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1.
Nano Lett ; 24(15): 4439-4446, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38498723

RESUMO

Graphitic carbon nitrides (g-C3N4) as low-cost, chemically stable, and ecofriendly layered semiconductors have attracted rapidly growing interest in optoelectronics and photocatalysis. However, the nature of photoexcited carriers in g-C3N4 is still controversial, and an independent charge-carrier picture based on the band theory is commonly adopted. Here, by performing transient spectroscopy studies, we show characteristics of self-trapped excitons (STEs) in g-C3N4 nanosheets including broad trapped exciton-induced absorption, picosecond exciton trapping without saturation at high photoexcitation density, and transient STE-induced stimulated emissions. These features, together with the ultrafast exciton trapping polarization memory, strongly suggest that STEs intrinsically define the nature of the photoexcited states in g-C3N4. These observations provide new insights into the fundamental photophysics of carbon nitrides, which may enlighten novel designs to boost energy conversion efficiency.

2.
Small ; 20(14): e2306983, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37988639

RESUMO

Constructing S-scheme heterojunction catalysts is a key challenge in visible-light catalysed degradation of organic pollutants. Most heterojunction materials are reported to face significant obstacles in the separation of photogenerated electron-hole pairs owing to differences in the material size and energy barriers. In this study, sulfur-doped g-C3N4 oxidative-type semiconductor materials are synthesized and then coupled with BiOBr reductive-type semiconductor to form S-g-C3N4/BiOBr S-scheme heterojunction. A strong and efficient internal electric field is established between the two materials, facilitating the separation of photogenerated electron-hole pairs. Notably, in situ XPS proved that after visible light irradiation, Bi3+ is converted into Bi(3+ɑ)+, and a large number of photogenerated holes are produced on the surface of BiOBr, which oxidized and activated H2O into •OH.  â€¢OH cooperated with •O2 - and 1O2 to attack Rhodamine B (RhB) molecules to achieve deep oxidation mineralization. The composite material is designed with a LUMO energy level higher than that of RhB, promoting the sensitization of RhB by injecting photogenerated electrons into the heterojunction, thereby enhancing the photocatalytic performance to 22.44 times that of pure g-C3N4. This study provides a new perspective on the efficient degradation of organic molecules using visible light catalysis.

3.
Small ; : e2400724, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38639018

RESUMO

The lack of intrinsic active sites for photocatalytic CO2 reduction reaction (CO2RR) and fast recombination rate of charge carriers are the main obstacles to achieving high photocatalytic activity. In this work, a novel phosphorus and boron binary-doped graphitic carbon nitride, highly porous material that exhibits powerful photocatalytic CO2 reduction activity, specifically toward selective CO generation, is disclosed. The coexistence of Lewis-acidic and Lewis-basic sites plays a key role in tuning the electronic structure, promoting charge distribution, extending light-harvesting ability, and promoting dissociation of excitons into active carriers. Porosity and dual dopants create local chemical environments that activate the pyridinic nitrogen atom between the phosphorus and boron atoms on the exposed surface, enabling it to function as an active site for CO2RR. The P-N-B triad is found to lower the activation barrier for reduction of CO2 by stabilizing the COOH reaction intermediate and altering the rate-determining step. As a result, CO yield increased to 22.45 µmol g-1 h-1 under visible light irradiation, which is ≈12 times larger than that of pristine graphitic carbon nitride. This study provides insights into the mechanism of charge carrier dynamics and active site determination, contributing to the understanding of the photocatalytic CO2RR mechanism.

