Enhanced reactivity of peroxo-modified surface of titanium dioxide nanoparticles used to synthesize ultrafine bismuth titanate powders at lower temperatures

Francatto, P.; Neto, Francisco Nunes Souza; Nogueira, André E.; Kubo, Andressa Mayumi; Ribeiro, Lucas S.; Gonçalves, Lidiane Patricia; Gorup, Luiz Fernando; Leite, E. R.; Camargo, Emerson R.

doi:10.1016/j.ceramint.2016.07.039

Cited by 13 publications

(7 citation statements)

References 43 publications

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“… 34 , 35 However, although the typical particle size of Ti(OH) 4 is 5 nm, they can form large agglomerates of up to approximately 800 nm depending on the amount of material added into the system. 18 , 19 , 22 This could explain the behavior of the intracellular ROS measurement found in the present study, since the highest concentrations tested can clump together, reducing the apparent catalytic surface area, consequently producing less ROS, as demonstrated in the literature data. 31 , 34 …”

Section: Resultssupporting

confidence: 80%

“…Figure shows that the amount of ROS in MB49 cells exposed to a concentration of 0.5 mg/mL of Ti(OH) 4 was significantly higher compared to the untreated control group. This apparent difference in the relative amounts of ROS can be explained by the specific surface area of nanometric materials. − Usually, atoms at the surface of nanoparticles exhibit higher energy than those localized on the surface of conventional materials due to the elevated number of unsatisfied chemical bonds. , However, although the typical particle size of Ti(OH) 4 is 5 nm, they can form large agglomerates of up to approximately 800 nm depending on the amount of material added into the system. ,, This could explain the behavior of the intracellular ROS measurement found in the present study, since the highest concentrations tested can clump together, reducing the apparent catalytic surface area, consequently producing less ROS, as demonstrated in the literature data. , …”

Section: Resultsmentioning

confidence: 64%

“…Although PDT is one of the least invasive therapies, it still poses a challenge in treating certain types of malignant neoplasms with low local oxygen availability . The development of a new class of PS that can exert an oxygen-independent antitumor effect could increase the efficacy of PDT. , The photocatalytic properties of conventional TiO 2 made it widely popular for a variety of applications . Depending on the morphological state, the characteristics of TiO 2 can change the way it interacts with biological molecules, hence, determining its cytotoxic capacity…”

Section: Resultsmentioning

confidence: 99%

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Modified Titanium Dioxide as a Potential Visible-Light-Activated Photosensitizer for Bladder Cancer Treatment

et al. 2022

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Low oxygen concentration inside the tumor microenvironment represents a major barrier for photodynamic therapy of many malignant tumors, especially urothelial bladder cancer. In this context, titanium dioxide, which has a low cost and can generate high ROS levels regardless of local O 2 concentrations, could be a potential type of photosensitizer for treating this type of cancer. However, the use of UV can be a major disadvantage, since it promotes breakage of the chemical bonds of the DNA molecule on normal tissues. In the present study, we focused on the cytotoxic activities of a new material (Ti(OH) 4 ) capable of absorbing visible light and producing high amounts of ROS. We used the malignant bladder cell line MB49 to evaluate the effects of multiple concentrations of Ti(OH) 4 on the cytotoxicity, proliferation, migration, and production of ROS. In addition, the mechanisms of cell death were investigated using FACS, accumulation of lysosomal acid vacuoles, caspase-3 activity, and mitochondrial electrical potential assays. The results showed that exposure of Ti(OH) 4 to visible light stimulates the production of ROS and causes dose-dependent necrosis in tumor cells. Also, Ti(OH) 4 was capable of inhibiting the proliferation and migration of MB49 in low concentrations. An increase in the mitochondrial membrane potential associated with the accumulation of acid lysosomes and low caspase-3 activity suggests that type II cell death could be initiated by autophagic dysfunction mechanisms associated with high ROS production. In conclusion, the characteristics of Ti(OH) 4 make it a potential photosensitizer against bladder cancer.

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Section: Resultssupporting

confidence: 80%

Section: Resultsmentioning

confidence: 64%

Section: Resultsmentioning

confidence: 99%

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Modified Titanium Dioxide as a Potential Visible-Light-Activated Photosensitizer for Bladder Cancer Treatment

et al. 2022

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“…The surface of the Ti(OH) 4 was characterized by X-ray photoelectron spectroscopy (XPS), in which the XPS spectrum in the O1s region showed two peaks (Figure 1(a)). The main peak at 529.9 eV is related to the oxygen anions, O 2− , bound to the metal cations in the lattice, and the second peak at 532.9 eV could be attributed to the formation of peroxo groups on the Ti(OH) 4 [20]. Raman spectra of Ti(OH) 4 and calcined materials are reported in Figure 1(b).…”

Section: Characterizationmentioning

confidence: 99%

New Approach of the Oxidant Peroxo Method (OPM) Route to Obtain Ti(OH)₄ Nanoparticles with High Photocatalytic Activity under Visible Radiation

