Synthesis of α-Bismuth oxide using solution combustion method and its photocatalytic properties (original) (raw)
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Rasayan Journal of Chemistry, 2019
Bismuth oxide can be synthesized by solution combustion method. One of parameters that must be considered on the synthesis using this method is fuel-oxidant ratio (ϕ) since it influences the physicochemical preperties such as morphology, the particle size and crystal structure of the obtained products which further affect on their photocatalyc activity. This research used citric acid as fuel and Bi(NO 3) 3 .5H 2 O as oxidant. This study aims to investigate impact of citric acid-bismuth nitrate pentahydrate (fuel-oxidant) ratio on the physichochemical properties and photocatalytic activity of the obtained products on degradation of methyl orange. The results showed that all the obtained products contained the mixture of α-Bi 2 O 3 (monoclinic) dan β-Bi 2 O 3 (tetragonal) with irregular shape coral reef-like and in aglomerate form. In addition, the fuel-oxidant ratio does influence the products' particle size in which the particle size of the products prepared by a ratio of ϕ>1, ϕ=1, and ϕ<1 are about 5-8 μm, 6-10 μm, dan 9-14 μm, consecutively. Result of photocatalytic activity shows product synthesized with a ratio of > 1 has the highest photocatalytic activity.
Synthesis of room temperature bismuth oxide and its photocatalytic activity
Materials Letters, 2012
A simple room temperature chemical route is selected for the preparation of phase pure bismuth oxide (Bi 2 O 3) without applying any post heat treatment. The phase pure form of Bi 2 O 3 is confirmed from X-ray diffraction. The surface morphology of the powder is observed by a scanning electron microscope and it reveals that the powder consists of agglomerates. The photocatalytic activity of Bi 2 O 3 is evaluated by photocatalytic decolorization of methyl orange aqueous solution for 2 h. The crystallite size dependence of degradation is confirmed by annealing the sample at two different temperatures (200 and 600 1C) for 2 h. The photocatalytic degradation property of Bi 2 O 3 varies with the crystallite size. The degradation percentage of MeO using Bi 2 O 3 as catalyst are 76%, 52% and 24% for the as-prepared and the annealed sample at 200 and 600 1C respectively.
Open Chemistry, 2020
Synthesis of bismuth oxide synthesis through the precipitation method using H2C2O4 and Na2CO3 precipitating agents, identification of physicochemical properties and its photocatalysis activity for methyl orange degradation were conducted. The bismuth oxide synthesis was undertaken by dissolving Bi(NO3)3.5H2O in HNO3, then added precipitating agents to form precipitate. The results showed that bismuth oxide produced by H2C2O4 precipitating agent was a yellow powder containing a mixture of α-Bi2O3 (monoclinic) and β-Bi2O3 (tetragonal), porous with size of 28-85 μm. Meanwhile, the use of Na2CO3 as precipitating agent resulted in bismuth oxide consisting of α-Bi2O3 and β-Bi2O3 and Bi2O4, irregular shape without pore being 40-115 μm in size. Bismuth oxide synthesized with H2C2O4 precipitating agent showed higher photocatalytic activity compared to bismuth oxide synthesized using Na2CO3 on degrading methyl orange dye with degradation rate constants of 2.35x10-5 s-1 for H2C2O4 and 1.81x10-...
Indonesian Journal of Chemistry, 2020
Research on synthesis of bismuth oxide (Bi2O3) using sol-gel method with varying calcination temperatures at 500, 600, and 700 °C has been done. This study aims to determine the effect of calcination temperature on the characteristics of the obtained products which encompasses crystal structure, surface morphology, band-gap energy, and photocatalytic activity for the decolorization of methyl orange dyes through its kinetic study. Bismuth oxide prepared by sol-gel method was undertaken by dissolving Bi(NO3)3·5H2O and citric acid in HNO3. The mixture was stirred then heated at 100 °C. The gel formed was dried in the oven and then calcined at 500, 600, and 700 °C for 5 h. The obtained products were a pale yellow powder, indicating the formation of bismuth oxide. This is confirmed by the existence of Bi–O and Bi–O–Bi functional groups through FTIR analysis. All three products possess the same mixed crystal structures of α-Bi2O3 (monoclinic) and γ-Bi2O3 (body center cubic), but their mor...
Bulletin of Chemical Reaction Engineering & Catalysis
Bismuth oxide (Bi2O3) is a well-studied photocatalyst for degradation of various environmental contaminants. In this research Bi2O3 has been synthesized by precipitation method using two different bases (NH4OH and NaOH). The samples thus obtained were then analyzed using FTIR, XRD, and SEM for surface functionalization, crystal structures and morphological differences, respectively. The Bi2O3 precipitated using NH4OH showed a flower like structure made up of individual plates having α-Bi2O3 crystal structure. The precipitate obtained using NaOH showed a honeycomb like flower structure with a mixture of both α-Bi2O3 and γ-Bi2O3 crystal structure. Degradation of methyl orange (MO) was used as a model system to test the photocatalytic activity of the bismuth oxide. The Bi2O3 synthesized using NH4OH showed superior photocatalytic degradation of methyl orange than the one synthesized using NaOH. Copyright © 2017 BCREC Group. All rights reservedReceived: 12nd April 2017; Revised: 24th Jun...
