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Energy transfer in and fluorescence studies of the Eu-Tb doped BPA-phen system
摘要: To enhance the red emission efficiency of Eu3+ complexes, [Eu/Tbx(BPA)3phen] (BPA = bisphenol A, phen = 1,10-phenanthroline) is designed and synthesized. The complexes are characterized fully and their luminescence properties are evaluated. Co-fluorescence is detected in the Eu/Tbx(BPA)3phen complexes, and the existence of Tb3+ enhances the luminescence intensity of the central Eu3+ because of the intramolecular energy transfer from the 5D4 level of Tb3+ to the 5D0 level of Eu3+. The luminescence intensity of europium ions at 615 nm is the highest for Eu/Tb1(BPA)3phen. To improve the thermal stabilities and mechanical properties of pure complexes, Eu/Tb1(BPA)3phen/PAN (PAN = polyacrylonitrile) is used to fabricate fibres by electrospinning. Compared with Eu/Tb1(BPA)3phen (τ = 1.1087 ms), the fibres have a longer fluorescence lifetime of 1.533 ms. The fibres also retain a high quantum yield of 47.16%. Thus, the flexible luminescent fibres have potential applications in many fields.
关键词: electrospinning,Bisphenol A,energy transfer,luminescence
更新于2025-11-20 15:33:11
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Graphitic Carbon Nitride with Carbon Vacancies for Photocatalytic Degradation of Bisphenol A
摘要: Photocatalysis is intensely employed to remove refractory organic pollutants in water, but suffers from low efficiency due to rapid recombination of photogenerated electrons and holes. Here, carbon vacancies modified g-C3N4 (VC-C3N4) is prepared via a handy two-step calcination method and firstly applied in the photocatalytic removal of bisphenol A (BPA). Compared to pristine g-C3N4, the photocatalytic degradation activity of VC-C3N4 for BPA is largely enhanced, whose kinetic constant (k) of BPA degradation is 1.65 times as that of pristine g-C3N4. The enhanced photocatalytic performance of VC-C3N4 is ascribed to critical role of carbon vacancies: On the one hand, carbon vacancies serve as the reservoir of photogenerated electrons to inhibit the recombination of photogenerated holes and electrons. On the other hand, carbon vacancies as conversion centers transfer trapped photogenerated electrons to absorbed O2 for generation of abundant superoxide radical (?O2-), which takes a dominant effect in the photocatalytic degradation process.
关键词: ?O2- species,bisphenol A,carbon vacancies,g-C3N4,photocatalytic degradation
更新于2025-09-23 15:23:52
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Enhanced degradation of BPA in water by PANI supported Ag/TiO2 nanocomposite under UV and visible light
摘要: PANI supported Ag@TiO2 nanocomposite was synthesized via oxidative polymerization of aniline on Ag@TiO2. The Ag@TiO2 nanocomposite was synthesized by the photo reduction of Ag nanoparticles on hydrothermally synthesized TiO2 nanofibers. Raman analysis revealed that the anatase phase of TiO2 was synthesized showing typical peaks at 195 cm-1, 396 cm-1, 514 cm-1, and 637 cm-1. The incorporation of PANI, a carbonaceous material was confirmed by appearance of D-band and G-band in Ag@TiO2-PANI that were located at 1505 cm-1 and 1603 cm-1 respectively. X-ray diffraction (XRD) analysis confirmed the anatase phase of TiO2 was synthesized. Transmission electron microscopy analysis (TEM) analysis revealed that TiO2 nanofibers were synthesized successfully and Ag nanoparticles of different sizes were deposited on their surface. X-ray Photon Spectroscopy (XPS) survey scan of the Ag@TiO2-PANI-nanocomposite revealed that the nanocomposite was made from C, O, Ag, Ti, and N. DRS and Tauc`s plot estimated the band gap of Ag@TiO2-PANI to be 3.0 eV. A comparative study of the photocatalytic performance of Ag@TiO2-PANI catalyst showed better degradation performance under both conditions than pristine TiO2, and Ag@TiO2 with a degradation of up to 99.7% under visible light irradiation. The degradation experiments showed that the reactive species that were dominant in the degradation of BPA were h+ and .O2-. The nanocomposite was re-used to degrade BPA for up to four cycles without losing much of its photocatalytic ability with a removal of at least 90% in the fourth cycle.
