use, UACN, acting as an ECL emitter, is utilized in detecting the tumor marker carcinoembryonic antigen (CEA), effectively establishing a highly sensitive immunosensing platform. This study elucidates the correlation between UACN structure and ECL performance, offering crucial insights for comprehending ECL mechanisms and designing high-performance ECL materials.

Natural deep eutectic solvent-functionalized mesoporous graphitic carbon nitride-reinforced electrospun nanofiber: a promising sorbent in miniaturized on-chip thin film micro-solid-phase extraction prior to liquid chromatography-tandem mass spectrometry for measuring NSAIDs in saliva.

To meet the needs of developing efficient extractive materials alongside the evolution of miniaturized sorbent-based sample preparation techniques, a mesoporous structure of g-C3N4 doped with sulfur as a heteroatom was achieved utilizing a bubble template approach while avoiding the severe conditions of other methods. In an effort to increase the number of adsorption sites, the resultant exfoliated structure was then modified with thymol-coumarin NADES as a natural sorbent modifier, followed by introduction into a nylon 6 polymer via an electrospinning process. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) surface area analysis validated S-doped g-C3N4 and composite production. The prepared electrospun fiber nanocomposite, entailing satisfactory processability, was then successfully utilized as a sorbent in on-chip thin film micro-solid-phase extraction of non-steroidal anti-inflammatory drugs (NSAIDs) from saliva samples prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Utilizing a chip device, a thin film µ-SPE coupled with LC-MS/MS analysis yielded promising outcomes with reduced sample solution and organic solvents while extending lifetime of a thin film sorbent. The DES-modified S-doped g-C3N4 amount in electrospun was optimized, along with adsorption and desorption variables. Under optimal conditions, selected NSAIDs were found to have a linear range of 0.05-100.0 ng mL-1 with an R2 ≥ 0.997. The detection limits were ranged between 0.02 and 0.2 ng mL-1. The intra-day and inter-day precisions obtained were less than 6.0%. Relative recoveries were between 93.3 and 111.4%.