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Synthesis of TiO <sub/>2</sub> (B) and High-temperature Stable Anatase TiO <sub/>2</sub> Nanowires by Hydrothermal Method and Investigation of Photocatalytic Activity
摘要： In this study, TiO2 nanowires (TNWs) were synthesized through hydrothermal method and were characterized using X-Ray diffraction (XRD), transmission electron microscopy (TEM) and BET techniques. Monoclinic TiO2 (B) is the dominant phase of TNWs up to 600 ℃ which is completely transformed into a highly crystalline anatase phase at 800 ℃. The photocatalytic activity of TNWs, prepared at various calcination temperatures, was investigated in the removal of Rhodamine B (RhB) as an organic model pollutant. The results indicated that the photocatalytic activity of TNWs, prepared at 800 ℃ calcination temperature (TNWs-800), was better than that of other samples and even TiO2-P25 nanoparticles.
关键词： Anatase TiO2 nanowires,Photocatalytic activity,TiO2 (B),Hydrothermal method,High-temperature
更新于2025-09-10 09:29:36
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Synthesis and magnetic properties of Fe-doped CdS nanorods
摘要： Hexagonal CdS and Fe-doped CdS nanorods were synthesized by a facile hydrothermal method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, UV-vis absorption, photoluminescence and X-ray photoelectron spectroscopy. The magnetic properties of undoped and Fe-doped CdS nanorods were investigated at room temperature. The experimental results demonstrate that the ferromagnetism of the Fe-doped CdS nanorods differ from that of the undoped CdS nanorods. The remanence magnetization (Mr) and the coercive field (Hc) of the Fe-doped CdS nanorods were 4.9×10-3 emu/g and 270.6 Oe, respectively, while photoluminescence properties were not influenced by doping. First-principle calculations show that the ferromagnetism in Fe-doped CdS nanocrystal arose not only from the Fe dopants but also from the Cd vacancies, although the main contribution was due to the Fe dopants.
关键词： hydrothermal synthesis,CdS nanorods,Fe doping,magnetic properties,photoluminescence
更新于2025-09-10 09:29:36
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AIP Conference Proceedings [Author(s) 6TH INTERNATIONAL CONFERENCE ON PRODUCTION, ENERGY AND RELIABILITY 2018: World Engineering Science & Technology Congress (ESTCON) - Kuala Lumpur, Malaysia (13–14 August 2018)] - Hydrothermal synthesis of carbon dots and their luminescence
摘要： The synthesis of carbon dots by hydrothermal method with external heating from precursors such as glucose, citric acid, birch bark soot, cowberry, blueberry, redcurrant, and blackbird cherry are investigated. The photoluminescence studies of these carbon dots at di?erent excitation wavelengths was held. It is shown that there is an e?ect of the shift of luminescence spectra intensity peaks with the increasing of excitation wavelengths. The presence of this e?ect open new perspectives for development of composite materials from carbon dots, starch, and epoxy, which can convert the light of the blue LED into the green.
关键词： composite materials,luminescence spectra,hydrothermal synthesis,carbon dots,photoluminescence
更新于2025-09-10 09:29:36
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The preparation and photocatalytic performance research of CdSe and wool ball-like GO/CdSe microspheres
摘要： Different morphologies of CdSe and GO (graphene oxide)/CdSe microspheres like wool ball and walnut shape have been made through hydrothermal method using CTAB as surfactant. X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), X-ray energy dispersive spectrometer (EDS), scanning electron microscope (SEM), Raman spectra, and UVevis absorption spectrum, were used to intensively investigate the structures, morphologies, chemical compositions and optical properties of CdSe and GO/CdSe microspheres. The results of XRD revealed that GO/CdSe microspheres have lead-zinc mineral structure. The results of XRD, EDS, XPS and Raman spectra showed that GO/CdSe microspheres were grown on GO sheets. Also UVevis absorption spectrum indicated that GO/CdSe microspheres enhanced absorbance in UV light region and visible light region. Through comparative experiments, the results showed that pH ? 4 is the optimal pH value for degrading Rhodamine B (RhB) solution. To study the photocatalytic performance of GO/CdSe microspheres, we catalyzed the degradation of RhB aqueous solution irradiated by visible light. The photocatalytic results showed that the wool ball-like GO/CdSe microspheres exhibited better photocatalytic activity than rough CdSe.
