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Robot path planning with two-axis positioner for non-ideal sphere-pipe joint welding based on laser scanning
摘要： The conversion and degradation of organic pollutants remain challenges relating to environmental science. Herein, we report the carbonization of organic pollutants (4-nitrophenol, 4-NP) toward metal-free nitrogen-doped graphene quantum dots (N-GQDs) using a one-pot solvothermal route. The resultant N-GQDs demonstrate excellent activity for the catalytic conversion of 4-NP to 4-aminophenol (4-AP) when exposed to near infrared (NIR) light because of their excellent upconverted photoluminescence and photothermal conversion ability. The NIR-enhanced reduction efficiency of 4-NP to 4-AP not only originates from the enhanced collisions between N-GQDs and 4-NP due to photothermal-increased Brownian movement of molecules, but also comes from the accelerated transfer rate of electrons produced by the photoexcitation of N-GQDs under NIR irradiation. The N-GQDs display excellent photostability and remain high activity even after five cycles of reuse. Such conversion of organic pollutants to highly efficient metal-free carbocatalysts has significant importance in relevance of the industrial production of aniline and paracetamol.
关键词： organic pollutants,metal-free photocatalysts,4-nitrophenol reduction,nitrogen-doped graphene quantum dots,NIR-enhanced catalytic activity
更新于2025-09-19 17:13:59
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Synthesis of ZnO and Au@ZnO core/shell nano-catalysts by pulsed laser ablation in different liquid media
摘要： We report the synthesis of colloidal solution of ZnO and Au@ZnO core/shell nanoparticles by one-pot nanosecond laser ablation (1st harmonic of Nd:YAG laser) method in different liquid media (Ultrapure water and Chloroauric acid). The structural, morphological and optical properties had been studied. X-ray diffraction analysis showed their hexagonal wurtzite structure while UV–vis analysis investigated the quantum confinement and surface plasmon resonance of the prepared nanostructured particles with significant changes in color behavior. Transmission electron microscopic analysis revealed the homogeneous spherical shape with an average particle size about 39 nm and 50 nm for Au@ZnO core/shell and ZnO, respectively. Also, it is confirmed that the produced nanostructured material in the case of chloroauric acid is core/shell structure where Au is the core while ZnO is the shell. In contrast to ZnO, Au@ZnO displayed more significant Chemical-catalytic degradation activity toward the degradation of 4-nitrophenol to 4-aminophenol in only 4 min rather than ZnO that required 12 min for the same degree of conversion.
关键词： ZnO,Laser ablation,Nanoparticles,4-nitrophenol,Core/shell
更新于2025-09-19 17:13:59
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Synthesis of graphene quantum dots stabilized CuNPs and their applications in CuAAC reaction and 4-nitrophenol reduction
摘要： Here we report the synthesis of graphene quantum dots (GQDs) stabilized copper nanoparticles in neat water. Construction of six CuNPs 1-6 nanocomposites are accomplished by mixing GQDs and NaBH4, and followed by the addition of different amounts of copper sulfate at 0 ℃ in water, respectively. Among them, CuNP-3, with the size of 2.6 nm, exhibits excellent catalytic performance in the CuAAC reaction over than other CuNPs. Moreover, the CuNP-3 has also been successfully applied for the reduction of 4-nitrophenol with excellent catalytic activity.
关键词： 4-Nitrophenol reduction,Copper nanoparticles,CuAAC reaction,Graphene quantum dots
更新于2025-09-19 17:13:59
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Growth, structural, Hirshfeld surface, optical, laser damage threshold, dielectric and chemical etching analysis of 4-dimethylaminopyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP)?single crystal
摘要： The organic 4-dimethylaminopyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP) single crystal was grown by slow evaporation solution growth technique at 35 °C. The single crystal X-ray diffraction analysis confirms that the grown crystal belongs to the orthorhombic crystal system with the space group of P212121. Different functional groups were affirmed using FT-IR and FT-Raman analysis. The intermolecular interactions of the DMAPNP molecule were executed using Hirshfeld surface study. The Mulliken atomic charge population analysis was performed using density functional theory (DFT). The bonding interactions between two orbital atoms and groups were executed by the density of state (DOS). The optical transmittance study shows that the grown crystal has 60 to 78% transmittance in the Vis–NIR region. It has an emission peak at 482 nm in the photoluminescence (PL) spectrum. The photoconductivity analysis shows that the DMAPNP has negative photoconductive behavior. The thermal stability of the DMAPNP crystal was investigated by TG–DTA analysis. The etch pit density of the title crystal was investigated using chemical etching study. The mechanical stability of the DMAPNP crystal was tested by Vickers microhardness tester. Laser damage threshold analysis reveals that the DMAPNP is stable up to 10 mJ of laser power. The dielectric properties were assessed and the electronic polarizability of the DMAPNP was evaluated by the different empirical relations. The second harmonic generation (SHG) efficiency of DMAPNP crystal was measured by Kurtz–Perry powder technique.
