- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Bandgap Tailored TiO2 Thin Films by Addition of SiO2 for Enhanced Photocatalytic Activity against Congo Red under Visible Light Illumination
摘要： Colloidal solutions of SiO2-TiO2 mixed oxides having different SiO2 contents were synthesized by sol-gel technique and thin films were deposited over glass slides by using dip coating technique. The films were subjected to high temperature at 400 °C for growing TiO2 crystals. Energy dispersive X-ray spectroscopy was used to indicate the elements in the films. X-ray diffraction analysis indicated that SiO2-TiO2 films contain only anatase phase. Scanning electron microscopy was used to study the films surface morphology. The SiO2-TiO2 films that were contacted with congo red (5 ppm) and irradiated with visible light showed a high photocatalytic activity. UV spectrophotometry technique was used to monitor the degradation of congo red by the reduction of main absorbance peak at 497 nm. Complete degradation was achieved after 2 h for 3 mol % SiO2-TiO2 thin film.
关键词： Congo red,SiO2,Dip coating,TiO2,Photocatalytic activity
更新于2025-09-04 15:30:14
-
Solution combustion synthesis of ZnO powders using various surfactants as fuel
摘要： Single phase ZnO powders were synthesized by solution combustion method using various surfactants as fuel. The effects of hydrocarbon tail length on the combustion behavior, phase evolution, morphology, optical properties, and photocatalytic activity were studied by thermal analysis, X-ray diffraction, electron microscopy, and photoluminescence spectroscopy techniques. The specific surface area and pore volume increased with the addition of citric acid as auxiliary fuel due to the increase of released gaseous products. ZnO powders obtained by mixed fuels show higher crystallinity and specific surface area, leading to the higher photodegradation of methylene blue under ultraviolet irradiation. Moreover, the photocatalytic activity increased in the presence of ZnO powders prepared by the longest hydrocarbon tail.
关键词： ZnO,Surfactant,Photocatalytic activity,Porous materials
更新于2025-09-04 15:30:14
-
AIP Conference Proceedings [Author(s) 4TH ELECTRONIC AND GREEN MATERIALS INTERNATIONAL CONFERENCE 2018 (EGM 2018) - Bandung, Indonesia (27–28 July 2018)] - Effects of Ag dopant and ultraviolet irradiation on structural properties of zinc oxide nanostructures
摘要： ZnO nanorods are promising UV light driven photocatalyst for the degradation of organic dyes. In this work, the effects of Ag dopant (0.02 to 0.1 mol%) and ultraviolet irradiation (0 to 6 min) on structural, optical and photocatalytic properties of zinc oxide nanorods were investigate. The Ag incorporation ZnO nanoraod have been grown on glass substrate by chemical solution deposition method. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–vis absorption spectroscopy (UV–vis). The XRD spectra of the Ag incorporation ZnO (Ag-ZnO) films indicate that Ag was incorporated in the wurtzite hexagonal crystal structure of ZnO and the crystallinity were enhanced with increasing of Ag amount as well as ultraviolet irradiation time. SEM micrographs of pure ZnO films revealed the uniform distribution of rod-like nanostructure of size of about 30-40 nm. Increasing Ag amount as well as irradiation time stimulated the optical properties of ZnO nanostructures. The photocatalytic activity of these nanostructures was evaluated by analysing UV irradiation degradation of methyl orange (MO) dye and it was observed that Ag-ZnO show significantly enhanced photocatalytic activity for degradation of MO, as compared to ZnO nanorods.
关键词： structural properties,ZnO nanorods,ultraviolet irradiation,Ag dopant,photocatalytic activity
更新于2025-09-04 15:30:14
-
Synthesis and characterization of morphology-controllable BiFeO3 particles with efficient photocatalytic activity
摘要： The single phase BiFeO3 (BFO) particles were synthetised by a facile hydrothermal method under the special sodium hydroxide (NaOH) concentration. The particles have been systematically characterized by X-ray diffraction technique, ?eld emission scanning electron microscopy, energy dispersive spectrometer, fourier transform infrared spectroscopy and UV–vis spectra. It is found that a wide range of NaOH concentration of 1–3 M could induce a high crystalline quality of BFO. Interestingly, it is noted that di?erent NaOH concentrations have a signi?cant e?ect on the morphology of BFO particles. With the increase of NaOH concentration, the morphology changes from alveolate BFO to cubic BFO particles. Moreover, the light absorption characteristics and the band gap of BFO particles are strongly dependent on their morphology. This result in the di?erence of photocatalytic degradation ability of alveolate BFO particles compared to that of cubic BFO particles.
