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FACILE HYDROTHERMAL SYNTHESIS OF FLOWER-LIKE ZNONANORODS WITHOUT CATALYSTS
摘要： A very simple hydrothermal method (one step) was used at low temperature to synthesis flower-like ZnOnanorods on glass substrate without any template, catalyst or buffer layer before the reaction. Flower-like ZnOnanorods were synthesized by hydrothermally heating 0.1 M Zn(NO3)2.6H2O, hexamethylenetetramine (HMT) and NaOH were the starting materials for the chemical reaction under stirring. The field emission scanning electron microscopy (FE-SEM) images showed that the flower-like structures were formed in 3.5 h hydrothermally-heated for sample, whereas the experimental pattern of the films by X-ray diffraction show that diffraction peaks can be assigned to the wurtzite hexagonal-shaped ZnO as shown in the (FE-SEM) images, also the morphology of the films studied by atomic force microscope (AFM) shows that the films have high roughness. The energy gap was estimated and optical behavior was investigated.
关键词： hydrothermal process,Flower-like ZnOnanorods,ZnO
更新于2025-09-23 15:22:29
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Photocatalytic degradation and adsorption of phenol by solvent-controlled TiO2 nanosheets assisted with H2O2 and FeCl3: Kinetic, isotherm and thermodynamic analysis
摘要： Hydrofluoric acid (HF) has been widely employed to regulate the surface characteristics of TiO2 containing sheet-like morphology with (001) facets for various environmental applications. However, carcinogenic effects associated with HF are the main stumbling blocks on its way towards global commercialization. In the same line of action, an eco-friendly approach for the synthesis of anatase TiO2 nanosheets (TNSs) via employing hydrothermal process and N, N dimethylformamide (DMF) as a novel morphology-controlling agent has been reported. The as-produced TNSs were characterized by XRD, HRTEM, Raman, FTIR, XPS and DRS characterizations. The photoactivity of as-produced TNSs was studied for photocatalytic degradation of phenol under visible light irradiation in the presence of green oxidants such as hydrogen peroxide (H2O2) and ferric chloride (FeCl3) to produce free hydroxyl radicals for speedily reduction of recombination of photogenerated electrons hole-pairs. The results revealed that as-produced TNSs could activate by green oxidants with yielding upto 94.19 and 97.12 % phenol degradation in the presence of H2O2 and FeCl3, respectively. Moreover, phenol adsorption data was well explained via pseudo first order and pseudo second order kinetics while Langmuir and Freundlich isotherms were more suitable to explain the adsorption of phenol onto TNSs, providing maximum adsorption capacity up to 23.596 mg/g. Various thermodynamic parameters were evaluated, suggesting the favourable, spontaneous and endothermic adsorption process. The values of activation energy (18.505 kJ/mol) confirmed the physical adsorption of phenol onto TNSs. The excellent aptitude of anatase TNSs to produce hydroxyl radicals and super-oxides radicals with promptly lessening of recombination of photogenerated electron hole-pairs makes them motivated applicant for wastewater treatment.
关键词： N, N dimethylformamide,green oxidants,adsorption mechanism,Hydrothermal process,TiO2 nanosheets,phenol
更新于2025-09-23 15:21:01
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A Novel Nanorod Self-Assembled WO <sub/>3</sub> ?· H <sub/>2</sub> O Spherical Structure: Preparation and Flexible Gas Sensor
摘要： In this work, a novel WO3·H2O spherical structure which was self-assembled by nanorods was achieved by using hydrothermal method. A comprehensive growth mechanism was proposed to explain the formation of three different type nanostructures. Flexible gas sensors were successfully fabricated based on such unique nanostructures. We found that these nanorods and nanoparticle’s self-assembled spherical structure showed excellent gas response to ammonia. This result may provide great benefit potential to further study for the preparation and gas performance of such self-assembled structure of WO3·H2O.
