scholarly journals How the Ti Precursor is Involved in the Effectiveness of Pt-TiO2 Materials in Photodegrading Methyl Orange

2021 ◽  
Vol 16 (2) ◽  
pp. 21-30
Author(s):  
Julie Joseane Murcia Mesa ◽  
Mónica Sirley Hernández Laverde ◽  
Hugo Alfonso Rojas Sarmiento ◽  
Mayra Anabel Lara Angulo ◽  
José Antonio Navío ◽  
...  

As other studies have demonstrated, improving the effectiveness of TiO2 for environmental remediation requires that the properties of this oxide be modified using different synthesis methods. In the current study, labprepared TiO2 was synthesized using the hydrothermal method and two different Ti precursors (titanium butoxide and titanium isopropoxide). After the synthesis, the obtained titania was also modified using photodeposition by platinum nanoparticles. This study aims to evaluate the effectiveness of the photocatalytic materials prepared in photodegrading methyl orange. The Ti precursors used in the TiO2 synthesis had a slight effect on the physicochemical properties of the oxide obtained. When titanium butoxide was used as a precursor, we observed a change in the bandgap value and some material with the largest surface area. Additionally, the addition of Pt increased the absorption of TiO2 in the visible region of the electromagnetic spectrum and slightly decreased the bandgap value of this oxide. The photocatalyst prepared using titanium isopropoxide as a precursor showed the most remarkable effectiveness in the degradation rate of methyl orange. This is the result of the lower band gap value of this material which leads to easier transport of the photogenerated charges during the photocatalytic reaction. We also observed that the addition of Pt has a detrimental effect on the effectiveness of TiO2 in dye degradation, which may be due to possible obstruction of the dye-photocatalyst interaction on the TiO2 surface because of the Pt nanoparticles observed by tem. The effectiveness of commercial TiO2 in methyl orange degradation is slightly higher than that observed in other evaluated solids.

2018 ◽  
Vol 79 (5) ◽  
pp. 947-957 ◽  
Author(s):  
Mahabubur Chowdhury ◽  
Sarah Kapinga ◽  
Franscious Cummings ◽  
Veruscha Fester

Abstract Advanced oxidation processes based on sulphate radical generated by peroxymonosulphate (PMS) activation is a promising area for environmental remediation. One of the biggest drawbacks of heterogeneous PMS activation is catalyst instability and metal ion leaching. In this study, a simple organic binder mediated route was explored to substitute Ti4+ ions into the Co3O4 host lattice structure to create a Co-O-Ti bond to minimise cobalt leaching during methyl orange degradation. The catalyst was characterised by X-ray diffraction, and scanning and transmission electron microscopy. The as-prepared catalysts with Co3O4:TiO2 ratio of 70:30 exhibited minimal leaching (0.9 mg/L) compared to other ratios studied. However, the pristine Co3O4 exhibited highest catalytic activity (rate constant = 0.41 min−1) and leaching (26.7 mg/L) compared to composite material (70:30 Co3O4:TiO2). Interestingly, the morphology of the composite and leaching of Co2+ ions were found to be temperature dependent, as an optimum temperature ensured strong Co-O-Ti bond for prevention of Co2+ leaching. The classical quenching test was utilised to determine the presence and role of radical species on methyl orange degradation. The fabricated catalyst also exhibited good catalytic activity in degrading mixed dyes and good recyclability, making it a potential candidate for commercial application.