关键词： Photocatalytic activity,Hydrothermal,Morphologies,BiFeO3
更新于2025-09-04 15:30:14
-
Facile synthesis of Ag/ZnO metal–semiconductor hierarchical photocatalyst nanostructures <i>via</i> the galvanic-potential-enhanced hydrothermal method
摘要： Hierarchical metal–semiconductor nanostructures (NSs) composed of a backbone made of Ag nanowire and ZnO nanorod (NR) branches were successfully prepared using the galvanic-potential-enhanced hydrothermal method. A galvanic cell structure was formed between an Al bottle anode that was used as a hydrothermal reactor and an Ag NW cathode dispersed in a hydrothermal solution. As a result, the contact-potential-driven hydrothermal growth of the ZnO NRs on the sidewalls of the Ag NWs could be achieved. The morphological and microstructure characterization confirmed the formation of well-arranged hierarchical NSs composed of Ag NW trunk and ZnO NR branch structures. The photocatalytic properties of the hierarchical Ag/ZnO NSs were investigated by degrading methylene blue (MB) dye as a model pollutant. It was found that the hierarchical Ag/ZnO NSs demonstrated a more than two-fold faster degradation rate than the pristine ZnO NSs. The high-performance photocatalytic activity of the Ag/ZnO hierarchical NSs was attributed to the synergetic effect of the metallic Ag NWs and the ZnO NRs that enhanced the charge separation and diffusion by suppressing charge recombination, as well as enhanced reaction sites and light absorption.
关键词： methylene blue degradation,Ag/ZnO,photocatalytic activity,hierarchical nanostructures,galvanic-potential-enhanced hydrothermal method
更新于2025-09-04 15:30:14
-
Preparation of ZnO Nanoparticles Under Ultrasonic Irradiation and Photocatalytic Performance of ZnO Nanoparticles Multilayer Films
摘要： Zinc oxide nanoparticles were synthesized by the reaction of an aqueous-alcoholic solution containing zinc nitrate hexahydrate and sodium hydroxide under ultrasonic irradiation at room temperature. The crystallinity, morphology and optical property of ZnO nanoparticles were examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and UV-visible spectrophotometer. Zinc oxide nanoparticles multilayer films were prepared dipping glass slide, which had been cleaned with a piranha solution, into a ZnO solution by ultrasonic irradiation. The ZnO nanoparticles multilayer films were evaluated as a photocatalyst in the photocatalytic degradation of organic dyes, such as methylene blue, methyl orange and rhodamine B, under ultraviolet light at 254 nm.
关键词： Multilayer films,Photocatalytic activity,Zinc oxide nanoparticles,Organic dyes,UV-visible spectrophotometer
更新于2025-09-04 15:30:14
-
Influence of pH-control in phosphoric acid treatment of zinc oxide
摘要： Zinc oxide is often used as a white pigment for cosmetics; however, it shows photocatalytic activity that causes decomposition of sebum on the skin when exposed to the ultraviolet radiation in sunlight. In this work, zinc oxide was reacted with phosphoric acid at various pH values to synthesize a novel white pigment for cosmetics. The chemical composition, powder properties, photocatalytic activities, colors, and smoothness of these pigments were studied. The obtained materials exhibited X-ray diffraction peaks relating to zinc oxide and phosphate after phosphoric acid treatment. The ratio of zinc phosphate to zinc oxide was estimated from inductively coupled plasma - atomic emission spectroscopy results. Samples treated at pH 4-7 yielded small particles with sub-micrometer sizes. The photocatalytic activity of zinc oxide became lower after phosphoric acid treatment. Samples treated at pH 4-7 showed the same reflectance as zinc oxide in both the ultraviolet and visible ranges. Adjustment of the pH was found to be important in the phosphoric acid treatment of zinc oxide.
