The effect of heat treatment on the anatase–rutile phase transformation and photocatalytic activity of Sn-doped TiO<sub>2</sub> nanomaterials

Zhu, Xiaodong; Han, Shihu; Feng, Wei; Kong, Qingquan; Dong, Zhihong; Wang, Chenxi; Jiahao, Lei; Qian, Yi

doi:10.1039/c8ra00766g

Cited by 45 publications

(22 citation statements)

References 43 publications

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“…For a higher coverage of 0.05 ML Sn, peaks for both metallic Sn at 484.8 eV and SnO x at 487.3 eV are observed with roughly equal intensities. The 484.8 eV binding energy is in agreement with the 484.5–485.2 eV values reported for metallic Sn. ,− The value of 487.3 eV is higher than the ∼486.0–486.6 eV ,,, assigned to Sn 4+ in bulk SnO 2 , but clusters ,,,, and thin films , generally have higher binding energies than bulk SnO 2 and have been observed at ∼487 eV. Given the similarities between the Sn 2+ and Sn 4+ binding energies in oxides, especially in cases where the structure of SnO x is not well-defined, it is difficult to distinguish between SnO 2 and SnO. ,,,− Due to the small signals that we observe for the low Sn coverages, the use of the Auger parameter , is also not a reliable method of distinction between SnO and SnO 2 .…”

Section: Resultssupporting

confidence: 82%

“…Sn 4+ can be easily substituted for Ti 4+ in rutile TiO 2 , and the resulting materials are believed to possess superior chemical, optical, and electronic properties. − For applications involving solar cells, doping TiO 2 with Sn 4+ improves performance by decreasing the band gap . Sn-doped TiO 2 also exhibits excellent photocatalytic activity for reactions such as photodegradation of dyes , and photo-oxidation of NO x 19 and organics; this improved photoactivity is attributed to a decrease in the rate of electron–hole recombination and improved light absorption after Sn 4+ doping. , For TiO 2 used in the anodes of Li-ion batteries, better power, capacity, and stability are reported after Sn doping. , …”

Section: Introductionmentioning

confidence: 99%

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Oxidation of Sn at the Cluster–Support Interface: Sn and Pt–Sn Clusters on TiO₂(110)

et al. 2021

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The growth of Sn and Pt–Sn clusters on TiO2(110) has been studied by scanning tunneling microscopy, X-ray photoelectron spectroscopy (XPS), low energy ion scattering (LEIS), and density functional theory (DFT). At low Sn coverages (0.02 ML), single-layer high clusters of SnO x are formed with a narrow size distribution and uniform spatial distribution. XPS experiments indicate that these clusters consist of oxidized Sn, and the corresponding reduction in the TiO2 substrate is observed. At higher Sn coverages, the surface is still dominated by two-dimensional clusters of SnO x , but larger three-dimensional clusters of metallic Sn also appear. As the Sn coverage is increased, the number of three-dimensional clusters increases, and the ratio of Sn/SnO x increases, suggesting that SnO x and reduced TiO x form at the cluster–support interface. When Pt is deposited on top of the Sn/SnO x clusters, the relatively mobile Pt atoms diffuse across the TiO2 surface and become incorporated into existing Sn/SnO x clusters. Furthermore, the addition of Pt to the Sn/SnO x clusters causes the reduction of SnO x to metallic Sn and the oxidation of Ti3+ to Ti4+; this behavior is attributed to the formation of Pt–Sn alloy clusters, which results in the diffusion of Sn away from the interface with the TiO2 support. In contrast, when Sn is deposited on an equal coverage of Pt clusters, new Sn/SnO x clusters are formed that coexist with Pt–Sn clusters. However, the surfaces of both Pt on Sn and Sn on Pt clusters are Sn-rich due to the lower surface free energy of Sn compared to Pt. DFT calculations demonstrate that M–TiO2 bonding is favored over M–M bonding for M = Sn, unlike for transition metals such as M = Pt, Au, Ni, and Co. Furthermore, the substantial charge transfer from Sn to TiO2 leads to dipole–dipole repulsion of Sn atoms that prevents agglomeration into the larger clusters that are observed for the mid-late transition metals. DFT studies also confirm that the addition of Pt to a Sn cluster results in strong Pt–Sn bond formation and diminished Sn–O interactions.

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Section: Resultssupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Oxidation of Sn at the Cluster–Support Interface: Sn and Pt–Sn Clusters on TiO₂(110)

et al. 2021

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“…The results of DRS analysis for silica microfibers grafted with nanotitania highlighted a band gap of 3.37 eV. Such band gap values could be associated with the crystalline characteristics of the material 44,45 (2020) 10:136 | https://doi.org/10.1038/s41598-019-56836-7…”

Section: Uv-vis-drs Analysismentioning

confidence: 98%

Added value recyclability of glass fiber waste as photo-oxidation catalyst for toxic cytostatic micropollutants

