- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Mineralization of toxic industrial dyes by gallic acid mediated synthesized photocatalyst SnO2 nanoparticles
摘要： This is the first report on gallic acid mediated synthesis of tetragonal rutile tin oxide (SnO2) nanoparticles (NPs) and their photocatalytic activity towards organic dye methylene blue (MB), sunset yellow (SSY) and carmoisine A (CA) under 254 nm UVC irradiations. The crystal structure and crystallite size of SnO2 NPs was confirmed by X-ray diffraction (XRD) studies. The SnO2 NPs mean diameter of 9 nm was obtained by transmission electron microscopy (TEM) analysis. The photoluminescence and absorption studies were carried out by using fluorescence and UV-Vis spectrophotometers. Its band gap was found to be 3.1 eV. The photocatalytic studies have explored the potential of SnO2 NPs towards mineralization of three dyes, which was confirmed by using UV-Vis spectrophotometer and total organic carbon (TOC) analyzer. Our results show that all three dyes were degraded 100% within 50 min under UVC irradiation which suggest its promising capacity in alleviating environmentally pollutant dyes.
关键词： photocatalytic activity,SnO2 NPs,TOC,Gallic acid,photoluminescence
更新于2025-09-10 09:29:36
-
Isothermal crystallization of poly(glycolic acid) studied by terahertz and infrared spectroscopy and SAXS/WAXD simultaneous measurements
摘要： Isothermal crystallization of poly(glycolic acid) (PGA) has been studied using terahertz (THz) and infrared (IR) spectroscopy and simultaneous small-angle X-ray scattering (SAXS)/wide-angle X-ray diffraction (WAXD) measurements. Changes in the intermolecular interactions in PGA during the isothermal crystallization were monitored using THz spectroscopy, which is an efficient technique for analyzing the higher-order structure of polymers. In the THz spectra, the temporal difference in the intensity observed in the isothermal crystallization is due to the difference in the vibrational origins of two bands at 192 and 65 cm?1. The band at 192 cm?1 primarily originates from the intramolecular vibrational mode (twisting of the local structure of the PGA molecular chain). Furthermore, the band at 65 cm?1 exists due to the intermolecular vibration mode (C = O···H-C hydrogen bonds between polymer chains). In addition, these THz bands appeared after the appearance of the SAXS and WAXD peaks. When a lamellar structure is formed and the molecular chains are oriented, the THz band originating from the intermolecular vibration is observed. It is highly possible that the intermolecular vibration appearing in the THz spectra requires the molecular chains to be oriented.
关键词： Terahertz spectroscopy,Intermolecular interactions,Infrared spectroscopy,Isothermal crystallization,SAXS/WAXD,Poly(glycolic acid)
更新于2025-09-10 09:29:36
-
Novel luminescent PLA/MgAl2O4:Sm3+ composite filaments for 3D printing application
摘要： In this work, luminescent bioplastic composite ?laments for 3D printing were fabricated from polylactic acid (PLA) and samarium doped magnesium aluminate phosphor (MgAl2O4:Sm3+). The phosphor was prepared by a metal-complex decomposition method. The obtained powder was then modi?ed by 3-aminopropyl triethoxysilane to improve compatibility with PLA matrix. Untreated and treated phosphors exhibited characteristic photoluminescent (PL) peaks of Sm3+ ion. Composite ?laments of PLA with different amounts of phosphors (0, 1, 2, 3 and 4 phr) were produced by an extrusion process. Differential scanning calorimetry (DSC) scans have revealed that the phosphor ?llers lowered glass-transition (Tg), crystallization (Tc), and melting (Tm) temperatures of the PLA. PL measurements have shown luminescent properties of 3D printed samples resembling those of phosphor powders. Luminescent intensity was increased with the increasing ratio of phosphors. The phosphors not only developed luminescence but also strengthened mechanical properties of the composites. Furthermore, surface modi?cation was able to improve the mechanical properties of the composite ?laments as evident in a series of mechanical tests.