关键词： GO/CdSe microspheres,Hydrothermal method,Morphologies,GO,Photocatalytic activity
更新于2025-09-10 09:29:36
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Synthesis and characterization of Al-Fe-Cu tri-doped TiO <sub/>2</sub> by in-situ hydrothermal for degradation of methylene blue dyes
摘要： Pure TiO2 and a series of Al-Fe-Cu tri-doped TiO2 were synthesized by using in-situ hydrothermal method. The synthesized materials were characterized using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM). The photocatalytic activity of the samples was evaluated for degradation of methylene blue (5mgL-1) in aqueous solution under uv-visible light (λ= <420 nm). The XRD pattern showed that all samples exhibited anatase phase after calcined at temperature 500°C with crystallite size in the range of 10.00-13.23 nm. The FTIR spectra showed three important vibrational modes for vOH, δOH and vTiO that were assigned at range 3411.75-3399.27 cm-1, 1626.91-1630.53 cm-1 and 503.30- 530.93 cm-1, respectively. The degradation rate of Al(1mmol)-Fe-Cu tri-doped TiO2 showed the highest photocatalytic degradation with 93% compared to pure TiO2, Al(2 mmol)-Fe-Cu tri-doped TiO2 and Al(3mmol)-Fe-Cu tri-doped TiO2 were calculated as 76%, 85% and 80%, respectively. Hence, it can be seen that, the amount of Al ion-doping have influence on the photocatalytic degradation.
关键词： Al-Fe-Cu tri-doped TiO2,methylene blue,photocatalytic degradation,in-situ hydrothermal
更新于2025-09-10 09:29:36
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Nanothick aluminate long-afterglow phosphors using inherited hydrothermal deriving
摘要： A novel strategy of the inherited hydrothermal method was used to prepare SrAl2O4: 0.01Eu2+, 0.01Dy3+ (SAO) without boron (ISAO) and boron-doping (BSAO) via NaAlO2 as an aluminum source and mineralizer at 200 °C for 6–24 h. The investigated optical properties was correlated to phase transformation and phosphor morphology. The main constituting phases of Al2(OOH)2 and SrCO3 transformed to monoclinic SrAl4O7 and mixed monoclinic/hexagonal SrAl2O4 then pure monoclinic SrAl2O4 during di?erent hydrothermal period. The hydrothermally prepared samples exhibited ?ower-like morphology. The annealed plate phosphors with nanothick single crystals inherited from hydrothermal feature. The shift of photoluminescence (PL) peak wavelength corresponded to the phase transformation from SrAl4O7 to SrAl2O4 with hydrothermal time for ISAO and BSAO. The PL intensity increased with hydrothermal time due to achieving the pure SrAl2O4 phase with preferred orientation geometry and further enhanced by boron-doping. The afterglow of BSAO was signi?cantly enhanced than ISAO, solid-state prepared MSAO and commercial SAO at the initial 100 s after excitation cut-o?. The boron doped in the BSAO was scarcely on the grain surface as to small grain size. Thus, the afterglow enhancement should be attributed to the boron in the lattice inducing defect traps. Overall, the inherited hydrothermal and boron-doping derived nanothick SAOs with large surface preferred orientation enhanced the PL and afterglow properties.
关键词： Phosphor,Afterglow,Inherited hydrothermal,Aluminate
更新于2025-09-10 09:29:36
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One-step hydrothermal synthesis of carbon dots-polymer composites with solid-state photoluminescence
摘要： Carbon dots (CDs) and CDs-polymer composites were one-step synthesized in a hydrothermal process using hexamethylenetetramine and polycarbonate as precursors. Their optical properties and the application as solid-state phosphors towards white light-emitting diodes (LEDs) were thoroughly investigated. CDs solutions exhibit strong yellow emission under blue illumination and possess excitation-independent luminescent behavior. Owing to precursor polymerization, CDs-polymer composites were synthesized in one step. The dried CDs-polymer composite powders exhibit excellent optical stability and no luminescence quenching was observed. Under light blue illumination, the powders show broad yellow luminescence with the peak wavelength centered at 550 nm and PL quantum yield of 14.86%. For their practical applications, stable white light emission was demonstrated by coating a 455nm blue LED with the powders. Our research offers a valuable reference for growing CDs-polymer composites in a facile, low-cost and low-temperature hydrothermal process and developing white LEDs with light blue LEDs and metal-free phosphors.