4.
Small ; : e2404822, 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39096107

RESUMO

Selective photocatalytic CO2 reduction to high-value hydrocarbons using graphitic carbon nitride (g-C3N4) polymer holds great practical significance. Herein, the cyano-functionalized g-C3N4 (CN-g-C3N4) with a high local electron density site is successfully constructed for selective CO2 photoreduction to CH4 and C2H4. Wherein the potent electron-withdrawing cyano group induces a giant internal electric field in CN-g-C3N4, significantly boosting the directional migration of photogenerated electrons and concentrating them nearby. Thereby, a high local electron density site around its cyano group is created. Moreover, this structure can also effectively promote the adsorption and activation of CO2 while firmly anchoring *CO intermediates, facilitating their subsequent hydrogenation and coupling reactions. Consequently, using H2O as a reducing agent, CN-g-C3N4 achieves efficient and selective photocatalytic CO2 reduction to CH4 and C2H4 activity, with maximum rates of 6.64 and 1.35 µmol g-1 h-1, respectively, 69.3 and 53.8 times higher than bulk g-C3N4 and g-C3N4 nanosheets. In short, this work illustrates the importance of constructing a reduction site with high local electron density for efficient and selective CO2 photoreduction to hydrocarbons.

5.
Small ; : e2404696, 2024 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-39155427

RESUMO

Graphitic carbon nitride (g-C3N4) is a prominent photocatalyst that has attracted substantial interest in the field of photocatalytic environmental remediation due to the low cost of fabrication, robust chemical structure, adaptable and tunable energy bandgaps, superior photoelectrochemical properties, cost-effective feedstocks, and distinctive framework. Nonetheless, the practical application of bulk g-C3N4 in the photocatalysis field is limited by the fast recombination of photogenerated e--h+ pairs, insufficient surface-active sites, and restricted redox capacity. Consequently, a great deal of research has been devoted to solving these scientific challenges for large-scale applications. This review concisely presents the latest advancements in g-C3N4-based photocatalyst modification strategies, and offers a comprehensive analysis of the benefits and preparation techniques for each strategy. It aims to articulate the complex relationship between theory, microstructure, and activities of g-C3N4-based photocatalysts for atmospheric protection. Finally, both the challenges and opportunities for the development of g-C3N4-based photocatalysts are highlighted. It is highly believed that this special review will provide new insight into the synthesis, modification, and broadening of g-C3N4-based photocatalysts for atmospheric protection.

6.
Small ; 20(22): e2308568, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38126907

RESUMO

In this work, cyano contained g-C3N4 comodified by In2S3 and polypyrrole (C≡N─CN/IS/Ppy) materials are synthesized for the photocatalytic production of H2O2 and photocatalysis-self-Fenton reaction for highly efficient degradation of metronidazole. The results from UV-vis spectrophotometry, surface photovoltage, and Kelvin probe measurements reveal the promoted transport and separation efficiency of photoinduced charges after the introduction of In2S3 and Ppy in the heterojunction. The existence of a built-in electric field accelerates the photoinduced charge separation and preserves the stronger oxidation ability of holes at the valence band of C≡N─CN. Linear sweep voltammetry measurements, zeta potential analyzations, nitroblue tetrazolium determination, and other measurements show that Ppy improves the conversion ratio of •O2 - to H2O2 and the utilization ratio of •O2 -, as well as suppresses decomposition of H2O2. Accordingly, the H2O2 evolution rate produced via a two-step single-electron reduction reaction reaches almost 895 µmol L-1 h-1, a value 80% and 7.2-fold higher than those obtained with C≡N─CN/IS and C≡N─CN, respectively. The metronidazole removal rate obtained via photocatalysis-self-Fenton reaction attains 83.7% within 120 minutes, a value much higher than that recorded by the traditional Fenton method. Overall, the proposed synthesis materials and route look promising for the H2O2 production and organic pollutants degradation.

