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Aminoboronic acid-functionalized graphitic carbon nitride quantum dots for the photoluminescence multi-chemical sensing probe
摘要： This paper reports a highly sensitive photoluminescence glucose sensor based on aminoboronic acid-functionalized carbon nitride quantum dots (g-CNQDs/3APBA) fabricated using melamine and 3-aminophenylboronic acid via a facile two-step synthesis process. By introducing the covalent bonds between g-CNQDs and boronic acid groups, it can be effectively used as “on-off-on” based multi-chemical sensor. The g-CNQDs/3APBA exhibited quantum yields (QYs) as high as 78.5%, which is the highest QYs among fluorescence sensors based on g-CNQDs reported thus far. The material showed a wide linear range of 0 – 10 mM and a detection limit as low as 42 nM with excellent selectivity. In addition, it exhibited comparable performance compared to those of a commercial glucometer in a real blood test. Owing to the excellent bio-imaging properties and low cytotoxicity, g-CNQDs/3APBA is a promising candidate as a sensing material for biomedical and clinical applications.
关键词： quantum dots,glucose sensor,multi-chemical sensor,fluorescence,Graphitic carbon nitride,3-aminophenylboronic acid
更新于2025-11-20 15:33:11
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Laser-induced synthesis and photocatalytic properties of hybrid organic–inorganic composite layers
摘要： A laser-based method was developed for the synthesis and simultaneous deposition of multicomponent hybrid thin layers consisting of nanoentities, graphene oxide (GO) platelets, transition metal oxide nanoparticles, urea, and graphitic carbon nitride (g-C3N4) for environmental applications. The photocatalytic properties of the layers were tested through the degradation of methyl orange organic dye probing molecule. It was further demonstrated that the synthesized hybrid compounds are suitable for the photodegradation of chloramphenicol, a widely used broad-spectrum antibiotic, active against Gram-positive and Gram-negative bacteria. However, released in aquatic media represents a serious environmental hazard, especially owing to the formation of antibiotic-resistant bacteria. The obtained results revealed that organic, urea molecules can become an alternative to noble metals co-catalysts, promoting the separation and transfer of photoinduced charge carriers in catalytic composite systems. Laser radiation induces the reduction of GO platelets and the formation of graphene-like material. During the same synthesis process, g-C3N4 was produced, by laser pyrolysis of urea molecules, without any additional heat treatment. The layers exhibit high photocatalytic activity, being a promising material for photodegradation of organic pollutants in wastewater.
关键词： transition metal oxide nanoparticles,urea,photocatalytic properties,hybrid organic–inorganic composite layers,graphene oxide,graphitic carbon nitride,methyl orange,laser-based synthesis,chloramphenicol
更新于2025-11-14 17:04:02
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Electrochemiluminescence sensing platform for ultrasensitive DNA analysis based on resonance energy transfer between graphitic carbon nitride quantum dots and gold nanoparticles
摘要： Electrogenerated chemiluminescence (ECL) of semiconductor quantum dots (QDs) is considered as a powerful technique in the fabrication of biosensor, however, the inherent toxicity of the heavy metal ion containing in QDs limits their further applications. Thus, searching for environment-friendly luminescent nanomaterials with high electrochemiluminescence (ECL) e?ciency is an urgent goal. In this work, a solid-state method under low temperature was adopted to prepare graphitic carbon nitride quantum dots (g-CNQDs). By using coreactant K2S2O8, a strong cathodic ECL signal of g-CNQDs could be observed in phosphate bu?er. A novel ECL resonance energy transfer procedure was constructed between g-CNQDs (emitter) and gold nanoparticles (acceptor). A signal probe was formed by connecting gold nanoparticles at the hairpin DNA (Hai-DNA) terminal. When the signal probe was anchored on g-CNQDs, ECL resonance energy transfer occurred due to the ECL quenching of gold nanoparticles to g-CNQDs. This phenomenon decreased the ECL signal. In the presence of target DNA (T-DNA), the looped structure of Hai-DNA could be destroyed by T-DNA, and gold nanoparticles were separated from g-CNQDs. Accordingly, the ECL resonance energy transfer procedure was hindered, and the ECL signal was recovered again. The ECL intensities exhibited linear correlation with the logarithm of T-DNA concentration from 0.02 fM to 0.1 pM, and the limit of detection was 0.01 fM (3σ). With the developed ECL resonance energy transfer system, good selectivity and high sensitivity were achieved in T-DNA detection.