Nogueira

Ribeiro

Gorup

et al. 2018

International Journal of Photoenergy

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Environmental problems related to the generation of wastewater contaminated with organic compounds and the emissions of pollutants from fuel burning have become major global problems. Thus, there is a need for the development of alternative and economically viable technologies for the remediation of the affected ecosystems. Therefore, this work describes the preparation and characterization of a Ti(OH)4 catalyst with the modified surface for application in the photodegradation of organic compounds (methylene blue (MB) dye and the drug amiloride (AML)) and in the artificial photosynthesis process. Characterization results reveal that peroxo groups on the surface of the catalyst had a great influence on the optical properties of the Ti(OH)4 and consequently in its photocatalytic property. This catalyst showed a high photocatalytic activity for the degradation of organic pollutants under visible radiation, reaching approximately 98% removal of both the dye and the drug in 150 min of reaction. In addition, the catalyst presented a great potential for the reduction of CO2 under ultraviolet (UV) radiation when compared to P25, which is a classic catalyst used in photocatalytic processes. The highest photocatalytic activity can be attributed to the strong visible light absorption, due to the narrow band gap, and the effective separation of photogenerated electron-hole pairs caused by the peroxo groups on the Ti(OH)4 surface.

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“…Since XRD and FTIR depict no signicant dierence between the various precursors, it is expected that all of them will convert to phase pure BaSnO 3 on no such literature on Sn or its compounds. 40,54,55 This study highlights such eects of drying on phase evolution of BaSnO 3 .…”

Section: Eect Of Drying Conditions and Identication Of The Reaction Typementioning

confidence: 60%

Alcohol Assisted Solution-Combustion Technique for the Synthesis of Phase-Pure BaSnO3 Nanoparticles at 130 °C

Chawla

Aggarwal

Kumar

et al. 2021

Preprint

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Lowering the synthesis temperature to obtain phase pure BaSnO3, which is the host material for high figure-of-merit (FOM) perovskite transparent conductors (TCs), can expand the horizons for its optoelectronic applications, with an obvious reduction in the thermal budget. In this work, we have developed a novel solution combustion technique for the synthesis of BaSnO3 nanoparticles. A peroxo/superoxo precursor to the nanoparticles is first synthesized by co-precipitation of the tin and barium salts via the H2O2 assisted or the `CSMC' route. The phase evolution, under different drying conditions of the wet precursor to crystalline BaSnO3 nanoparticles is then studied. We find that the crystallization temperature of BaSnO3 is significantly reduced by adding an organic solvent such as ethanol or propanol to the precursor; temperatures as low as 130 °C yield phase pure BaSnO3 nanoparticles. We establish that the organic solvent increases the reactive O2 ligand content, which plays a pivotal role in the synthesis. Due to this, an exothermic reaction occurs around 130 °C, thereby providing the heat of reaction for conversion of the precursor to phase-pure BaSnO3. Importantly, this method should also allow for the facile incorporation of dopants, paving the way for synthesis of high FOM TCs at low temperatures. Such low synthesis temperatures enable BaSnO3 to be used in devices having temperature limitations during device processing, such as heterojunction Si solar cells or perovskite-based solar cells in an n-i-p architecture.

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Enhanced reactivity of peroxo-modified surface of titanium dioxide nanoparticles used to synthesize ultrafine bismuth titanate powders at lower temperatures

Cited by 13 publications

References 43 publications

Modified Titanium Dioxide as a Potential Visible-Light-Activated Photosensitizer for Bladder Cancer Treatment

Modified Titanium Dioxide as a Potential Visible-Light-Activated Photosensitizer for Bladder Cancer Treatment

New Approach of the Oxidant Peroxo Method (OPM) Route to Obtain Ti(OH)₄ Nanoparticles with High Photocatalytic Activity under Visible Radiation

Alcohol Assisted Solution-Combustion Technique for the Synthesis of Phase-Pure BaSnO3 Nanoparticles at 130 °C

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Enhanced reactivity of peroxo-modified surface of titanium dioxide nanoparticles used to synthesize ultrafine bismuth titanate powders at lower temperatures

Cited by 13 publications

References 43 publications

Modified Titanium Dioxide as a Potential Visible-Light-Activated Photosensitizer for Bladder Cancer Treatment

Modified Titanium Dioxide as a Potential Visible-Light-Activated Photosensitizer for Bladder Cancer Treatment

New Approach of the Oxidant Peroxo Method (OPM) Route to Obtain Ti(OH)4 Nanoparticles with High Photocatalytic Activity under Visible Radiation

Alcohol Assisted Solution-Combustion Technique for the Synthesis of Phase-Pure BaSnO3 Nanoparticles at 130 °C

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Product

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New Approach of the Oxidant Peroxo Method (OPM) Route to Obtain Ti(OH)₄ Nanoparticles with High Photocatalytic Activity under Visible Radiation