7.
Small ; 20(29): e2311841, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38368255

RESUMO

Heterostructures are widely employed in photocatalysis to promote charge separation and photocatalytic activity. However, their benefits are limited by the linkages and contact environment at the interface. Herein, violet phosphorus quantum dots (VPQDs) and graphitic carbon nitride (g-C3N4) are employed as model materials to form VPQDs/g-C3N4 heterostructures by a simple ultrasonic pulse excitation method. The heterostructure contains strong interfacial P-N bonds that mitigate interfacial charge-separation issues. P-P bond breakage occurs in the distinctive cage-like [P9] VPQD units during longitudinal disruption, thereby exposing numerous active P sites that bond with N atoms in g-C3N4 under ultrasonic pulse excitation. The atomic-level interfacial P-N bonds of the Z-scheme VPQDs/g-C3N4 heterostructure serve as photogenerated charge-transfer channels for improved electron-hole separation efficiency. This results in excellent photocatalytic performance with a hydrogen evolution rate of 7.70 mmol g-1 h-1 (over 9.2 and 8.5 times greater than those of pure g-C3N4 and VPQDs, respectively) and apparent quantum yield of 11.68% at 400 nm. Using atomic-level chemical bonds to promote interfacial charge separation in phosphorene heterostructures is a feasible and effective design strategy for photocatalytic water-splitting materials.

8.
Metabolomics ; 20(4): 77, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39014104

RESUMO

INTRODUCTION: Accurately identifying and quantifying polar metabolites using untargeted metabolomics has proven challenging in comparison to mid to non-polar metabolites. Hydrophilic interaction chromatography and gas chromatography-mass spectrometry are predominantly used to target polar metabolites. OBJECTIVES: This study aims to demonstrate a simple one-step extraction combined with liquid chromatography-mass spectrometry (LC-MS) that reliably retains polar metabolites. METHODS: The method involves a MilliQ + 10% trichloroacetic acid extraction from 6 healthy individuals serum, combined with porous graphitic carbon liquid chromatography-mass spectrometry (LC-MS). The coefficient of variation (CV) assessed retention reliability of polar metabolites with logP as low as - 9. QreSS (Quantification, Retention, and System Suitability) internal standards determined the method's consistency and recovery efficiency. RESULTS: The method demonstrated reliable retention (CV < 0.30) of polar metabolites within a logP range of - 9.1 to 5.6. QreSS internal standards confirmed consistent performance (CV < 0.16) and effective recovery (70-130%) of polar to mid-polar metabolites. Quality control dilution series demonstrated that ~ 80% of annotated metabolites could be accurately quantified (Pearson's correlation coefficient > 0.80) within their concentration range. Repeatability was demonstrated through clustering of repeated extractions from a single sample. CONCLUSION: This LC-MS method is better suited to covering the polar segment of the metabolome than current methods, offering a reliable and efficient approach for accurate quantification of polar metabolites in untargeted metabolomics.


Assuntos
Grafite , Metabolômica , Ácido Tricloroacético , Ácido Tricloroacético/química , Metabolômica/métodos , Humanos , Cromatografia Líquida/métodos , Grafite/química , Porosidade , Masculino , Espectrometria de Massas/métodos
9.
Chemistry ; 30(45): e202401675, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-38842477

RESUMO

Single atom catalysts (SACs) exhibit the flexible coordination structure of the active site and high utilization of active atoms, making them promising candidates for nitrogen reduction reaction (NRR) under ambient conditions. By the aid of first-principles calculations based on DFT, we have systematically explored the NRR catalytic behavior of thirteen 4d- and 5d-transition metal atoms anchored on 2D porous graphite carbon nitride C 5 ${_5 }$ N 2 ${_2 }$ . With high selectivity and outstanding activity, Zr, Nb, Mo, Ta, W and Re-doped C 5 ${_5 }$ N 2 ${_2 }$ are identified as potential nominees for NRR. Particularly, Mo@C 5 ${_5 }$ N 2 ${_2 }$ possesses an impressive low limiting potential of -0.39 V (corresponding to a very low temperature and atmospheric pressure), featuring the potential determining step involving *N-N transitions to *N-NH via the distal path. The catalytic performance of TM@C 5 ${_5 }$ N 2 ${_2 }$ can be well characterized by the adsorption strength of intermediate *N 2 ${_2 }$ H. Moreover, there exists a volcanic relationship between the catalytic property U L ${_{\rm{L}} }$ and the structure descriptor Ψ ${{{\Psi }}}$ , which validates the robustness and universality of Ψ ${{{\Psi }}}$ , combined with our previous study. This work sheds light on the design of SACs with eminent NRR performance.

