- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Synthesis of oxygen deficient bismuth oxide photocatalyst for improved photoelectrochemical applications
摘要： The present paper reports the effect of nitrogen modification on photoelectrochemical (PEC) water oxidation behavior of Bi2O3 semiconductor thin film. The semiconductor particles were synthesized via hydrothermal route using Bi(NO3)3 as a Bi3+ ion precursor and urea as the nitrogen source followed by drop-cast the particles and annealing the film at 600oC. The synthesized Bi2O3 exhibited band gap energy of 3.01 eV, calculated from the UV-vis absorption spectrum which decreases to 2.75eV through N-modification. Water oxidation behavior of the material has been tested through linear sweep voltammetry under periodic illumination. Highest photo-current of 180 μAcm-2 has been measured for water oxidation reaction at 0.95V vs. Ag/AgCl, under illumination of 35mWcm-2. N-incorporation can enhance the photocurrent up to 50% whereas the visible responsiveness of the material improves significantly as confirmed from electrochemical action spectra and UV-visible absorption spectra. The photocatalytic activity of the semiconductor particles was confirmed through decoloration of Rhodamine-B dye, by spectrophotometric measurements.
关键词： Hydrothermal synthesis,Oxygen vacancies,Bismuth oxide photocatalyst,PEC water oxidation.,N-modification
更新于2025-09-23 15:22:29
-
Effects of Milling Time, Zirconia Addition, and Storage Environment on the Radiopacity Performance of Mechanically Milled Bi2O3/ZrO2 Composite Powders
摘要： Mineral trioxide aggregate (MTA) typically consists of Portland cement (75 wt.%), bismuth oxide (20 wt.%), and gypsum (5 wt.%) and is commonly used as endodontic cement. Bismuth oxide serving as the radiopacifying material reveals the canal filling effect after clinical treatment. In the present study, bismuth/zirconium oxide composite powder was prepared by high energy ball milling of (Bi2O3)100?x (ZrO2)x (x = 5, 10, 15, and 20 wt.%) powder mixture and used as the radiopacifiers within MTA. The crystalline phases of the as-milled powders were examined by the X-ray diffraction technique. The radiopacities of MTA-like cements prepared by using as-milled composite powders (at various milling stages or different amount of zirconia addition) were examined. In addition, the stability of the as-milled powders stored in an ambient environment, an electronic dry box, or a glove box was investigated. The experimental results show that the as-milled powder exhibited the starting powder phases of Bi2O3 and ZrO2 and the newly formed δ-Bi7.38Zr0.62O2.31 phase. The longer the milling time or the larger the amount of the zirconia addition, the higher the percentage of the δ-Bi7.38Zr0.62O2.31 phase in the composite powder. All the MTA-like cements prepared by the as-milled powder exhibited a radiopacity higher than 4 mmAl that is better than the 3 mmAl ISO standard requirement. The 30 min as-milled (Bi2O3)95(ZrO2)5 composite powder exhibited a radiopacity of 5.82 ± 0.33 mmAl and degraded significantly in the ambient environment. However, storing under an oxygen- and humidity-controlled glove box can prolong a high radiopacity performance. The radiopacity was 5.76 ± 0.08 mmAl after 28 days in a glove box that was statistically the same as the original composite powder.
关键词： mineral trioxide aggregates,radiopacity,bismuth oxide,mechanical milling,zirconia
更新于2025-09-19 17:13:59
-
Fabrication of functionalized plasmonic Ag loaded Bi2O3/montmorillonite nanocomposites for efficient photocatalytic removal of antibiotics and organic dyes
摘要： From the viewpoint of practical application, the development of photocatalyst having strong light harvesting and effective charge separation as well as using abundant natural mineral as photocatalyst substrate would be very promising. In this work, a novel Ag loaded Bi2O3/montmorillonite nanocomposite has been successfully prepared by a facile thermal and impregnation methods for the first time to study its photocatalytic performance for aqueous pollutant decomposition under the visible light irradiation. Interestingly, the Ag loaded Bi2O3/montmorillonite nanocomposite presented excellent visible light induced photocatalytic activities for tetracycline (TC) antibiotic and RhB degradation, which is much superior over those of solely Bi2O3, montmorillonite and the corresponding composite. The superiority photocatalytic performance of Ag loaded Bi2O3/montmorillonite nanocomposite over other samples should be due to the improved visible light absorption, enlarged specific surface area and enhanced charge separation. In addition, the effect of different factors such as dosage of composite, pollutants concentration and pH of the pollutant solution on the photocatalytic activity of the composite was inspected. Finally, the possible photocatalytic mechanism of Ag loaded Bi2O3/montmorillonite nanocomposite towards pollutants was proposed in detail based on the trapping experiment and ESR test. The as-developed composite provides a new high efficiency of photocatalyst for potential applications in refinement antibiotic pollutants from wastewater.
