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Structural, optical and photoluminescence studies of sol-gel synthesized pure and iron doped TiO2 photocatalysts
摘要： Pure and Iron doped TiO2 nanoparticles were synthesized using the sol-gel method. These materials were characterized by X-ray diffractometer (XRD), high-resolution transmission electron microscope (HR-TEM), scanning electron microscope (SEM), Energy dispersive X-ray (EDX), UV-Vis diffuse reflectance spectroscopy (DRS), Fourier-transform infrared (FTIR), Raman and fluorescence spectrometer. XRD analysis revealed that all the samples were a single phase with anatase nanocrystallite structures. The crystallite size of titania reduced from 9.64 nm to 7 nm with Fe doping. The HRTEM images of the TiO2 and 3% Fe doped TiO2 have revealed that all the particles have a spherical shape with an average particle size of 10 nm and 8 nm respectively. The characteristic peak at 482 cm-1 of the Ti–O bond stretching vibrations can be evidently observed from FTIR analysis. The Raman blue shift was found in the Fe doped TiO2 samples. Fe-doped TiO2 nanoparticles showed a significant red-shift in band edge as compared with pure TiO2 nanoparticles. The redshift of band gap was detected in Fe doped TiO2 nanoparticles. The photoluminescence (PL) emission intensity of Fe doped TiO2 nanoparticles decreases with an increase in Fe doping concentration. The photocatalytic efficiencies of the Fe-doped TiO2 nanoparticles have shown a strong photocatalytic activity (PCA) response. At constant irradiation time, the Fe-doped titania nanoparticles display more catalytic activity compared to undoped TiO2. The photodegradation efficiencies typically decline with an increase in the concentration of Fe+3 doping for the decolorization of methylene blue (MB) under visible light irradiation.
关键词： band gap,Raman modes,photocatalytic activity,TiO2 nanoparticles,methylene blue,PL emission
更新于2025-11-21 11:18:25
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Sensitive spectrophotometric determination of trace-level Co2+ in water based on acetate enhanced catalysis of Co2+
摘要： A sensitive spectrophotometric method was developed for the determination of trace-level Co2+ in water based on the acetate enhanced catalytic decolorization of methylene blue (MB) with Co2+ as a catalyst and peroxymonosulfate (PMS) as an oxidizing agent. This indirect spectrophotometric method was easy to operate due to the strong absorption of MB at a maximum absorption wavelength of 664 nm with a molar absorptivity of 5.88 × 104 L mol?1 cm?1. Under the selected reaction conditions of 10.0 mg L?1 MB, 60.0 mg L?1 PMS and 100.0 mg L?1 Ac?, the depletion extent of MB was linearly correlated with the concentration of Co2+ from 0.20 to 7.0 μg L?1 (R2 = 0.986) and then from 7.0 to 50.0 μg L?1 (R2 = 0.991), with a detection limit (3 s/k) of 0.10 μg L?1. It was found that this method possessed excellent anti-interference capability to various coexisting ions including similar transitional metals. The developed method was used to determine the Co2+ concentration in practical samples with satisfactory results.
关键词： Spectrophotometry,Methylene blue,Catalytic decolorization,Acetate,Trace-level Cobalt
更新于2025-11-19 16:56:35
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One-pot synthesis of 3D Cu <sub/>2</sub> S–MoS <sub/>2</sub> nanocomposites by an ionic liquid-assisted strategy with high photocatalytic activity
摘要： Novel 3D Cu2S–MoS2(x : y) nanocomposites with different proportions of Cu2S (x) and MoS2 (y) are synthesized successfully by a one-step hydrothermal method with the assistance of the ionic liquid [BMIM]SCN. The characterization results show that the nanocomposites are self-assembled from nanosheets of Cu2S and MoS2, they display nanoflower morphology and a typical mesoporous structure. The fabrication mechanism of the nanocomposites is investigated using time-dependent experiments, which indicate the key role of the ionic liquid (IL) in the synthesis process. Furthermore, TAA is used as a sulfur source instead of the IL to form a Cu2S–MoS2 nanocomposite, with the aim of further investigating the effects of the IL on the morphology of the composite. Photodegradation of MB under visible light irradiation experiments were used as probe reactions to evaluate the photocatalytic performance of the as-prepared samples. All the nanocomposites show better catalytic activity than Cu2S and MoS2 monomers. Among the different Cu2S–MoS2(x : y) nanocomposites, the Cu2S–MoS2(1 : 1) composite exhibits the most excellent photocatalytic performance and cycling stability.