关键词: Bisphenol A,Ag@TiO2-PANI,visible light,X-ray photoelectron spectroscopy,UV
更新于2025-09-23 15:22:29
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Controllable synthesis of rhombohedral α-Fe2O3 efficient for photocatalytic degradation of bisphenol A
摘要: One-step controllable synthesis of rhombohedral α-Fe2O3 photocatalyst has been successfully developed by P123 soft template assisted method. A combination analysis of XRD, BET, SEM and HRTEM has documented that P123 surfactant plays a crucial role in the controllable synthesis of rhombohedral α-Fe2O3 with the exposure of (110) and (012). The as-obtained α-Fe2O3 material is efficient for the photocatalytic degradation of Bisphenol A (BPA). About 91% of BPA (30 mg/L) was degraded by using 1 g/L α-Fe2O3 within 6 h under the simulated sunlight irradiation, which was almost twice higher than that of commercial Fe2O3. More importantly, reaction intermediates (e.g., 4, 4′-methylenediphenol, phenol and lactic acid) were confirmed by LC–MS/MS analysis, and the rational pathway of BPA degradation was finally proposed.
关键词: Bisphenol A,Photocatalysis,Rhombohedral α-Fe2O3,P123,Pathway
更新于2025-09-23 15:22:29
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Unsubstituted metallophthalocyanine catalysts for the removal of endocrine disrupting compounds using H2O2 as oxidant
摘要: Advanced oxidation processes have become increasingly important to treat non-biodegradable compounds entering environmental waters. In recent decades, water-soluble metallophthalocyanines have been shown to catalyse H2O2-containing oxidation reactions through the production of unique reactive species, nucleophilic metal-peroxo complexes. Few reports in the literature have examined water insoluble metallophthalocyanines (MPc). The oxidative catalytic activity of water insoluble manganese- and iron-phthalocyanine (MnPc, FePc) at pH 7 has been shown through the decolourisation of methylene blue and removal of bisphenol A. These studies expand on this previous study, exploring the catalytic activity of a range of metallophthalocyanines catalysts under both acidic and neutral conditions. FePc, while only active under neutral conditions, was the best performing catalyst. This activity was significantly improved upon by the addition of acetonitrile as a co-solvent, as well as increasing the ratio of H2O2 to catalyst. MnPc was catalytically active at both pH 3 and 7. FePc and MnPc catalysts showed the ability to remove bisphenol A in the presence of dam water. Reaction rates were reduced for bisphenol A removal with FePc as a catalyst but were unchanged in the presence of MnPc. The removal of 17β-estradiol, estrone, and coumestrol was successfully demonstrated, with greater than 96% removal of all tested EDC’s achieved. This is the first reported study showing the removal of the phytoestrogen, coumestrol. Even though considerably lower concentrations of costly catalysts and oxidation reagents were used in our work, the removal extent of EDC’s by the MPc-catalysed oxidation reactions achieved here compares favourably with literature.