关键词： Silver nanoparticle,Photocatalytic activity,Bismuth oxide,Montmorillonite,Mechanism
更新于2025-09-12 10:27:22
-
BIFEVOX Composites: Manufacture and Characterization
摘要： Design of composites is a way to improve the quality of solid electrolytes. By mechanically mixing and annealing substituted bismuth vanadate with nanosized aluminum, bismuth, and zirconium binary oxides, we obtained heterogeneous materials Bi4V1.7Fe0.3O11 – δ/xAl2O3, Bi4V1.7Fe0.3O11 – δ/xBi2O3, and Bi4V1.7Fe0.3O11 – δ/xYSZ. The investigation tools were X-ray powder diffraction and electron microscopy with energy-dispersive microanalysis. The composition of materials was studied, the non-interaction of components was elucidated in the aluminum oxide and zirconium oxide composite series, and a nonuniform distribution of nanopowder particles across the surfaces and cleaves of sinters was discovered. The bismuth atoms from bismuth oxide were shown to be capable of incorporating into the Bi4Fe0.3V1.7O11 – δ structure. The charge transport characteristics of the materials were studied by impedance spectroscopy. No changes were observed in logσ–103/T trends in composites with various binary oxides and various oxide contents. An increase in binary oxide concentration was shown to give rise to an insignificant decay in electrical conductivity.
关键词： composite materials,bismuth vanadates,impedance spectroscopy,bismuth oxide,oxygen-ion conductors
更新于2025-09-10 09:29:36
-
Synthesis of nanocrystalline bismuth oxide and its visible photocatalytic activity in the degradation of an organic dye
摘要： Bismuth oxide powder was synthesized, characterized and employed as a visible light photocatalyst for the degradation of aqueous solutions of Orange G (OG), a mono azo dye that is a commonly used colouring agent in various industrial applications. A simple combustion method using urea as fuel was employed to synthesize the metal oxide nanopowders. The prepared material was found to be nanocrystalline in nature as confirmed by XRD analysis. The band gap energy of the material is calculated by plotting (Ah(cid:1))2 vs. h(cid:1) from the UV-DRS spectrum and it is found to be 2.7 eV. The surface morphology and roughness of the material was studied by FE-SEM and AFM techniques. XPS and EDAX studies confirmed the elemental purity and presence in the nanomaterial. Preliminary studies were carried out in order to optimize the solution pH, catalyst dosage and initial dye concentration. As the catalyst possessed good activity at all pH values, thereafter all the photocatalytic reactions were carried out at neutral pH to make the process less cumbersome and cost effective. An optimum catalyst dosage of 1.5 g/L was fixed for a dye solution of 5 mg/L concentration. Kinetic studies showed the photo-degradation to follow pseudo-first order kinetics. Studies on the effect of electrolytes in solution showed that there was a decrease in the efficiency of the catalyst in the presence of the electrolytes. Reusability studies were performed on the catalyst to estimate the economic viability of the system.
关键词： visible light,combustion method,Bismuth oxide,Orange G,photocatalysis
更新于2025-09-09 09:28:46
-
Photocatalytic Degradation of Gentian Violet with Li Doped Bismuth Oxide Nanorods
摘要： Li doped bismuth oxide nanorods have been synthesized via the hydrothermal route. The obtained nanorods possess semi-circular tips, the length and diameter are 1–5 μm and 50–350 nm, respectively. The photocatalytic activity of the Li doped bismuth oxide nanorods has been analyzed by the photocatalytic degradation of gentian violet (GV). GV with the concentration of 10 mg · mL?1 can be photodegraded totally in the presence of 10 mg Li doped bismuth oxide nanorods under UV light irradiation for 60 min. The photodegradation ratio of the Li doped bismuth oxide nanorods is closely relative to the content of the nanorods and initial GV concentration. The photodegradation ratio decreases obviously with the decrease of the content of the nanorods and increase of initial GV concentration.
关键词： Photocatalysis,Li Doped Bismuth Oxide Nanorods,Gentian Violet,Scanning Electron Microscopy
更新于2025-09-09 09:28:46
-
One pot synthesis of bismuth oxide/graphitic carbon nitride composites with high photocatalytic activity
摘要： A one pot synthesis of heterostructured bismuth oxide (Bi2O3)/graphitic carbon nitride (g-CN) photocatalysts was developed using Bi(NO3)3 and melamine in 1 M HNO3 as precursors. SEM, TEM and XPS analyses demonstrate that Bi2O3 is closely associated to g-CN, producing contacted interfaces between the two materials. The loading in Bi2O3 was varied from 1.25 to 10 wt% and the highest photocatalytic activity was obtained for the composite containing 2.5% BBN. The Bi2O3 (2.5%)/g-CN material exhibits excellent photocatalytic activity under visible light irradiation for the degradation of RhB as well as a good stability and reusability. Reactive species trapping experiments demonstrated that superoxide O2? radicals and to a lesser extent holes play a key role in the decomposition of the dye. The high photocatalytic activity of the Bi2O3 (2.5%)/g-CN composite originates from the effective separation of photogenerated charge carriers, which was confirmed by photoluminescence and photocurrent measurements, and from its high specific surface area (26.1 m2/g). The convenient and low cost method developed for the preparation of g-CN-based photocatalysts is of high interest for the synthesis of new heterostructured materials for environmental remediation.
关键词： Graphitic carbon nitride,Heterostructured photocatalyst,Bismuth oxide
更新于2025-09-04 15:30:14