关键词： Cu2S–MoS2 nanocomposites,hydrothermal synthesis,photocatalytic activity,ionic liquid,methylene blue degradation
更新于2025-11-14 17:04:02
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Photocatalytic Degradation of Methylene Blue over TiO2 Pretreated with Varying Concentrations of NaOH
摘要： In this paper, different NaOH concentrations (2, 5, 10, and 15 M) were used to treat {001}TiO2. The effect of NaOH on the crystal structure, morphology, optical properties, light raw electronic-hole recombination, and degradation performance of {001}TiO2 on methylene blue were studied. The results demonstrate that rutile TiO2 appeared when the NaOH concentration was as high as 10 M, showing much better photolytic performance than others. As the concentration of sodium hydroxide increases, the morphology changes accordingly. The specific surface area increases and the optical electronic-hole recombination rate decreases. Radical scavenging tests showed that hydroxyl radical and hole are very important in photocatalysis.
关键词： NaOH concentration,radical scavenging,{001}TiO2,methylene blue,photocatalysis
更新于2025-11-14 17:03:37
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AIP Conference Proceedings [Author(s) 2ND INTERNATIONAL CONFERENCE ON CHEMISTRY, CHEMICAL PROCESS AND ENGINEERING (IC3PE) - Yogyakarta, Indonesia (14 August 2018)] - Enhanced photocatalytic activity of WO3 nanoparticles loaded with carbon
摘要： Enhanced photocatalytic activity of WO3 was attempted by carbon nanodots (C-dots) loading. C-dots were prepared using citric acid and urea for enhancing photocatalytic activity of WO3. Physicochemical character of C-dots was studied by fluorescence spectrophotometry and for the modified WO3, evaluation was studied by using x-ray diffraction (XRD) and scanning electron microscope (SEM). Effect of varied citric acid: urea ratio to photocatalytic activity was evaluated in methylene blue photodegradation. Increasing photocatalytic activity was achived by higher intensity in blue color range that obtained by higher urea molar ratio. Kinetics of reaction obey pseudo-first order and pseudo-second order reaction. Reaction reached 80% MB degradation for an hour treatment for 50mM of methylene blue solution.
关键词： photocatalytic activity,methylene blue photodegradation,WO3 nanoparticles,carbon nanodots
更新于2025-11-14 15:15:56
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Photocatalytic Degradation of Methylene Blue and Phenol Using TiO2/Activated-Carbon Composite Catalysts
摘要： Photocatalytic degradation of methylene blue and phenol were conducted separately in aqueous solutions using titania-activated carbon composites. Activated carbon composites of different textural features and light of different wavelength or energy were used in order explore their effects on the performance of titania-activated carbon catalysts. The catalysts (TiAC1, TiAC2 and TiAC3) were prepared by impregnating activated carbon supports with an aqueous suspension of titanium precursor (TiO2). The catalysts were characterized using BET, XRD and FTIR. The diffraction pattern showed strong peaks that are assigned to titanium anatase phase and weaker peaks that indicated low rutile phase. The FTIR showed broad peaks of Ti-O-Ti linkages in TiO2 particles. The photocatalytic degradation of methylene blue and phenol was performed separately in visible light and UV irradiation of different wavelengths. Adsorption was dominant in the case of methylene blue removal while photodecomposition was more pronounced in the case of phenol removal.
关键词： Photocatalysis,Phenol,Methylene blue,Titania,Activated carbon,Precursors
更新于2025-09-23 15:23:52
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Valorization of mutant Bacillus licheniformis M09 supernatant for green synthesis of silver nanoparticles: photocatalytic dye degradation, antibacterial activity, and cytotoxicity
摘要： The present study reports the optimization of a green method for the synthesis of silver nanoparticles (AgNPs) via reduction of Ag+ ions using cell-free supernatant of mutant Bacillus licheniformis M09. UV–Visible spectroscopy showing an absorption peak at ~ 430 nm confirmed the synthesis of AgNPs. Transmission electron microscope (TEM) analysis exhibited spherical AgNPs within the size range of 10–30 nm. Fourier transform infrared (FTIR) measurements assured the presence of effective functional molecules which could be responsible for stabilizing the AgNPs. X-ray diffraction (XRD) pattern verified the crystalline nature of AgNPs. Furthermore, the synthesized AgNPs showed an excellent photocatalytic degradation of methylene blue dye in less than 3 h under visible light proving their potential as a catalytic agent for bioremediation for next-generation dye degradation in effluent treatment. The AgNPs demonstrated antimicrobial activity against Gram-positive and Gram-negative foodborne pathogens which endorsed its suitability as agents to extend shelf-life in food packaging and food safety applications. The results also revealed a strong concentration-dependent cytotoxicity of AgNPs against human breast adenocarcinoma cells (MCF-7), while 15.07 μg/mL of IC50 was attained. The outcome suggests the possible application of these AgNPs in nanomedicine formulations. Thus, these findings propose promising ways for the valorization of the waste fermentation supernatant left after cell harvesting and desired metabolite extraction.