Key Engineering Materials, 2017
Azo dyes are usually used in textile industry. However, they can cause water contamination, lead to water pollution, damage to aquatic lives and degenerate scenery due to their toxicity. These problems can be overcome by photocatalytic process in which the azo dyes are converted to CO2 and water. This research concentrates on effect of Bi2O3, BiOBr and BiOI contents on titanium dioxide substance (TiO2) for the photocatalytic process. In the study, photocatalysts were synthesized by sol-gel and wetness impregnation methods. They were studied in surface area by BET technique, chemical composition by FT-IR spectroscopy and optical properties by UV-DRS technique. Increase in bismuth content on TiO2 results in decreasing surface area. In FT-IR spectra, Ti-O-Ti stretching bands at 400-800 cm-1 were detected. The band gap energy of these photocatalysts is decreased when bismuth was doped. Since efficiency of CO2 and water conversion of the photocatalysts can be determined indirectly via de...
DESALINATION AND WATER TREATMENT
Bismuth oxide is a semiconductor metal oxide that can be synthesized by the solution combustion method. The purpose of this research is to synthesize bismuth oxide pertaining to variations in the fuel-oxidant ratio and determine the characteristics and the photocatalytic activity of bismuth oxide for the degradation of organic dye molecules including remazol black B, methyl orange and rhodamine B. The resulting products synthesized with the three ratios φ > 1, φ = 1, and φ < 1 were in the form of yellow powder. Fourier-transform infrared spectroscopy results of the three samples showed the presence of Bi-O-Bi and Bi-O functional groups indicating that Bi 2 O 3 was formed. Moreover, X-ray diffractogram indicated that Bi 2 O 3 particles contained in all samples were a mixture of α-Bi 2 O 3 and β-Bi 2 O 3 phases. Coral reef-like morphology was observed in all samples with Bi 2 O 3 φ = 1 having the smallest particle size followed by φ > 1 and φ < 1. Furthermore, Bi 2 O 3 with φ > 1, φ = 1, and φ < 1 have band gaps of 2.584, 2.581 and 2.625 eV, respectively. The photocatalytic activity test showed that bismuth oxide synthesized with the ratio φ = 1 showed the best photocatalytic activity compared to φ > 1 and φ < 1 in the three different organic dye molecules, namely remazol black B, methyl orange, and rhodamine B.
Preparation of Bismuth Oxide Photocatalyst and Its Application in White-light LEDs
Journal of Nanomaterials, 2013
Bismuth oxide photocatalysts were synthesized and coated on the front surface of phosphor-converted white light-emitting diodes to produce a safe and environmentally benign lighting source. Bismuth oxide photocatalyst powders were synthesized with a spray pyrolysis method at 500°C, 600°C, 700°C, and 800°C. Using the absorption spectrum in the blue and UV regions of the bismuth oxide photocatalysts, the blue light and UV leakage problems of phosphor-converted white LEDs can be significantly reduced. The experimental results showed that bismuth oxide photocatalyst synthesized at 700°C exhibited the most superior spectrum inhibiting ability. The suppressed ratio reached 52.33% in the blue and UV regions from 360 to 420 nm. Related colorimetric parameters and the photocatalyst decomposition ability of fabricated white-light LEDs were tested. The CIE chromaticity coordinates(x,y)were (0.349, 0.393), and the correlated color temperature was 4991 K. In addition, the coating layer of photoc...
Bismuth titanate (Bi 4 Ti 3 O 12 and Bi 12 TiO 20) powders were synthesized by the Oxidant Peroxide Method (OPM), and the effect of temperatures on physical and chemical properties of particles was investigated. The results showed that the morphology and average particle size of materials can be successfully controlled by adjusting the temperature. The samples after calcination were characterized by X-ray diffrac-tometry, transmission electron microscopy, diffuse reflectance spectroscopy, Raman spectroscopy, and BET isotherms. The photocatalytic activity of materials was also evaluated by studying the degradation of 10 ppm aqueous rhodamine B dye under ultraviolet radiation.
Sputtered bismuth oxide thin films as a potential photocatalytic material
Catalysis Today, 2016
Bismuth oxide (Bi 2 O 3) thin films were deposited using a magnetron sputtering system under different conditions of power (radio frequency) and substrate temperature. The film structural characterization was done using X-ray diffraction, where it was demonstrated that films presenting different crystalline phases were obtained; cubic delta-Bi 2 O 3 and a mixture of ␣and -Bi 2 O 3 in different proportions. Three of these films were selected to compare their photocatalytic activity by measuring the percentage of photodiscoloration of 1 × 10 −6 M of methyl orange (MO, C 14 H 4 N 3 SO 3 Na) using UV light; moreover, the effect of the pH of the solution on the photodiscoloration was also investigated. The results indicated that the films were only active under acidic pH and that the cubic delta phase was the most efficient. The optical properties were also evaluated by ellipsometric spectroscopy and the results were compared to the optical transmittance spectroscopy. In order to gain understanding about the effect of the pH and the structure, the point of zero charge and the photoluminescence of the three samples were also obtained. Furthermore, the photocatalytic activity of the sample presenting the best results was evaluated using higher concentration of the MO dye, but also using indigo carmine dye and both UV and blue lights.