关键词： Graphitic carbon nitride quantum dots,Electrochemiluminescence,DNA,Resonance energy transfer,Biosensor
更新于2025-11-14 17:04:02
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In-Situ Synthesis of Nb2O5/g-C3N4 Heterostructures as Highly Efficient Photocatalysts for Molecular H2 Evolution under Solar Illumination
摘要： This work focuses on the synthesis of heterostructures with compatible band positions and a favourable surface area for the efficient photocatalytic production of molecular hydrogen (H2). In particular, 3‐dimensional Nb2O5/g‐C3N4 heterostructures with suitable band positions and high surface area have been synthesized employing a hydrothermal method. The combination of a Nb2O5 with a low charge carrier recombination rate and a g‐C3N4 exhibiting high visible light absorption resulted in remarkable photocatalytic activity under simulated solar irradiation in the presence of various hole scavengers (triethanolamine (TEOA) and methanol). The following aspects of the novel material have been studied systematically: the influence of different molar ratios of Nb2O5 to g‐C3N4 on the heterostructure properties, the role of the employed hole scavengers, and the impact of the co‐catalyst and the charge carrier densities affecting the band alignment. The separation/transfer efficiency of the photogenerated electron‐hole pairs is found to increase significantly as compared to that of pure Nb2O5 and g‐C3N4, respectively, with the highest molecular H2 production of 110 mmol/g·h being obtained for 10 wt % of g‐C3N4 over Nb2O5 as compared with that of g‐C3N4 (33.46 mmol/g·h) and Nb2O5 (41.20 mmol/g·h). This enhanced photocatalytic activity is attributed to a sufficient interfacial interaction thus favouring the fast photogeneration of electron‐hole pairs at the Nb2O5/g‐C3N4 interface through a direct Z‐scheme.
关键词： Z‐Scheme,H2 evolution,hydrothermal synthesis,graphitic carbon nitride,photocatalysis,heterostructures,Niobium(V) oxide
更新于2025-11-14 17:03:37
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Acetylene black quantum dots as a bridge for few-layer g-C3N4/MoS2 nanosheet architecture: 0D–2D heterojunction as an efficient visible-light-driven photocatalyst
摘要： Great progress has been made based on photocatalytic theory research in the past few years. There is, however, still a long way to go to popularize the application of photocatalytic materials. Here, we introduce a simple synthetic 0D–2D (D: dimensional) heterogeneous material with more efficient photocatalytic degradation. We construct acetylene black (AB) as a bridge to connect a graphitic carbon nitride (g-C3N4) nano-layer and two-dimensional MoS2 sandwich structure based on a simple hydrothermal synthesis and ultrasonic chemical loading. Loading 1% AB onto 2D g-C3N4/(x%)MoS2 not only accelerates the transfer of charge, but also reduces electron–hole recombination, which increases the photocatalytic efficiency per unit time. Studies have shown that the degradation rate of the ternary g-C3N4/AB/3.1%MoS2 catalytic materials can reach 94.29%, which is obviously higher than that of the pure g-C3N4 (80%) or MoS2 (51.74%) in degradation of methyl blue within 130 min. In this work, the ternary heterogeneous catalyst realizes the complementary characteristics between materials, broadens the photocatalytic properties and accelerates the degradation rate of pollutants, and provides a feasible solution to environmental friendliness.
关键词： Graphitic carbon nitride,Ternary photocatalyst,Photocatalytic degradation,QDs/g-C3N4/MoS2
更新于2025-11-14 15:32:45
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Visible light photocatalytic mineralization of bisphenol A by carbon and oxygen dual-doped graphitic carbon nitride
摘要： A facile thermal polymerization was applied to synthesize carbon and oxygen dual-doped graphitic carbon nitride (MACN) with controllable electronic band structure using malonic acid and urea as precursors. The C and O atoms substituted the sp2 N atom in graphitic carbon nitride (CN). The 1MACN (1 represented that the weight ratio of malonic acid to urea is 1% during the synthesis) with optimal band structure could decompose 15 ppm bisphenol A (BPA) within 150 min, and the mineralization rate reached to 52%. The superior photocatalytic performance of 1MACN was mainly ascribed to electronic band structure together with optical properties. On the one hand, the formation of delocalized big p bonds favored the electrons transfer after the introducing of carbon atoms. On the other hand, a positive charge density existed on the C atoms because of high electronegativity of contiguous O (3.44) that substituted N compared with C (2.55), which could attribute to high activity of MACN catalyst. The study will contribute to the further improvement of visible-light photocatalytic BPA degradation and mineralization.