10.
Chemistry ; : e202402662, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39166710

RESUMO

The photo-induced deoxygenative C2 arylation of quinoline N-oxides to 2-arylquinolines is achieved over a heterogeneous porous tubular graphitic carbon nitride (PTCN) catalyst with phenylhydrazines as arylation reagent. A wide range of quinoline N-oxides can be efficiently transformed into their corresponding 2-arylquinolines under visible light irradiation. Moreover, PTCN catalyst is easily separated and could be reused several times without loss to its original activity.

11.
Chemphyschem ; : e202400356, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39080833

RESUMO

On the basis of thermal etching bulk graphitic carbon nitride (g-C3N4), a mild hydrochloric acid treatment method was used in this work to produce g-C3N4 nano-sheets (CNNS) and further carbon nitride with chloride-modification (CNCl). The latter has thinner layer and smaller particle size and exhibit greatly improved dispersibility and solubility in water, DMSO and other polar solvents. A typical photocatalytic reaction in solution driven by CNCl shows a significantly improved photocatalytic performance over bulk g-C3N4 and CNNS. Steady-state analytical tools including SEM, mass, UV-Vis and IR spectroscopies, and time-resolved two-dimensional infrared (2D IR) vibrational spectroscopy, were used together in this work. Better solubility, more flexible structure, smaller size, easier generation of free radicals and lower recombination rate of electron-hole pair, are believed to be reasons for the superior photocatalytic performance of CNCl.

12.
Anal Bioanal Chem ; 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39158631

RESUMO

Liquid chromatography-mass spectrometry (LC-MS) has emerged as a powerful analytical technique for analyzing complex biological samples. Among various chromatographic stationary phases, porous graphitic carbon (PGC) columns have attracted significant attention due to their unique properties-such as the ability to separate both polar and non-polar compounds and their stability through all pH ranges and to high temperatures-besides the compatibility with LC-MS. This review discusses the applicability of PGC for SPE and separation in LC-MS-based analyses of human biological samples, highlighting the diverse applications of PGC-LC-MS in analyzing endogenous metabolites, pharmaceuticals, and biomarkers, such as glycans, proteins, oligosaccharides, sugar phosphates, and nucleotides. Additionally, the fundamental principles underlying PGC column chemistry and its advantages, challenges, and advances in method development are explored. This comprehensive review aims to provide researchers and practitioners with a valuable resource for understanding the capabilities and limitations of PGC columns in LC-MS-based analysis of human biological samples, thereby facilitating advancements in analytical methodologies and biomedical research.

13.
Macromol Rapid Commun ; : e2400365, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849126

RESUMO

Graphitic carbon nitrides (g-C3N4) possess various benefits as heterogeneous photocatalysts, including tunable bandgaps, scalability, and chemical robustness. However, their efficacy and ongoing advancement are hindered by challenges like limited charge-carrier separation rates, insufficient driving force for photocatalysis, small specific surface area, and inadequate absorption of visible light. In this study, boron dopants and nitrogen defects synergy are introduced into bulk g-C3N4 through the calcination of a blend of nitrogen-defective g-C3N4 and NaBH4 under inert conditions, resulting in the formation of BCN nanosheets characterized by abundant porosity and increased specific surface area. These BCN nanosheets promote intermolecular single electron transfer to the radical initiator, maintaining radical intermediates at a low concentration for better control of photoinduced atom transfer radical polymerization (photo-ATRP). Consequently, this method yields polymers with low dispersity and tailorable molecular weights under mild blue light illumination, outperforming previous reports on bulk g-C3N4. The heterogeneity of BCN enables easy separation and efficient reuse in subsequent polymerization processes. This study effectively showcases a simple method to alter the electronic and band structures of g-C3N4 with simultaneously introducing dopants and defects, leading to high-performance photo-ATRP and providing valuable insights for designing efficient photocatalytic systems for solar energy harvesting.