关键词： zinc oxide,photocatalytic activity,particle size,phosphoric acid treatment
更新于2025-09-04 15:30:14
-
Synthesis of TiO2/SiO2-B2O3 Ternary Nanocomposites: Influence of Interfacial Properties on their Photocatalytic Activities with High Resolution Mass Spectrometry Monitoring
摘要： An investigation on unusual interface properties of unprecedented ternary composites, formed by the inclusion of assorted proportions of B2O3 into TiO2/SiO2 structure, is conducted herein. The influences of B2O3 content and calcination temperature were evaluated. The precursor TiO2/SiO2 material was synthesized via a simple sol-gel procedure that was followed by B2O3 inclusion via maceration and calcination. The materials were fully characterized and their photocatalytic performance to degrade the Indigo Carmine dye investigated. The material prepared with a B/Ti molar ratio of 1 and at calcination temperature of 350 °C (B1-350) showed the best performance, with a superior photocatalytic activity than that of commercial TiO2. The presence of B2O3-TiO2-SiO2 interfaces in the structure of such material was of critical importance in producing a material with these attractive features. Finally, high resolution mass spectrometry monitoring allowed for the characterization of the main degradation products formed under these conditions.
关键词： high resolution mass spectrometry,degradation of Indigo Carmine,B2O3-TiO2-SiO2 ternary nanocomposites,photocatalytic activity,by-products characterization,structural defects
更新于2025-09-04 15:30:14
-
A Study of Controllable Synthesis and Formation Mechanism on Flower-Like TiO2 with Spherical Structure
摘要： The development of photocatalytic materials with specific morphologies promises to be a good opportunity to discover geometrically relevant properties. Herein, this paper reported a facile hydrothermal method to directly synthesize TiO2 crystals with flower-like structures using tetrabutyl titanate (TBT) as a titanium source and ethylene glycol as an additive. We also proposed a reasonable growth mechanism by controlling reaction time in detail. The as-prepared samples were analyzed by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy for structure and morphology characterization. The N2 adsorption-desorption isotherm results showed that the surface area of flower-like TiO2 with 10 h reaction time can reach 297 m2/g. We evaluated the photocatalytic performance of samples by using the degradation rate of methylene blue (MB) solution under UV-vis light. The TiO2 with 10 h reaction time exhibited a superior photocatalytic property than other samples in degrading MB under UV-vis light irradiation. More importantly, the catalyst could be reused many times. These results could benefit from the special morphology, high crystallinity and large specific surface area of the samples.
关键词： flower-like,photocatalytic activity,TiO2
更新于2025-09-04 15:30:14
-
Enhanced Photocatalytic degradation of methylene blue dye using CuS-CdS nanocomposite under visible light irradiation
摘要： The inorganic nanoparticles based semiconductor photocatalyst has attracted widespread attention for the practical applications in sustainable energy and environmental remediation due to its low cost, eco-friendly, high efficiency and ease of process. CuS, CdS and CuS-CdS nanocomposite photocatalysts have been successfully synthesized by a simple hydrothermal approach. The phase purity, composition and surface morphology of as synthesized nanomaterials were characterized using various analytical techniques. The photocatalytic activities of the as-prepared materials have been evaluated by the degradation of methylene blue (MB) dye in the presence of hydrogen peroxide (H2O2) which served as an oxidant under visible light irradiation. MB dye (10 ppm) was degraded by about 80%, 59% and 99.97% for CuS, CdS and CuS-CdS nanocomposite respectively at 10 min. The results demonstrate that CuS-CdS nanocomposite exhibited excellent photocatalytic activity as compared to the CuS and CdS is which mainly attributed to large surface area, narrow band gap, high adsorbing capacity of the dye and also low recombination of the photo-generated electrons and holes. Further, electrochemical impedance (EI) measurement revealed that as prepared CuS-CdS nanocomposite suggested that as compared to CuS and CdS, the CuS-CdS nanocomposite exhibits rapid migration of photo-induced charge carriers. In addition, the CuS-CdS nanocomposite demonstrated that good stability towards photocatalytic degradation even after repeated usage. Finally, a suitable photocatalytic reaction mechanism has been proposed to indicate the photocatalytic performance of the nanocomposite.
关键词： Methylene blue dyes,hydrogen peroxide,CuS-CdS,photocatalytic activity.,charge carrier
更新于2025-09-04 15:30:14