关键词: Bisphenol A,Endocrine disrupting compounds,Metallophthalocyanine,Advanced oxidation processes,Coumestrol
更新于2025-09-23 15:22:29
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Signal-on Electrochemiluminescence Aptasensor for Bisphenol A based on Hybridization Chain Reaction and Electrically Heated Electrode
摘要: A simple and sensitive electrochemiluminescence (ECL) aptasensor has been developed for bisphenol A (BPA) detection. The capture DNA (CDNA) was modified on the heated indium-tin-oxide (ITO) working electrode surface firstly and then hybridized with BPA aptamer to form double strand DNA (dsDNA). The presence of target can cause the releasing of aptamer from the electrode surface since the aptamer prefers to switch its configuration to combine with BPA. Subsequently, the free CDNA will induce hybridization chain reaction (HCR) to produce long dsDNA on the electrode surface. Ru(phen)3 2+ can integrate into the grooves of dsDNA to act as an ECL reagent, thus enhanced ECL signal can be detected. The temperature control during the processes of target recognition and HCR were realized through the heated electrode instead of the bulk solution heating. Furthermore, the performance of the ECL aptasensor can be further enhanced at elevated electrode temperature. Under the optimized conditions, the ECL intensity of the system has a linear relationship with the logarithm of BPA concentration in the range of 2.0 pM-50 nM. The limit of detection (LOD) at 55 °C (electrode surface temperature) was calculated to be 1.5 pM, which was approximately 6.5-fold lower than that at 25 °C. The proposed biosensor has been applied to detect the BPA in drink samples with satisfactory results.
关键词: electrochemiluminescence,hybridization chain reaction,heated indium-tin-oxide electrode,aptamer,bisphenol A
更新于2025-09-23 15:22:29
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One-step electrosynthesized molecularly imprinted polymer on laser scribed graphene bisphenol a sensor
摘要: Bisphenol A (BPA) is a toxic chemical used by industries for production of containers for storage of food and beverages leading to possible health risks. In this work, we present a simple, mask-free, low-cost imprinted sensor based on laser scribed graphene (LSG) technology combined to molecularly imprinted polymers (MIPs) for BPA determination. CO2 laser was used in production of LSG electrodes with high resistivity 58 Ω/square on flexible polyimide sheet leading to the high active surface area of the sensor. LSG device was functionalized with imprinted polypyrrole with a known amount of BPA as template molecule to develop the sensor. The bare LSG, LSG-MIP, LSG-NIP sensors were characterized using Raman spectroscopy, SEM, XRD, AFM. The electrochemical measurements were carried out using cyclic voltammetry and differential pulse voltammetry. Experimental conditions were optimized, including the concentration of pyrrole monomer, the number of polymerization cycles, the concentration of BPA as template and the incubation time. We evaluated the sensitivity of the LSG-MIP sensor in the concentration range between 0.05 μM and 20 μM with a limit of detection of 8 nM. The proposed sensor exhibits high selectivity towards BPA compared to its structural analogs and good reusability. The developed sensor was successfully applied for the detection of BPA in tap, mineral water and in plastic samples. The developed sensor was integrated into a PMMA case connected to the potentiostat to achieve complete isolation and a practical measurement system.
关键词: Molecularly imprinted polymers,Water samples,Electropolymerization,Electrochemical devices,Bisphenol A,Laser scribed graphene
更新于2025-09-23 15:21:01
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Preparation of 3D Au NPs-poly-L-glutamate/graphene Nanocomposite Modified Electrode for Sensing of Bisphenol A
摘要: In this work, a simple, sensitive and rapid electrochemical sensor for bisphenol A determination based on a 3D Au NPs-poly-L-glutamate/graphene nanocomposite was proposed and the structures of the nanocomposite were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopic (FTIR) and X-ray diffraction (XRD). The electrochemical behaviors of bisphenol A on the nanocomposite GCE were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In the potential range of 0.0 ~ 1.0 V, an irreversible oxidation peak appeared on the modified electrode in 0.1 mol L-1 phosphate buffer solution (pH = 6.0). Under the optimum conditions, the anode peak current of bisphenol A increased linearly with the its concentration in the ranges from 0.009 μmol L-1 to 0.1 μmol L-1 and 0.1 μmol L-1 to 1.0 μmol L-1with the detection limit down to 3×10 ?10 mol L-1 (S/N = 3) and the corresponding linear regression equations were Ipa( μA)= ? 0.1129 C ( μmol L-1) + 0.5532 (N = 6, R2 = 0.9057) and Ipa( μA) = ? 0.05970 C ( μmol L-1) + 0.02182 (N = 5, R2 = 0.9950) respectively. The proposed method was successfully used for the determination of bisphenol A content in wastewater and milk samples, and the recoveries were in the range from 98.10% to 104.9%.