关键词： Polymer composite,3D printing,Samarium doped magnesium aluminate,Polylactic acid,Phosphor
更新于2025-09-10 09:29:36
-
Epoxy-based polymer incorporating 1-Naphthylamine and sebacic acid moieties: A selective fluorescent sensor for ferric ions
摘要： A new epoxy-based polymer sensor 1 incorporating 1-naphthylamine and sebacic acid moieties was synthesised. The sensor shows ON-OFF type fluorescence selectivity for Fe3+ over other coexistent metal ions such as Cu2+ , Zn2+, Co2+, Ni2+, Cd2+ , Hg2+, Mg2+, Sr2+, Pb2+ and Ca2+ ions.
关键词： chemosensor,Fe3+ ion sensing,Epoxy-based polymer,sebacic acid,naphthylamine
更新于2025-09-10 09:29:36
-
Influence of the Nature of the Nitrogen-Containing Base on the Kinetic Stability of Tetra(1,2,5-thiadiazolo)porphyrazine in Dimethyl Sulfoxide
摘要： The state of tetrakis(1,2,5-thiadizole)porphyrazine in the DMSO medium was studied. The proton-transfer complex that formed was found to be quite stable. This complex was shown to decompose in some strong base solutions after some delay. The influence of either the nature of nitrogen-containing base and NH acidity of the porphyrazine macrocycle on the destruction kinetics of proton-transfer tetrakis(1,2,5-thiadizole)-porphyrazine complexes was investigated.
关键词： destruction,DMSO,tetra(1,2,5-thiadiazolo)porphyrazine,proton-transfer complex,kinetics,nitrogen-containing base,acid?base interactions
更新于2025-09-10 09:29:36
-
AIE-active luminogen for highly sensitive and selective detection of picric acid in water samples: Pyridyl as an effective recognition group
摘要： Detection of nitroaromatic explosives especially picric acid (PA) is considerably worth concern on human safety and homeland security. Herein, we developed an effective probe (APPTPEP) for PA detection in aqueous medium by combination of 1,4-dihydropyrrolo[3,2-b]pyrrole with tetraphenylethylene and pyridine units. The incorporation of tetraphenylethylene unit in the backbone endows the APPTPEP a significant aggregation induced emission (AIE) behavior. Pyridyl group was proved as recognition site for PA and their strong interaction was confirmed by 1H NMR titration and supported by theoretical calculation. Owing to this strong affinity, APPTPEP exhibited high selectivity and sensitivity (limit of detection 31.5 nM) to PA over other nitroaromatic compounds. This research provides new insights into the rational design of AIE-active materials for effective sensing application.
关键词： 1,4-dihydropyrrolo[3,2-b]pyrrole,Picric acid,Aggregation-induced emission,Pyridyl group
更新于2025-09-10 09:29:36
-
Third order nonlinear optical properties of DNA-based biopolymers thin films doped with selected natural chromophores
摘要： The results of linear and nonlinear optical (NLO) studies on thin films of DNA based biopolymers, doped with natural chromophores extracts of sweet paprika, turmeric as well as curry leaves are reported and discussed. The thin films were obtained by spin coating on glass substrates. The spectroscopy measurements show that the extracts absorb in visible, at different wavelengths, revealing an important π electron conjugation. The nonlinear optical measurements, done by the optical third harmonic generation technique at 1064.2 nm fundamental wavelength, show that the fast, electronic origin third order NLO susceptibility of natural extracts, is large and comparable or higher than that measured for synthetic counterparts. The largest one in this study was found for the curry leaves extract: (396.9 ± 40) ×10?14 esu.
关键词： Deoxyribonucleic acid,Nature made chromophores,Third harmonic generation,DNA,DNA-CTMA complex,Cubic nonlinear optical susceptibilities
更新于2025-09-10 09:29:36
-
Study of Bi-directional detection for ascorbic acid and sodium nitrite based on Eu-containing luminescent polyoxometalate
摘要： Eu-containing polyoxometalate K13Eu(SiMoW10O39)2·28H2O (Eu-SiMoW) owns the stimu-chromic and photo-luminescence properties. An ingenious test of ascorbic acid (AA) and sodium nitrite (NaNO2) was carried out based on the dual properties of Eu-SiMoW in solutions. First, the redox reaction of Eu-SiMoW and AA generated the blue reduced Eu-SiMoW, accompanied by fluorescence quenching; then the redox reaction of the reduced Eu-SiMoW and NaNO2 made Eu-SiMoW back to its original pale yellow state with red luminescence. Accordingly, the content of AA and NaNO2 could be measured by the reversible change of color and luminescence of Eu-SiMoW. This bi-directional detection method is first discovered and proven to be a simple and effective method for the detection of AA and NaNO2. The proposed method exhibited a linear response range (LRR) from 0.1 to 0.9 mmol L?1 with a limit of detection (LOD) of 0.53 μmol L?1 in UV–vis spectra and 4.67 μmol L?1 in luminescence spectra for AA as well as a LRR from 0.05 to 0.4 mmol L?1 with a LOD of 1.16 μmol L?1 in UV–vis spectra and 5.39 μmol L?1 in luminescence spectra for NaNO2. Moreover, the fluorescence switching of Eu-SiMoW could be realized by reacting with reductant and oxidant through the redox reaction. The detection mechanism is considered as a fluorescence resonance energy transfer process between discolor component SiMoW and luminescence component Eu in Eu-SiMoW.