2020 ◽  
Vol 16 ◽  
Author(s):  
Nimisha Jadon ◽  
Gulzar Ahmad Bhat ◽  
Manoharmayum Vishwanath Sharma ◽  
Harendra Kumar Sharma

Background: The study focuses on the synthesis of chitosan/ Fe2O3 nanocomposite, its characterization and application in methyl orange dye degradation. Methods: The synthesized chitosan/ Fe2O3 nanocomposite was characterized with Powder X-Ray Diffraction, Fourier Transformation Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and UV-Vis Spectroscopy. Results: The characterization showed that the Fe2O3nanoparticles were embedded in the polymer matrix of chitosan. The size of the Fe2O3nanoparticles were less than 10nm and the crystallite size was 1.22 nm.The synthesized chitosan/ Fe2O3nanocomposite was tested for methyl orange degradation using different parameters such as effect of contact time, effect of dose, effect of concentration and effect of pH for the degradation of methyl orange dye in aqueous solution.The Fruendlich, Langmuir and Temkin isotherm studies were also conducted for adsoption of methyl orange on Chitosan/ Fe2O3nanocomposite. Conclusion: The study indicated that the synthesized chitosan/Fe2O3 nanocomposite had the potential of degrading methyl orange dye up to 75.04% under the set condition in this experiment which indicate that Chitosan/ Fe2O3 nanocomposite is a viable option that can be used for the degradation of methyl orange dye.


2012 ◽  
Vol 488-489 ◽  
pp. 98-102
Author(s):  
Tanagorn Kwamman ◽  
Siwaporn Meejoo Smith

A low temperature solvothermal method was employed to synthesize nitrogen-fluorine doped TiO2 materials (N/F -TiO2) at various mole ratio of Ti:F; 10:1, 10:0.3 and 10:0.1, for photocatalytic applications. Doping fluorine and nitrogen in the TiO2 structure extend the spectra response of the materials toward a visible region resulting in the high efficiency to oxidize methyl orange (MO) under UV-Vis irradiation. The microstructure and photocatalytic activity of the materials appeared to depend on titanium precursors, titanium isopropoxide (TTIP) or tetrabutyl orthotitanate (TBOT), and the concentration of dopant (NH4F). The highest MO decolorization efficiency under UV-Vis irradiation for 30 minutes is about 86 % by using N-F-TiO2 (TTIP precursor) with Ti: F of 10: 3 as catalyst. The decolorization efficiencies of MO over N-F-TiO2 materials (TTIP precursor) are twice higher than that of the undoped catalyst.


2020 ◽  
Vol 4 (2) ◽  
pp. 48 ◽  
Author(s):  
Gajanan Kale ◽  
Sudhir Arbuj ◽  
Ujjwala Chothe ◽  
Supriya Khore ◽  
Latesh Nikam ◽  
...  

A highly crystalline ordered Cu-TiO2 nanostructure was synthesized using a simple paper template method using cupric nitrate and titanium isopropoxide as precursors. The structural study by XRD confirmed the formation of highly crystalline anatase phase of Cu-TiO2. The broad diffraction peaks of Cu-TiO2 exhibit the nanocrystalline nature of the product. The optical study by UV-DRS indicated the red shift in absorption wavelength with an increase in Cu doping, i.e., towards the visible region. The FE-SEM and FE-TEM study validated the formation of spherical shaped nanoparticles of Cu-TiO2 having sizes in the range of 20–30 nm. Considering the absorption in the visible region, the photocatalytic study was performed for water splitting and rhodamine-B (RhB) dye degradation under natural sunlight. The 2% Cu-doped TiO2 showed the highest photocatalytic hydrogen evolution, i.e., 1400 µmol·g−1·h−1 from water, among the prepared compositions. The photocatalytic performance of Cu-TiO2 conferred complete degradation of RhB dye within 40 min. The higher activity in both cases was attributed to the formation of highly crystalline ordered nanostructure of Cu-doped TiO2. This synthesis approach has potential to prepare other highly crystalline ordered nanostructured semiconductors for different applications.


Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2206
Author(s):  
Gaoqian Yuan ◽  
Gen Zhang ◽  
Kezhuo Li ◽  
Faliang Li ◽  
Yunbo Cao ◽  
...  