14.
Environ Res ; 244: 117964, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38135102

RESUMO

In this study, we evaluate the efficiency of two novel nanostructured adsorbents - chitosan-graphitic carbon nitride@magnetite (CS-g-CN@Fe3O4) and graphitic carbon nitride@copper/zinc nanocomposite (g-CN@Cu/Zn NC) - for the rapid removal of methylparaben (MPB) from water. Our characterization methods, aimed at understanding the adsorbents' structures and surface areas, informed our systematic examination of influential parameters including sonication time, adsorbent dosage, initial MPB concentration, and temperature. We applied advanced modeling techniques, such as response surface methodology (RSM), generalized regression neural network (GRNN), and radial basis function neural network (RBFNN), to evaluate the adsorption process. The adsorbents proved highly effective, achieving maximum adsorption capacities of 255 mg g-1 for CS-g-CN@Fe3O4 and 218 mg g-1 for g-CN@Cu/Zn NC. Through genetic algorithm (GA) optimization, we identified the optimal conditions for the highest MPB removal efficiency: a sonication period of 12.00 min and an adsorbent dose of 0.010 g for CS-g-CN@Fe3O4 NC, with an MPB concentration of 17.20 mg L-1 at 42.85 °C; and a sonication time of 10.25 min and a 0.011 g dose for g-CN@Cu/Zn NC, with an MPB concentration of 13.45 mg L-1 at 36.50 °C. The predictive accuracy of the RBFNN and GRNN models was confirmed to be satisfactory. Our findings demonstrate the significant capabilities of these synthesized adsorbents in effectively removing MPB from water, paving the way for optimized applications in water purification.


Assuntos
Grafite , Compostos de Nitrogênio , Parabenos , Poluentes Químicos da Água , Purificação da Água , Cobre/química , Temperatura , Água/química , Adsorção , Poluentes Químicos da Água/química , Cinética , Concentração de Íons de Hidrogênio , Purificação da Água/métodos
15.
Environ Res ; 257: 119293, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38838749

RESUMO

Recently, photocatalysis combined peroxydisulfate activation under visible light (PC-PDS/Vis) was developed as a promising technology for removing antibiotics in water. Herein, Mn doped FeOOH (Mn-FeOOH) nanoclusters were grown in-situ on the surface of graphitic carbon nitride nanosheets (CNNS) using a wet chemical method, which served as a visible-light-driven photocatalyst for peroxydisulfate (PDS) activation. Photovoltaic property characterizations revealed that Mn-FeOOH/CNNS owned superior light capture ability and carrier separation efficiency. According to DFT calculations, the synergistic effect between Mn and Fe species was proved to enhance the adsorption and activation of PDS. 99.7% of tetracycline (TC) was rapidly removed in 50 min in the PC-PDS/Vis system. In addition, Mn-FeOOH/CNNS exhibited high recycling stability with low iron leaching, attributed to the interaction between Mn-FeOOH clusters and carbon species. Quenching experiments and electron spin resonance (ESR) tests unveiled that •O2- played a significant role in TC removal, while •OH and SO4•- acted as additional roles contributing to the overall process. These findings given a new strategy for antibiotics degradation by photocatalysis, offering deeper insights for the advancement of sustainable and cutting-edge wastewater treatment technologies.


Assuntos
Grafite , Luz , Tetraciclina , Poluentes Químicos da Água , Tetraciclina/química , Poluentes Químicos da Água/química , Grafite/química , Catálise , Antibacterianos/química , Manganês/química , Sulfatos/química , Compostos de Nitrogênio/química , Ferro/química , Processos Fotoquímicos
16.
Environ Res ; 258: 119390, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38879105