关键词： Ascorbic acid,Sodium nitrite,Bi-directional detection,Eu-polyoxometalate,Luminescence switching
更新于2025-09-10 09:29:36
-
Quantitative Determination of Urine Glucose: Combination of Laminar Flow in Microfluidic Chip with SERS Probe Technique
摘要： A surface-enhanced Raman scattering(SERS) sensing approach for urine glucose was developed based on the laminar flow technology in a cross-type microfluidic chip with SERS probes, 4-mercaptophenylboronic acid (MPBA) functionalized Ag nanoparticles. MPBA as the glucose receptor can identify and bind up with glucose at a molar ratio of 2:1, which can cause the aggregation of SERS probes at a certain position of the chip channel and further enhance the SERS signal of MPBA significantly. Thus, the quantitative SERS detection of glucose was achieved indirectly. No sample pretreatment and separation were needed in this method since the SERS detection was achieved in the gradient diffusion and molecular recognition processes between urine glucose and SERS probe in the laminar flow, which simplified the sample treatment procedures, saved detection time and made it feasible for clinic applications. This method shows a good linear relationship within human body’s normal physiological range and has high sensitivity and selectivity. The lowest detection concentration can reach 1.0 mg/dL.
关键词： Urine glucose,4-Mercaptophenylboronic acid,Microfluidic chip,Surface-enhanced Raman scattering(SERS)
更新于2025-09-10 09:29:36
-
Visible Light-Promoted Plasmon Resonance to Induce “Hot” Hole Transfer and Photothermal Conversion for Catalytic Oxidation
摘要： Titanium dioxide (TiO2) semiconductor photocatalysts were photosensitized to the visible spectrum with gold nanospheres (AuNSs) and gold nanorods (AuNRs) to study the ethanol photo-oxidation cycle, with an emphasis towards driving carbon-carbon (C-C) bond cleavage at low temperatures. The photocatalysts exhibited a localized surface plasmon resonance (SPR) that was harnessed to drive the complete photo-oxidation of formic acid (FA) and ethanol (EtOH) via augmented carrier generation/separation and photothermal conversion. Contributions of transverse and longitudinal localized SPR modes were decoupled by irradiating AuNSs-TiO2 and AuNRs-TiO2 with targeted wavelength ranges to probe their effects on plasmonically-assisted photocatalytic oxidation of FA and EtOH. Photocatalytic performance was assessed by monitoring the yield of gaseous products during photo-oxidation experiments using a gas chromatography-mass spectrometry-multiple headspace extraction (GC-MS-MHE) analysis method. The complete oxidation of EtOH to CO2 under visible-light irradiation was confirmed by GC-MS-MHE for both AuNSs and AuNRs on TiO2 at room temperature. Photothermal and local field enhancements were found to aid in selectively cleaving the C-C bond in EtOH to form FA, while FA was further oxidized to CO2 by plasmon-induced electron transfer mechanisms. Under visible light (>420 nm) irradiation, carrier generation/separation and photothermal conversion was achieved, resulting in the photogenerated “hot” holes driving the photo-oxidation primarily on the AuNPs. Specifically, plasmonic enhancement by AuNR-TiO2 enhances EtOH oxidation, providing a method to selectively cleave C-C bonds.
关键词： Carbon-carbon bond cleavage,Photocatalysis,Hybrid Materials,Gold nanoparticles,Ethanol oxidation,Magnetic,Formic acid oxidation,Plasmonics,TiO2,Optical
更新于2025-09-10 09:29:36