关键词： white light-emitting diodes (LEDs),phosphors,solid-state photoluminescence,hydrothermal method,carbon materials,luminescence
更新于2025-09-10 09:29:36
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Two new luminescent ternary Cd(II)-MOFs by regulation of aromatic dicarboxylate ligands used as efficient dual-responsive sensors for toxic metal ions in water
摘要： Two new Cd(II) metal-organic frameworks (MOFs) formulated as [Cd(L)(atpa)]n (1) and [Cd(L)(tbta)(H2O)]n (2) [H2atpa = 2-aminoterephthalic acid, H2tbta = tetrabromoterephthalic acid, L = 1,4-bis(benzimidazol-1-yl)-2-butene] were hydrothermally synthesized. 1-2 were characterized by IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction. 1 displays a 3D framework with five-fold interpenetrating dia topology. 2 holds a 2D corrugated sql layer. Both MOFs were confirmed to be dual-responsive luminescent sensors (Cu2+ and Cr2O7 2- for 1, Hg2+ and Cr2O7 2- for 2) in water through the luminescence quenching experiments. The detection limits for these species were 1.2 μM (Cu2+) and 0.29 μM (Cr2O7 2-) of 1, 0.043 μM (Hg2+) and 0.13 μM (Cr2O7 2-) of 2, respectively. The luminescence quenching mechanism was investigated.
关键词： Hydrothermal synthesis,Luminescence quenching,Semi-rigidity bis(benzimidazole),Crystal structure,Cadmium(II) MOF
更新于2025-09-10 09:29:36
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ZnO nanospheres based simple hydrothermal route for photocatalytic degradation of azo dye
摘要： This novel work presents a promising application to use Zinc oxide nanospheres as nanocatalysts in photocatalytic degradation of methyl orange dye. The hydrothermal route was utilized in the synthesis process of ZnO nanospheres. The size of the synthesized ZnO nanoparticles is around 200-250 nm diameter. The synthesized nano-oxides were characterized utilizing several instruments such as X-ray diffraction, Brunauer, Emmett, and Teller (BET), and scanning electron microscope (SEM). The resulting nanoparticles are utilized as an efficient tool for degradation of methyl orange (MO) dye under UV radiation. Essential parameters were studied on degradation process involving the initial concentration of MO, pH, stirring the solution, dose of the ZnO nanospheres, the oxygen content of the solution, calcination of the nanomaterials. All activity experiments under UV radiation provide excellent results for the degradation process of MO. Also, the recovery of ZnO nanomaterials was investigated based on the photocatalytic process efficiency. The results show the high possibility of reuse ZnO nanospheres for several photocatalytic processes. Also, the nanocatalysts were applied for a real environmental sample with providing high photocatalytic performance.
关键词： methyl orange,ZnO nanospheres,photocatalytic degradation,hydrothermal method,azo dyes
更新于2025-09-10 09:29:36
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Enhanced visible-light-driven photocatalytic activity of F doped reduced graphene oxide - Bi <sub/>2</sub> WO <sub/>6</sub> photocatalyst
摘要： The reduced graphene oxide‐Bi2WO6 (rGO‐BWO) photocatalysts with the different RF/O values (molar ratio of the F molar mass and the O's molar mass of Bi2WO6) had been successfully synthesized via one‐step hydrothermal method. The F‐doped rGO‐BWO samples were characterized by X‐ray diffraction patterns (XRD), field‐emission scanning electron microscopy (FE‐ESEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller surface area (BET), X‐ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectra (DRS). The results indicate that F ions had been successfully doped into rGO‐BWO samples. With the increasing of the RF/O values from 0 to 2%, the evident change of the morphology and the absorption edges of F‐doped rGO‐BWO samples and the photocatalytic activities had been enhanced. Moreover, the photocatalytic activity of F‐doped rGO‐BWO with RF/O = 0.05 were better than rGO‐BWO and the other F‐doped rGO‐BWO under 500 W Xe lamp light irradiation. The enhanced photocatalytic activity can be attributed to the morphology of the intact microsphere that signify the bigger specific surface area for providing more possible reaction sites for the adsorption–desorption equilibrium of photocatalytic reaction, the introduction of F ions that may cause the enhancement of surface acidity and creation of oxygen vacancies under visible light irradiation, the narrower band gap which means needing less energy for the electron hole pair transition.
关键词： photocatalytic activity,rGO‐Bi2WO6,fluorine doping,hydrothermal method
更新于2025-09-10 09:29:36