关键词： Methylene blue,Antibacterial,Photocatalytic dye degradation,Cytotoxicity effects,Bacillus licheniformis M09,Silver nanoparticles
更新于2025-09-23 15:23:52
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Graphene oxide-based zirconium oxide nanocomposite for enhanced visible light-driven photocatalytic activity
摘要： In the present investigation, an efficient visible light-active, graphene oxide-based zirconium oxide nanocomposite (GO–ZrO2) has been synthesized by co-precipitation method. The synthesized photocatalyst was characterized by XRD, FTIR, FE-SEM, EDS, TEM, TGA, PL, UV-DRS and BET surface area analysis. The characterization results illustrate the homogeneous dispersion of ZrO2 nanoparticles in the GO–ZrO2 nanocomposite with excellent harmony between GO and ZrO2 nanoparticles. The photocatalytic efficiency of the synthesized GO–ZrO2 nanocomposite was evaluated by photodegradation of hazardous, water-soluble rhodamine B and methylene blue dyes under visible light irradiation. The 90% photocatalytic degradation of rhodamine B dye (with initial conc. 30 mg/L) was observed in 105 min of visible light irradiation, while 99.23% of methylene blue (with initial conc. 100 mg/L) dyes degradation was observed in just 60 min using 25 mg/100 ml dose of GO–ZrO2 nanocomposite as a photocatalyst. The mechanistic investigation using scavengers suggest that the superoxide (O2·?) is the most reactive species involved in the photodegradation of organic dyes. The synthesized photocatalyst GO–ZrO2 nanocomposite also exhibits excellent thermal stability and reusability.
关键词： Methylene blue,Rhodamine B,Photocatalytic activity,Zirconium oxide,Graphene oxide,Visible light,Co-precipitation method
更新于2025-09-23 15:23:52
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Low-cost effective photocatalytic activity under visible light of pitch-based porous carbon nanofiber composites aided by zinc oxide
摘要： To explore and develop an economical, novel, and effective photocatalyst for the degradation of methylene blue (MB) under visible-light irradiation, polyacrylonitrile (PAN)/pitch-based carbon nanofibers (CNFs) with ZnO (PPZn) are successfully produced by one-step electrospinning of PAN, pitch, and zinc acetate in dimethylformamide (DMF) solution. The charge separation rate, adsorption capacity, and visible-light harvesting effects are all enhanced by the synergistic effect of PAN/pitch-based CNFs and ZnO coupling. The resulting PPZn photocatalysts exhibit excellent removal capacity of 100% of MB within 30 min and a kinetic rate constant of 0.018 min?1 under visible light. PPZn also exhibits a consistent and stable photocatalytic performance by maintaining nearly 100% removal of 15 ppm MB over 8 regeneration cycles. The PP-based CNFs in PPZn act as a charge reservoir to afford fast transport for suppressing the e?–h? recombination and high electrical conductivity induced by the pitch, thereby expanding the visible-light response. The PP(3)Zn composites demonstrate a promising potential as a low-cost photocatalyst material offering excellent photocatalytic efficiency in the visible-light spectrum.
关键词： Carbon nanofiber,ZnO,Methylene blue,Pitch,Visible light,Photocatalytic activity
更新于2025-09-23 15:23:52
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ZnO rod decorated with Ag nanoparticles for enhanced photocatalytic degradation of methylene blue
摘要： Silver-zinc oxide nanocomposite (Ag-ZnO nanocomposite) were synthesised with different concentrations of Ag doped to the ZnO for enhance photocatalytic degradation of methylene blue. The structures, morphologies, and optical properties of synthesised nanocomposites were characterized by UV-Visible spectroscopy (UV-vis) scanning electron microscopy (SEM), X-ray diffraction (XRD), Dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FRIR), and photoluminescence spectroscopy (PL). The average size of the synthesized Ag nanoparticles was around 40 nm and ZnO nanorod were 2 μm in length and 200 nm in width. The morphological characterization revealed that Ag nanoparticles were well doped with the ZnO rod surface. The performance and stability of the nanocomposites for the photocatalytic degradation of methylene blue under ultraviolet (UV) light irradiation were evaluated. The overall results suggested that, 6% of Ag nanoparticles achieved better degradation than compare to the other concentrations and bare ZnO. This work provides a simple and effective route to prepare Ag-ZnO nanocomposite for effective degradation of methylene blue. Therefore, Ag-ZnO nanocomposite can be regarded as a potential candidate for application in the treatment of waste water.
关键词： Methylene blue,Ag-ZnO nanocomposites,Mechanism,Photocatalysis
更新于2025-09-23 15:23:52