关键词： BPA mineralization,Carbon-oxygen dual-doping,Visible-light photocatalytic,Graphitic carbon nitride
更新于2025-09-23 15:23:52
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Hybrid composite of CuO with $$\hbox {g}\hbox {-C}_{3}\hbox {N}_{4}$$g-C3N4 as a photoactive catalyst: an efficient approach for the oxidation of alcohols
摘要： An eco-friendly method for the oxidative transformation of alcohols to their corresponding carbonyl compounds by using g-C3N4@CuO as a photoactive heterogeneous catalyst has been developed. The catalyst was characterized by SEM-EDX, TEM, BET surface area measurements, powder XRD, FTIR, photoluminescence and UV-Vis spectroscopy. It was found to be very effective for the conversion of both primary and secondary alcohols into aldehydes and ketones with excellent yields using tert-butyl hydrogen peroxide (TBHP) as oxidant at room temperature in the presence of visible light in aqueous medium. The catalyst can be separated from the reaction mixture by simple centrifugation and reused up to five cycles without significant loss in activity.
关键词： Nanocomposite,alcohol oxidation,copper oxide,photocatalyst,graphitic carbon nitride
更新于2025-09-23 15:23:52
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Insight into the mechanisms for hexavalent chromium reduction and sulfisoxazole degradation catalyzed by graphitic carbon nitride: The Yin and Yang in the photo-assisted processes
摘要： As robust polymeric catalysts, graphitic carbon nitride (g-C3N4) has been known to have great application potential in environmental remediation. However, the mechanisms in the photo-assisted catalytic processes during the reduction or oxidation of pollutants are still difficult to discern and therefore not well studied. In this work, visible-assisted catalytic reduction of hexavalent chromium (Cr(VI)) or oxidation of sulfisoxazole (SIZ) by g-C3N4 with the addition of formic acid (FA) or potassium peroxydisulfate (PS) were systematically investigated. Effects of operation parameters such as g-C3N4 dosage, FA concentration, Cr(VI) concentration, solution pH, PS concentration were studied. The results showed g-C3N4 can be effective and robust catalyst for both the reduction (Yin) and oxidation (Yang) reactions in the environmental remediation. Mechanisms were studied by using electron spin resonance (ESR) spectroscopy. The results revealed the CO2?? is the predominant radical for Cr(VI) reduction in the g-C3N4/FA/Vis system and the SO4?? and ?OH are all the main radicals for the oxidation of SIZ in the g-C3N4/PS/Vis system. The photo-generated carriers by g-C3N4, act as radical initiator, were responsible for the production of the reactive radical species in aqueous solution. This work not only shed a new light on the application of semiconductor polymers for the removal of micropollutants and also will expand the applicability of the polymeric photocatalysts for environmental remediation.
关键词： Micropollutants,Sulfisoxazole,Hexavalent chromium,Mechanisms,Graphitic carbon nitride
更新于2025-09-23 15:23:52
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Detection of divalent copper with improved accuracy by dual suppression of electrochemiluminescent recovery
摘要： This work is to construct an electrochemiluminescent (ECL) sensor with improved accuracy for the detection of Cu2+. The improved accuracy is achieved by utilizing a reaction system to realize Cu2+ dose-dependent dual suppression of ECL recovery from gold nanoparticle-graphitic carbon nitride nanosheet nanohybrid (Au-CNNS) film. The ECL sensor shows sensitive response to Cu2+ in the concentration range of 5 nM to 500 nM with an enlarged slope, and high specificity attributed to the high affinity of CNNS-Cu2+ complex and the high catalytic activity of Cu(NH3)6 2+ to decompose H2O2 in the reaction system. The proposed ECL sensor with improved accuracy may prove valuable in future biomedical applications.
关键词： dual suppression,electrochemiluminescent sensor,copper,graphitic carbon nitride nanosheets
更新于2025-09-23 15:23:52
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Synthesis of g-C3N4/N-doped CeO2 composite for photocatalytic degradation of an herbicide
摘要： In photocatalysis, surface engineered CeO2 could be vital due to oxygen vacancies arise from multiple valency, i.e. Ce3+ and Ce4+. This study reports photocatalytic properties of g-C3N4/CeO2 composite synthesized by a facile method in the presence of l-arginine. Physicochemical properties of g-C3N4/CeO2 material were analyzed through various characterization techniques such as XRD, UV–Vis, physisorption, etc., and correlated with its photocatalytic activity. Observed bandgap of the synthesized composite material was in the visible region, around 2.8 eV which is less than that of typical ceria, but higher than bandgap of exfoliated g-C3N4. On the further side, N doping into CeO2 was confirmed through XPS analysis. It is estimated that synthesis method aided for the N doping, which further played key role in lowering the bandgap of g-C3N4/CeO2 composite. Finally, Photocatalytic activity of g-C3N4/CeO2 composite was analyzed through degradation of an herbicide i.e. diuron, and the study revealed the good performance of the catalyst.
关键词： Graphitic carbon nitride,Photocatalysis,N doping,Herbicide,CeO2
更新于2025-09-23 15:23:52