RESUMO

Photocatalysis is recognized to be one of the most promising ways to address energy and environmental issues by utilizing visible light. Graphitic carbon nitride (g-C3N4), with a moderate band gap (∼2.7 eV) has been the flashpoint in environmental photocatalysis as it can work better under visible light, can be synthesized by a facile synthesis process using low-cost materials, thermally and chemically stable. Still the photocatalytic performance of g-C3N4 is not satisfactory because of certain limitations such as insufficient visible light absorption capacity, low electron-hole separation efficiency, high recombination rate, poor surface area. Introduction of doping, band structure engineering, defecting and designing of heterojunction, composites etc. were investigated to amplify its applications. Among all these modifications, elemental doping is a suitable and successful alternative for the enhancement of the photocatalytic activity by changing the optical and electronic properties. This review emphasizes on advancement and trends of elemental doping and its application on photocatalytic organic pollutant remediation in aqueous medium. The fundamental photocatalytic activity of heterogeneous photocatalysis and specifically g-C3N4-based photocatalysis have been discussed. The benfits of non-metal doping, enhanced photocatalytic performance by doping element, mechanism invloved in doping, advantages of co-doping has been explained. Mono, bi, and tri non-metal doped g-C3N4 and their application for the removal of organic pollutants from water medium by visible light photocatalysis has been summerized. Life cycle assessment (LCA) of photocatalytic system has been highlighted. Future research should focus on the large-scale application of the photocatalysis process considering the economic aspects. A rigorous life cycle assessment for deploying the non-metal doped g-C3N4-based photocatalysis technology for successful commercial application is recommended.


Assuntos
Grafite , Catálise , Grafite/química , Recuperação e Remediação Ambiental/métodos , Compostos de Nitrogênio/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/análise , Processos Fotoquímicos , Luz , Nitrilas/química
17.
Environ Res ; 256: 119202, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38782343

RESUMO

A rational design of heterojunctions with high-quality contacts is essential for efficiently separating photogenerated charge carries and boosting the solar-driven harvesting capability. Herein, we fabricated a novel heterojunction of SnO2 quantum dots-anchored CdS-CdCO3 with g-C3N4 nanosheets as a superior photocatalyst. SnO2 quantum dots (SQDs) with positively charged surfaces were tightly anchored on the negatively charged surface of CdS nanosheets (NSs). The resulting CdS@SnO2 was finally decorated with g-C3N4 NSs, and a new crystalline phase of CdS-CdCO3 was formed during the hydrothermal decoration process, g-C3N4 decorated CdS-CdCO3@SnO2 (CdS-CdCO3@SnO2@g-C3N4). The as-synthesized photocatalysts were evaluated for the degradation of methyl orange dye under solar light conditions. The CdS-CdCO3@SnO2@g-C3N4 exhibited 7.7-fold and 2.3-fold enhancements in photocatalytic activities in comparison to those of the bare CdS and CdS@SnO2 NSs, respectively. The optimal performance of CdS-CdCO3@SnO2@g-C3N4 is primarily attributed to the cascade-type conduction band alignments between 2D/0D/2D heterojunctions, which can harvest maximum solar light and effectively separate photoexcited charge carriers. This work provides a new inspiration for the rational design of 2D/0D/2D heterojunction photocatalyst for green energy generation and environmental remediation applications.


Assuntos
Compostos de Cádmio , Nanocompostos , Pontos Quânticos , Compostos de Estanho , Pontos Quânticos/química , Compostos de Cádmio/química , Compostos de Estanho/química , Nanocompostos/química , Catálise , Sulfetos/química , Luz Solar , Processos Fotoquímicos , Grafite/química , Compostos Azo/química , Nitrilas/química , Compostos de Nitrogênio/química
18.
Ecotoxicol Environ Saf ; 282: 116701, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39018731