关键词： WO3·H2O,Nanostructures,Self-Assembly,Hydrothermal Process,Gas-Sensing
更新于2025-09-23 15:21:01
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The fabrication of a biomass carbon quantum dot-Bi <sub/>2</sub> WO <sub/>6</sub> hybrid photocatalyst with high performance for antibiotic degradation
摘要： A novel biomass carbon quantum dots@Bi2WO6 (BC-QDs@Bi2WO6) photocatalyst with uniform dispersivity was prepared via a dialysis-assisted hydrothermal process. Multiple techniques including HR-TEM, XPS, UV-Vis, PL, photocurrent analysis, and electrochemical impedance spectroscopy were employed to investigate the morphology and structures as well as the optical and electronic properties of the as-prepared samples. The photocatalytic activity of BC-QDs@Bi2WO6 was assessed by the degradation of antibiotics (tetracycline, ciprofloxacin, and gatifloxacin). The improved photocatalytic activity was attributed to the quantum effect of BC-QDs, which acted as the light harvesting center, electron reservoir, and reaction center for degrading the pollutants. Furthermore, a plausible mechanism for photocatalysis was put forward according to the ESR and quenching experiments. The present work can have significant advantages in the construction of biomass carbon-based photocatalysts in pollutant degradation and improved light utilization.
关键词： Bi2WO6,dialysis-assisted hydrothermal process,photocatalyst,biomass carbon quantum dots,antibiotic degradation
更新于2025-09-16 10:30:52
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Efficient UV photodetectors based on Ni-doped ZnS nanoparticles prepared by facial chemical reduction method
摘要： Ni-doped ZnS nanoparticles are synthesized by simple hydrothermal process for the utilization in UV photodetectors. Surface morphology of the prepared samples is investigated through high resolution transmission electron microscopy (HRTEM), which reveals that the prepared nanoparticles are smaller than 20 nm. The well visualized selected area electron diffraction rings suggests the nanocrystalline nature of the prepared nanoparticles with (hkl) planes (111), (220) and (311). The structural analysis is done by x-ray diffraction (XRD) studies; which reveal the decrease in crystallite size with increase in Ni-doping concentration. The device performance of the photodetectors is tested under UV-A light (wavelength ?365 nm) and found that the ability of the prepared devices increases with increase in Ni-doping concentration. This can be attributed to the enhanced surface to volume ratio and increase in charge carrier concentration. The adsorption-desorption of oxygen molecules on the nanoparticles’ surface is considered to be the mechanism for UV photodetection.
关键词： Hydrothermal process,UV-Photodetectors,ZnS nanoparticles
更新于2025-09-16 10:30:52
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Hierarchical flower-like TiO2 microspheres with improved dye-sensitized solar cell performance
摘要： Hierarchical flower-like TiO2 microspheres (FMS) and TiO2 nanorice (NR) were obtained, respectively, by controlling the dosage of Ti precursor via a simple hydrothermal process. Flower-like TiO2 microspheres consist of nanopetals grown from the center radially, the nanopetals are about several nm in average thickness, and each nanopetal has a thinned tip with an average size of 15 nm. The unique hierarchical TiO2 microspheres with large surface area (118.6 m2 g?1) suggested its potential application in dye-sensitized solar cells (DSSCs). The power conversion efficiency of FMS-based DSSCs (9.58%) is much higher than that of NR-based DSSCs (7.13%), which could be ascribed to its excellent light-scattering and dye absorption ability, shorter electron transport pathway and longer electron recombination time derived from the thin thickness and large specific surface area of nanopetals.
关键词： Dye absorption,Hierarchical flower-like TiO2 microspheres,Hydrothermal process,Light-scattering,Dye-sensitized solar cells
更新于2025-09-12 10:27:22
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Effects of precursor concentration on hydrothermally grown ZnO nanorods as electron transporting layer in perovskite solar cells
摘要： Electron transporting later (ETL) with nanorod structure provides a special passage for which free electrons can easily travel through the layer. ETL also helps to prevent the recombination and to enhance the attaching ability of the perovskite layer and thus improving the conversion efficiency of the perovskite solar cell. In this work, the investigation on the hydrothermal process of n-type ZnO nanorods (ZnO NRs) layer is carried out at the temperature below 100 oC and under the atmospheric pressure. Four concentrations of aqueous precursor solution consisting of zinc nitrate hexahydrate and hexamethylenetetramine are used in the experiment (25 mM, 50 mM, 75 mM and 100 mM). Subsequently, the perovskite solar cells, with normal structure of FTO- glass/ZnO dense layer/ZnO NRs/PCBM/Perovskite/P3HT/Ag, are fabricated. The optimum power conversion efficiency of 2.26% was obtained from the device prepared with 100 mM precursor solution. The concentration of solution used in the hydrothermal process affects the size and density of ZnO NRs and, in turn, affects the conversion efficiency of the cells.