关键词： optical,4-dimethylaminopyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP) single crystal,Growth,chemical etching analysis,dielectric,Hirshfeld surface,structural,laser damage threshold
更新于2025-09-16 10:30:52
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Pulsed laser synthesis of highly active Ag–Rh and Ag–Pt antenna–reactor-type plasmonic catalysts
摘要： Ag, Pt, and Rh monometallic colloids were produced via laser ablation. Separate Ag–Rh and Ag–Pt heterostructures were formed by mixing and resulted in groupings of Rh/Pt nanoparticles adsorbing to the concavities of the larger Ag nanostructures. The 400 nm Ag plasmonic absorption peak was slightly blue-shifted for Ag–Pt and red-shifted for Ag–Rh heterostructures. Catalytic activity for the reduction of 4-nitrophenol increased significantly for Ag–Pt and Ag–Rh compared to the monometallic constituents, and persisted at lower loading ratios and consecutive reduction cycles. The enhancement is attributed to the Rh and Pt nanoparticles forming antenna–reactor-type plasmonic catalysts with the Ag nanostructures.
关键词： Pt,catalysis,multicomponent,Rh,nanoparticles,antenna–reactor,4-nitrophenol,heterostructures,Ag,laser ablation,plasmonic
更新于2025-09-16 10:30:52
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Preparation of hexagonal micro-sized α-Al2O3 platelets from a milled Al(OH)3 precursor with NH4F and NH4Cl additives
摘要： In the present work, an Ni5P4/Ni porous composite with a Ni foam as the skeleton was prepared through phosphorization calcination at 500 1C. Meanwhile, the catalytic activity of the as-prepared Ni5P4/Ni porous composite was explored for the treatment of a large-volume e?uent with a high concentration of 4-nitrophenol at room temperature. At last, the catalytic mechanism was discussed preliminarily. The results indicated that the Ni5P4/Ni porous composite possessed remarkable catalytic activity for the borohydride-assisted reduction of 4-nitrophenol. When the concentration of 4-nitrophenol was 1.0 (cid:2) 10(cid:3)3 mol L(cid:3)1, the catalytic reduction e?ciency of 4-nitrophenol was up to 99% within 13 min over the aforementioned sample. More interestingly, it was suitable for the treatment of a large-volume e?uent with a high concentration of 4-nitrophenol. Almost 99% of 4-nitrophenol (1.0 (cid:2) 10(cid:3)2 mol L(cid:3)1, 100 mL) could be removed within 30 min. Even when 4-nitrophenol was near saturation in water (5.0 (cid:2) 10(cid:3)2 mol L(cid:3)1), 4-nitrophenol could still be removed absolutely from water after a 165 min reaction in the presence of the Ni5P4/Ni porous composite. In the catalytic process, Ni5P4 could serve as the active sites and accelerate the formation of hydrogen atoms from BH4(cid:3). Meanwhile, the Ni skeleton could make the electron transfer faster in the catalytic system. Besides, the macroporous structure of the sample also played an important role in the catalysis process.
关键词： room temperature,large-volume effluent,4-nitrophenol,catalytic reduction,Ni5P4/Ni porous composite
更新于2025-09-11 14:15:04
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Preparation of amine functionalized g-C3N4@H/SMOF NCs with visible light photocatalytic characteristic for 4-nitrophenol degradation from aqueous solution
摘要： At ambience temperature, a facile and large-scale sonochemical synthesis route was used to synthesize graphitic carbon nitride@[Ti4C24H39N3O29] metal-organic framework nanocomposites (g-C3N4-X@YTi-MIL125-NH2 NCs, where X and Y stood for the weight percentages of g?C3N4 and the synthesis method of Ti-MIL125-NH2, respectively) having 2-Amino-1,4-benzenedicarboxylic acid (2-ATA) ligand with amine functional free groups. The obtained NCs were characterized by FT-IR, PXRD, FE-SEM, BET, UV-DRS, PL, EIS, and zeta potential. Moreover, g-C3N4-X@YTi-MIL125-NH2 capability to eliminate 4-nitrophenol (4-NP) contaminant from water via visible light illumination was explored. Our synthesized NCs under a facile, green ultrasonic technique (i.e. g-C3N4-30@STi-MIL125-NH2) had a higher percentage of degradation than those from hydrothermal technique (i.e. g-C3N4-30@HTi-MIL125-NH2) with degradation percentages of 75% and 57%, respectively, which resulted in effective mass transfer and separation of photo?generated charge carriers. Additionally, this higher percentage of degradation could be attributed to the larger surface area and unique morphology of the ultrasonically synthesized particles with higher homogeneity and better and non-agglomerated distribution. Furthermore, excellent reusability and stability were observed for g-C3N4-30@STi-MIL125-NH2. We also explored the role of some scavengers in the degradation procedures to investigate the effect of active species. The experimental results were used to describe the suggested mechanism capability for improved photocatalysis.
