scholarly journals Bismuth Oxide Prepared by Sol-Gel Method: Variation of Physicochemical Characteristics and Photocatalytic Activity Due to Difference in Calcination Temperature

2020 ◽  
Vol 21 (1) ◽  
pp. 108
Author(s):  
Yayuk Astuti ◽  
Brigita Maria Listyani ◽  
Linda Suyati ◽  
Adi Darmawan

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 morphologies and band gap values are different. The higher the calcination temperature, the larger the particle size and the smaller the band gap value. The accumulative differences in characteristics appoint SG700 to have the highest photocatalytic activity compared to SG600 and SG500 as indicated by its percent degradation value and decolorization rate constant.

2012 ◽  
Vol 545 ◽  
pp. 157-160 ◽  
Author(s):  
Nurhanna Badar ◽  
Nor Fadilah Chayed ◽  
Rusdi Roshidah ◽  
Norashikin Kamarudin ◽  
Norlida Kamarulzaman

In this work, the band gap energies of magnesium oxide (MgO) were investigated to see if calcination time affects the band gap energies of the MgO. MgO nanomaterials have been prepared by a sol-gel method. MgO precursors produced were calcined at a temperature of 600 °C for 24 hours and 48 hours. The structural characterization of samples is achieved using X-Ray Diffraction (XRD) and the morphology as well as particle size of MgO were examined by Field Emission Scanning Electron Microscopy (FESEM). UV-Vis NIR spectroscopy was used to determine the band gap energies of the materials. From the results, the band gap energy of the MgO with a longer heating time exhibited a higher value.


2014 ◽  
Vol 875-877 ◽  
pp. 251-256 ◽  
Author(s):  
Lin Sun ◽  
Rong Shao ◽  
Lan Qin Tang ◽  
Zhi Dong Chen

Ag/ZnO nanocomposite photocatalysts with high photocatalytic performance were successfully synthesized via a facile sol-gel method. The prepared Ag/ZnO products were characterized by XRD, SEM, EDS, FT-IR, BET surface area, TG and DSC. Photodegradation experiments of the samples were carried out by choosing Methylene Blue (MB) as a model target under UV irradiation with homemade photocatalytic apparatus. Among these products, when the molar ratio of Ag to ZnO was fixed at 0.07 and the calcination temperature was around 450 °C, the obtained samples exhibited the highest photocatalytic activity.


2017 ◽  
Vol 17 (2) ◽  
pp. 65
Author(s):  
Achmad Sholikhudin Almu’minin ◽  
Tanti Haryati ◽  
Tri Mulyono

TiO2 photocatalyst is one of type semiconductor that is often used in textile dyes photodegradationmethod which characteristics are influenced by the size of crytal. Synthesis of TiO2 photocatalystscan be done by several methods, one using the sol-gel method. By treating variations in thecomposition of the reactans and treatment of synthesis in sol-gel method, the size of the TiO2crystals can be controlled to produced the desired characteristics. This study has been made ofTiO2 photocatalysts in the form of thin-layer films using sol-gel method with annealing process ata temperature of 550oC. This study examines the effect of the concentration of precursor TTIP andhydrolysis ratio of the crystal structure, crystallinity, the band gap energy, and photocatalystactivity to degrade procion red mx-8b dye compound. The result obtained is known that the crystalsynthesized has structure of TiO2 anatase. Value crystal size, crystallinity, the band gap energy,and percent degradation has a value that depends on the composition of TTIP concentration andhydrolysis ratio. Although the results showed morphology of TiO2 particle indivcate that large sizeand crystallinity value is still low, but that is interesting each of the measurement results mutuallysupport each other.Keywords: photocatalyst, TiO2, Sol-gel, TTIP concentration, hydrolysis ratio


2019 ◽  
Vol 2 (01) ◽  
pp. 10-12
Author(s):  
Linda J Kusumawardani ◽  
Yulian Syahputri

In this study, Fe/TiO2 powder was synthesized by sol-gel method using mixture of Titanium Tetraisopropoxide (TTIP) as precursor and FeCl3 as iron source of 10% (w/w). The Fe/TiO2 powder was calcined at 500 °C for 1 hour. The sample of Fe/TiO2 was characterized using FTIR anad DRS measurements. FTIR analysis showed that Fe was successfully doped on TiO2 and then DRS analysis proved that the visible light was absorbed by Fe/TiO2 with its band gap energy up to 2.3 eV


2019 ◽  
Vol 9 (3) ◽  
pp. 362-370 ◽  
Author(s):  
D. Vaya ◽  
Meena ◽  
B.K. Das

Background: The properties of the material are altered when material size shifted towards nano-regime. This feature could be used for wastewater treatment process using model pollutant such as dyes. Recently, nanoparticles are synthesized by a green chemical route using different capping agents. This is the reason we adopt starch as green capping agent along with sol-gel method. Objective: To synthesize cobalt oxide nanoparticles by green chemical route and utilized it in degradation of dyes. Methods: Synthesis of cobalt oxide nanoparticles by sol-gel method using starch as a capping agent. The characteristics of surface modifications were investigated by UV-VIS, TEM, SEM, XRD and FTIR techniques. Results: Cobalt oxide nanoparticles synthesized and inhibited photocatalytic activity. Conclusion: Deactivation of photocatalytic activity due to complex nature of starch. This property can be used elsewhere as in light shielding applications to coat and protect surfaces in order to keep them cool and safe from damage as in the painting of vehicles, roofs, buildings, water tanks, etc.


RSC Advances ◽  
2018 ◽  
Vol 8 (13) ◽  
pp. 6752-6758 ◽  
Author(s):  
Yuanyang Wang ◽  
Yinghua Zhang ◽  
Haiqiang Lu ◽  
Yanxin Chen ◽  
Zhenmin Liu ◽  
...  

Two new types of N-doped ZrO2 photocatalysts ZON and AZON have been synthesized using ethylenediamine as the nitrogen source by a facile and low-cost sol–gel method.


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