RESUMO

Herein, we reported the dual functions of molybdenum disulfide/sulfur-doped graphitic carbon nitride (MoS2/SGCN) composite as a sensing material for electrochemical detection of 4-NP and a catalyst for 4-NP degradation. The MoS2 nanosheet, sulfur-doped graphitic carbon nitride (SGCN) and MoS2/SGCN were characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) spectroscopy and X-ray photoelectron spectroscopy (XPS). Electrochemical characterization of these materials with electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) in 1 mM K4[Fe(CN)6]3-/4- show that the composite has the lowest charge transfer resistance and the best electrocatalytic activity. The limit of detection (LOD) and the linear range of 4-nitrophenol at MoS2/SGCN modified glassy carbon electrode (MoS2/SGCN/GCE) were computed as 12.8 nM and 0.1 - 2.6 µM, respectively. Also, the percentage recoveries of 4-NP in spiked tap water samples ranged from 97.8 - 99.1 %. The electroanalysis of 4-NP in the presence of notable interferons shows that the proposed electrochemical sensor features outstanding selectivity toward 4-NP. Additionally, the results of the catalytic degradation of 4-NP at MoS2/SGCN show that the nanocatalyst catalyzed the transformation of 4-NP to 4-aminophenol (4-AP) with a first-order rate constant (k) estimated to be 4.2 ×10-2 s-1. The results of this study confirm that the MoS2/SGCN nanocatalyst is a useful implement for electroanalytical monitoring and catalytic degradation of the hazardous 4-NP in water samples.


Assuntos
Dissulfetos , Técnicas Eletroquímicas , Grafite , Limite de Detecção , Molibdênio , Nitrofenóis , Poluentes Químicos da Água , Molibdênio/química , Molibdênio/análise , Nitrofenóis/análise , Nitrofenóis/química , Técnicas Eletroquímicas/métodos , Dissulfetos/química , Catálise , Poluentes Químicos da Água/análise , Grafite/química , Compostos de Nitrogênio/química , Compostos de Nitrogênio/análise , Eletrodos
19.
Mikrochim Acta ; 191(9): 527, 2024 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-39120802

RESUMO

A sophisticated electrochemical sensor is 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 demonstrated exceptional performance with a calculated detection limit (LOD) of 52.0 nM. 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 0.1-83.8 µM SUNI, the anodic peak current exhibited a linear increase with 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.


Assuntos
Técnicas Eletroquímicas , Eletrodos , Grafite , Limite de Detecção , Compostos de Nitrogênio , Sunitinibe , Grafite/química , Humanos , Sunitinibe/química , Sunitinibe/análise , Sunitinibe/sangue , Sunitinibe/urina , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Compostos de Nitrogênio/química , Nanopartículas Metálicas/química , Carbono/química , Óxidos/química , Oxirredução , Nitrilas/química
20.
Mikrochim Acta ; 191(4): 182, 2024 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-38451377

RESUMO

The rapid fabrication is described of binary electrocatalyst based on a highly porous metal-organic framework with zirconium metal core (Zr-MOF) decorated over the graphitic carbon nitride (g-C3N4) nanosheets via facile ultrasonication method. It is used for the robust determination of antipsychotic drug chlorpromazine (CLP) from environmental samples. The electrochemical behaviour of 2D Zr-MOF@g-C3N4 was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies. The crystalline and porous nature of the composite was characterized by XRD and SEM analysis. The functional groups and surface characteristics were investigated by FT-IR, Raman and XPS. The major electrochemical properties of the Zr-MOF@g-C3N4 composite towards CLP detection were analyzed by CV, chronocoulometric (CC), chronoamperometric (CA) and differential pulse voltammetry (DPV) techniques. The composite exhibits a low detection limit (LOD) of 2.45 nM with a linear range of 0.02 to 2.99 µM and attractive sensitivity for CLP. The sensor system shows higher selectivity towards the possible interferences of CLP drug and exhibits better repeatability and stability. Finally, the fabricated sensor system shows a high recovery range varying from 96.2 to 98.9% towards the real samples. The proposed electrochemical probe might be a promising alternative to the prevailing diagnostic tools for the detection of CLP.


Assuntos
Antipsicóticos , Clorpromazina , Espectroscopia de Infravermelho com Transformada de Fourier , Espectroscopia Dielétrica , Eletrodos
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