Loading a noble metal on Bi4Ti3O12 could enable the formation of the Schottky barrier at the interface between the former and the latter, which causes electrons to be trapped and inhibits the recombination of photoelectrons and photoholes. In this paper, AgPt/Bi4Ti3O12 composite photocatalysts were prepared using the photoreduction method, and the effects of the type and content of noble metal on the photocatalytic performance of the catalysts were investigated. The photocatalytic degradation of rhodamine B (RhB) showed that the loading of AgPt bimetallic nanoparticles significantly improved the catalytic performance of Bi4Ti3O12. When 0.10 wt% noble metal was loaded, the degradation rate for RhB of Ag0.7Pt0.3/Bi4Ti3O12 was 0.027 min−1, which was respectively about 2, 1.7 and 3.7 times as that of Ag/Bi4Ti3O12, Pt/Bi3Ti4O12 and Bi4Ti3O12. The reasons may be attributed as follows: (i) the utilization of visible light was enhanced due to the surface plasmon resonance effect of Ag and Pt in the visible region; (ii) Ag nanoparticles mainly acted as electron acceptors to restrain the recombination of photogenerated electron-hole pairs under visible light irradiation; and (iii) Pt nanoparticles acted as electron cocatalysts to further suppress the recombination of photogenerated electron-hole pairs. The photocatalytic performance of Ag0.7Pt0.3/Bi4Ti3O12 was superior to that of Ag/Bi4Ti3O12 and Pt/Bi3Ti4O12 owing to the synergistic effect between Ag and Pt nanoparticles.


RSC Advances ◽  
2021 ◽  
Vol 11 (22) ◽  
pp. 13386-13395
Author(s):  
Chaozhong Sun ◽  
Xiaoying Guo ◽  
Changzheng Hu ◽  
Laijun Liu ◽  
Liang Fang ◽  
...  

Searching for a new approach in environmental remediation in terms of dye degradation is important in industrialized society.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3918
Author(s):  
Ratshilumela S. Dima ◽  
Lutendo Phuthu ◽  
Nnditshedzeni E. Maluta ◽  
Joseph K. Kirui ◽  
Rapela R. Maphanga

Titanium dioxide (TiO2) polymorphs have recently gained a lot of attention in dye-sensitized solar cells (DSSCs). The brookite polymorph, among other TiO2 polymorphs, is now becoming the focus of research in DSSC applications, despite the difficulties in obtaining it as a pure phase experimentally. The current theoretical study used different nonmetals (C, S and N) and (C-S, C-N and S-N) as dopants and co-dopants, respectively, to investigate the effects of mono-doping and co-doping on the electronic, structural, and optical structure properties of (210) TiO2 brookite surfaces, which is the most exposed surface of brookite. The results show that due to the narrowing of the band gap and the presence of impurity levels in the band gap, all mono-doped and co-doped TiO2 brookite (210) surfaces exhibit some redshift. In particular, the C-doped, and C-N co-doped TiO2 brookite (210) surfaces exhibit better absorption in the visible region of the electromagnetic spectrum in comparison to the pure, S-doped, N-doped, C-S co-doped and N-S co-doped TiO2 brookite (210) surfaces.


2020 ◽  
Vol 18 (1) ◽  
pp. 129-137
Author(s):  
Yayuk Astuti ◽  
Rizka Andianingrum ◽  
Abdul Haris ◽  
Adi Darmawan ◽  

AbstractSynthesis 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 1.81x10-5 s-1 for Na2CO3.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Xiujuan Qin ◽  
Li Cui ◽  
Guangjie Shao

Ti-doped ZnO sol-composite films were prepared on the glass substrate by the two-step sol-gel technique. X-ray diffraction, Uv-Vis spectrophotometer, and FS spectrum of composite films were used to help make structure characterization and optical performance testing. The results showed that the composite was a mixture of ZnO + Zn2TiO4. Because of synergistic effect of both semiconductor oxides, composite films had a wide range of spectral response in the visible region, and the absorption band edge was about 510 nm, and the Green Belt of composite films luminous significantly enhanced. Photocatalytic oxidation experiments showed that using the composite films treatment (16.5 ml, l0 mg/L methyl orange aqueous solution)/cm2, the decolorization rate of methyl-orange was 90% after 3 hours irradiation.


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