关键词： concentrations,hydrothermal process,normal structure,perovskite solar cells,ZnO nanorods
更新于2025-09-12 10:27:22
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Efficiency Improvement of TiO <sub/>2</sub> Nanorods Electron Transport Layer Based Perovskite Solar Cells by Solvothermal Etching
摘要： The efficiency improvement of perovskite solar cells (PSCs) by solvothermal etching and/or TiCl4 treatment of TiO2 nanorod arrays (NRAs) based electron transport layer (ETL) is reported in this article. The TiO2 NRAs are explore for the ETL because of their better direct carrier transportation over other TiO2 nanostructures. The solvothermal etching of TiO2 NRAs enhances the surface-to-volume ratio of the ETL, which, in turn, enhances the power conversion efficiency (PCE) of the PSCs. All the measurements are performed at room temperature and high humid (with ～65% humidity) conditions to demonstrate the performance of the PSCs under normal environmental conditions. A noteworthy efficiency of 15.16% with an improved fill factor and short circuit current density (JSC) is achieved in the proposed PSCs under this article. The performance of the PSC is shown to improve further by exploring TiCl4 treatment of the solvothermally etched TiO2 NRs as the ETL in the device.
关键词： solar cell,solvothermal etching,TiO2 nanorods,perovskite,Hydrothermal process
更新于2025-09-11 14:15:04
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Decorating (001) Dominant Anatase TiO2 Nanoflakes Array with Uniform WO3 Clusters for Enhanced Photoelectrochemical Water Decontamination
摘要： A facile two-step chemical bath deposition (CBD) method has been developed for the preparation of uniformly crystalline anatase WO3/TiO2 array on FTO substrate. The synthesis starts from the hydrothermal growth of TiO2 array in a homogenous HCl aqueous solution containing stabilized titanium isopropoxide, NH4F and acetylacetone (AcAc). Electron microscopy and the XRD analysis suggest the addition of AcAc chelating agent can facilitate the preferential growth of anatase (001) facets that are interconnected and vertically aligned. While (101) dominant TiO2 bipyramid array may form without AcAc. The subsequent decoration of WO3 clusters on TiO2 array is achieved by post-depositing TiO2 array in (NH4)2WO4 aqueous solution followed with a calcination at 450 oC, the resultant WO3/TiO2 array shows a significantly elevated photocurrent performances owing to the high separation efficiency of charge carriers. The enhanced photoelectrocatalytic properties are explained by the efficient charge carrier separation at the heterojunction between WO3 and TiO2. A faster photoelectrochemical degradation of methylene under simulated sunlight further demonstrates the potential usefulness of WO3/TiO2 arrayed photoelectrocatalyst in solar-driven environmental purification and solar fuel synthesis.
关键词： hydrothermal process,WO3,water treatment,TiO2,semiconductor photoelectrocatalysis
更新于2025-09-10 09:29:36
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Enhanced Photocatalytic Activity of TiO <sub/>2</sub> Nanotubes with Acid Treatments
摘要： In this work, we present the enhanced photocatalytic activity of TiO2 nanotubes (TNTs) by hydrothermal method with acid treatment. Firstly, TNTs were synthesized by using a hydrothermal method from commercial TiO2 powder in a 10 M NaOH solution at 130 (cid:3)C for 22 hours. The synthesized solid product after synthesis was then treated by three different post washing procedures: (i) distilled water, (ii) 2 M HCl + distilled water, and (iii) 2 M HNO3 + distilled water. The morphology, structural, and chemical composition of the washed TNT nanostructures were characterized by using the transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy-dispersive X-ray diffraction (EDX). The photocatalytic activities of TNTs were then evaluated through the photocatalytic degradation of the methylene blue (MB) solution. The results reveal that the post washing procedures affect the uniformity, Na impurity of the achieved TNTs and the reduction of Na impurity content, makes for ef?cient photocatalytic properties.
关键词： Photocatalytic,Titanium Dioxide Nanotubes,Hydrothermal Process,Washing
更新于2025-09-09 09:28:46