关键词： Sonochemistry,Photocatalytic degradation,4-Nitrophenol,Metal-organic Framework,g-C3N4@Ti-MIL125-NH2 NCs
更新于2025-09-10 09:29:36
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Novel insights into the properties of AgBiO3 photocatalyst and its application in immobilized state for 4-Nitrophenol degradation and bacteria inactivation
摘要： This study focuses on the synthesis of novel AgBiO3 nanoparticles by the hydrothermal route and investigating its properties responsible for waste water treatment. The temperature and time of hydrothermal reaction was optimized to 150°C and 24 h to obtain highly active crystalline nanoparticles, as determined by XRD. The oxidation state of each element in the material was determined from XPS analysis. The morphology and size of the nanoparticles was obtained from SEM and TEM analysis. The optical and electrochemical properties of the material were studied by UPS and Mott Schottky plot. AgBiO3 was found to have a low band gap that facilitates the absorption of higher wavelength range as confirmed by Tauc plots and UV-Vis DRS analysis. The excellent photocatalytic activity of the immobilized material towards the degradation of 4-nitrophenol and inactivation of E. coli was confirmed from kinetic studies and stability tests. A maximum degradation of 90% was achieved for 4-NP and a 5-log reduction was observed for viable E. coli cells in 5 h and 1 h respectively. Scavenger studies were performed to identify that superoxide radicals were responsible for the photocatalytic activity of the material. To eliminate the cost of separation and ease the reusability of the material, the nanoparticles were immobilized on cellulose acetate. Leaching of Ag and Bi ions from immobilized as well as free AgBiO3 nanoparticles into water was obtained via ICP-MS analysis. The results indicated that the leaching of Ag and Bi was controlled to a considerable extent due to immobilization on cellulose acetate matrix.
关键词： bacteria inactivation,nanoparticle synthesis,nitrophenol degradation,immobilization
更新于2025-09-10 09:29:36
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The carbon dots as colorimetric and fluorescent dual-readout probe for 2-nitrophenol and 4-nitrophenol detection
摘要： Herein, the fluorescent carbon dots (CDs) has been synthesized by hydrothermal method by using ethylene diamine tetraacetic acid (EDTA) as a raw materials. The prepared CDs exhibited bright blue fluorscence excited by 340 nm with the quantum yield as high as 52%. The CDs possess special fluorescence responses to 2-nitrophenol (2-NP) and 4-nitrophenol (4-NP), and the slump of fluorescence was demonstrated by CDs solution in the case of 2-nitrophenol and 4-nitrophenol existence. The detection limit of 2-NP and 4-NP was calculated at 77 nM and 60 nM, respectively. Meanwhile, the color response to 2-NP and 4-NP can be observed from achromatic solution to yellow by naked eye. All in all, the obtained CDs can be applied as fluorescence and colorimetric probe in environmental protection.
关键词： Carbon dots,Dual-readout probe,2-nitrophenol,4-nitrophenol,Detection
更新于2025-09-09 09:28:46
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Quantum confinement chemistry of CdS QDs plus hot electron of Au over TiO2 nanowire protruding to be encouraging photocatalyst towards nitrophenol conversion and ciprofloxacin degradation
摘要： Solar light harvesting science is ascertained to be the topmost effective green technique in alleviating environmental pollutants. In this respect, we report a visible light active TiO2/Au/CdS QDs nanocomposite which manifested upgraded photocatalytic activity towards the transformation of 2-nitrophenol, 4-nitrophenol, and degradation of ciprofloxacin. Here, TiO2 nanowire is synthesized by a molten flux method with high product yield and crystallinity with organized dimensions. Au nanoparticles are successfully integrated in between TiO2-CdS composite by Reverse Turkevich method. The prepared composites are meticulously characterized by different physical and optoelectronic techniques to inspect the crystal structure, phase purity, optical properties, nanostructured morphology and electrochemical properties. The plasmonic direct hot electron transfer (DET) mechanism is confirmed from UV-Vis DRS spectra. The prepared composite produces 2.98 mA/cm2 of current density under light irradiation. A Longer lifetime of electrons is found from Bode phase plot i.e. 97.4 μs for TiO2/1%Au/3%CdS QDs owing to the integrative cooperation effect of high aspect ratio of TiO2 nanowire, quantum size effect of CdS and the direct hot electron transfer by Au nanoparticle.
关键词： TiO2 nanowire,2-nitrophenol,DET,4-nitrophenol,ciprofloxacin,CdS QDs
更新于2025-09-09 09:28:46