关键词: L-glutamic acid,bisphenol A,graphene,sensors,electrochemistry
更新于2025-09-23 15:21:01
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Facet-energy inspired metal oxide extended hexapod decorated with graphene quantum dots: Sensitive detection of bisphenol A in live cells
摘要: The development of crystal-facet metal oxide heterostructures has been of great interest owing to their rational design and multi-functioning properties at the nanoscale level. Herein, we report a facile solution-based method for the synthesis of single-crystal Cu2O nanostructures (i.e. Cu2O-CuO) as a core. The graphene quantum dots (GQDs) with varying concentrations are harvested on the surface of Cu2O extended hexapods (EHPs) in ethanol solution at room temperature via self-assembly, where copper acts as a sacrificial model and stabilizer as well. The Cu2O crystals displayed a good sensing activity toward BPA oxidation owing to high energy facets, dangling bonds and great proportion of surface copper atoms. The structural, morphological, chemical and vibrational investigations were attained in detail, presenting high crystallinity of the hybrid nanocomposite and Cu2O-CuO heterojunction positions along with the growth of GQDs on the core of Cu2O-CuO crystal. The electrochemical sensing performance of as-fabricated Cu2O-CuO@GQDs EHPs has been monitored for the determination of bisphenol A (BPA) as an early diagnostic marker and environmental contaminant. The synergy effect of boosted surface area, exposed Cu {111} crystallographic planes and mixed copper valences enhance redox reaction kinetics by increasing the electron shuttling rate at the electrode-analyte junction. Benefitted from the improved electrocatalytic activity for BPA oxidation, the electrochemical sensor displayed the lowest limit of detection (≤1 nM), good chemical stability and broad linear range (2 nM - 11 mM), and high sensitivity (636 μA mM-1 cm-2). The Cu2O-CuO@GQDs EHPs based sensing platform has been applied for BPA detection in water and human serum samples. We have also constructed up a pioneering electrochemical sensing podium for BPA detection in live cells which might be used as a marker in early disease diagnosis.
关键词: electrochemical sensor,bisphenol A,live cells,graphene quantum dots,crystal-facet metal oxide heterostructures
更新于2025-09-23 15:19:57
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Cyano-rich mesoporous carbon nitride nanospheres for visible-light-driven photocatalytic degradation of pollutants
摘要: Visible-light-responsive photocatalysis offers exciting opportunities for sustainable environmental pollution control, but the unsatisfactory photoactivity of the existing photocatalysts impedes their practical application. Here, we fabricated a high-activity mesoporous carbon nitride nanosphere (MCNS) photocatalyst by a hard template synthesis method through incomplete polycondensation of the cyanamide precursors during thermal polymerization. The MCNS showed a unique nanosphere structure with a larger specific surface area and possessed more abundant cyano groups than two other graphitic carbon nitride (g-C3N4) materials (i.e., nanosheet and bulk g-C3N4). Experimental results and theoretical calculations indicate important roles of the cyano groups in narrowing the catalyst band gap to favor visible light absorption and accelerating the separation of the electron–hole pairs. With such superior surface properties and improved charge separation efficiency, the MCNS exhibited 14.7 times higher photocatalytic activity for bisphenol A (BPA) degradation than the bulk g-C3N4. The MCNS also showed good stability during repeated use. Therefore, the as-prepared MCNS has great potential for visible-light-responsive photocatalysis in environmental remediation and other photocatalytic applications.
关键词: pollutant degradation,visible-light-driven photocatalysis,bisphenol A,environmental remediation,Cyano-rich mesoporous carbon nitride nanospheres
更新于2025-09-19 17:15:36