Nechifor

Totu

Nechifor

et al. 2020

Sci Rep

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There is an increased interest in recycling valuable waste materials for usage in procedures with high added values. Silica microparticles are involved in the processes of catalysis, separation, immobilization of complexants, biologically active compounds, and different nanospecies, responding to restrictive requirements for selectivity of various chemical and biochemical processes. This paper presents the surface modification of accessible and dimensionally controlled recycled silica microfiber with titanium dioxide. Strong base species in organic solvents: methoxide, ethoxide, propoxide, and potassium butoxide in corresponding alcohol, activated the glass microfibres with 12-13 µm diameter. In the photo-oxidation process of a toxic micro-pollutant, cyclophosphamide, the new composite material successfully proved photocatalytic effectiveness. The present work fulfills simultaneously two specific objectives related to the efforts directed towards a sustainable environment and circular economy: recycling of optical glass microfibers resulted as waste from the industry, and their usage for the photooxidation of highly toxic emerging micro-pollutants. Inorganic-inorganic oxide-type composite materials offer the most interesting technical solutions in many physicochemical processes of bio-degradation, coating, separation, or catalysis 1,2. A particular case is presented by the silicon dioxide-titanium dioxide (TiO 2-SiO 2) composites that combine the distinctive characteristics of the two oxides. Thus, silicon dioxide is a technically-economically accessible material and can be made in the form of spherical particles 3 , nanofibers 4 , nanotubes 5 , or films 6 , thus being used as an active material, adsorbent or support for other materials with higher selectivity 7. Titanium dioxide prepared in predetermined forms: spheres 8 , nanotubes 9 , nano-threads 10 , or films 11 could be used as an adsorbent or covering, but especially like catalytic material 12. Of course, the combination of the two oxides' properties has been used for the most advanced applications: photocatalytic degradation of organic/pharmaceutical pollutants 13 , fuel cells 14 , membrane reactors 15 , bioreactors 16 , advanced separations 17 and clinical devices 18. Environmental researches proved that the widely used cytostatic drug, N, N-bis(2-chloroethyl)-1,3,2-oxazaphosphinan-2-amine 2-oxide known as cyclophosphamide, which is a cyclic amide, produces residues with mutagenic action. Although mainly known as an anticancer drug, cyclophosphamide is also administrated frequently as an anti-inflammatory or immunolytic agent for rheumatoid arthritis 19 , or nephrotic syndrome 20 , systemic lupus erythematosus 21 , or systemic sclerosis lung fibrosis 22. This important cytostatic compound administrated for autoimmune diseases, and cancer chemotherapy, as well as its metabolites, are released into effluents that reach surface and ground waters 23. The cyclophosphamide action through nucleophilic compounds' alkylation and metabolic activation result in dra...

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“…The broad exothermic peak is observed at a temperature range of 200 to 500 with less intensity, which may reflect the combustion of residual organic matter (auto-ignition temp. of EAcAc = 295°C), also, the crystallization of the anatase and rutile phases in the particles, and the phase transformation of the anatase to the rutile phase [17]. According to the DTA analysis results, temperatures of 350, 450, 550, and 650°C were selected as the sample calcination temperature.…”

Section: Tg-dta Analysismentioning

confidence: 99%

Structural, photocatalytic and surface analysis of Nb/Ag codoped TiO2 mesoporous nanoparticles

Gorgani

Kaleji

2020

J Sol-Gel Sci Technol

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In this study, several TiO2 mesoporous nanoparticles with different mol% of niobium and silver were synthesized using the sol–gel method. The crystalline phase, chemical state, photocatalytic and optical properties, specific surface area, and morphology of mesoporous nanoparticles were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–Vis reflective spectroscopy (UV–Vis), Brunauer–Emmett–Teller-specific surface area (BET) and field emission scanning electron microscopy (FESEM). With increasing calcination temperature, the photocatalytic activity of the samples gradually increased due to the improvement of crystallization of the anatase and rutile phases. Nb/Ag codoping sample calcined at 550 °C has reduced the band gap energy (3.17 eV to 3.06 eV) and improved the photocatalytic properties of samples under visible light (xenon lamp, 200 W for 1 h and 2 h). Doped TiO2 mesoporous nanoparticles were shown to have the highest photocatalytic activity as compared with the pure TiO2 nanoparticles. The best photocatalytic efficiency of codoped TiO2 mesoporous nanoparticles was observed for the TNA3 sample calcined under 550 °C, containing molar contents of Nb (0.5 mol%) and Ag (1 mol%) dopant ions with 95.60% efficiency.

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The effect of heat treatment on the anatase–rutile phase transformation and photocatalytic activity of Sn-doped TiO₂ nanomaterials

Abstract: Sn incorporation into TiO2 lattices promotes anatase/rutile transformation and Sn–TiO2 exhibits better photocatalytic activity at different temperatures.

Cited by 45 publications

References 43 publications

Oxidation of Sn at the Cluster–Support Interface: Sn and Pt–Sn Clusters on TiO₂(110)

Oxidation of Sn at the Cluster–Support Interface: Sn and Pt–Sn Clusters on TiO₂(110)

Added value recyclability of glass fiber waste as photo-oxidation catalyst for toxic cytostatic micropollutants

Structural, photocatalytic and surface analysis of Nb/Ag codoped TiO2 mesoporous nanoparticles

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The effect of heat treatment on the anatase–rutile phase transformation and photocatalytic activity of Sn-doped TiO2 nanomaterials

Abstract: Sn incorporation into TiO2 lattices promotes anatase/rutile transformation and Sn–TiO2 exhibits better photocatalytic activity at different temperatures.

Cited by 45 publications

References 43 publications

Oxidation of Sn at the Cluster–Support Interface: Sn and Pt–Sn Clusters on TiO2(110)

Oxidation of Sn at the Cluster–Support Interface: Sn and Pt–Sn Clusters on TiO2(110)

Added value recyclability of glass fiber waste as photo-oxidation catalyst for toxic cytostatic micropollutants

Structural, photocatalytic and surface analysis of Nb/Ag codoped TiO2 mesoporous nanoparticles

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Product

Resources

About

The effect of heat treatment on the anatase–rutile phase transformation and photocatalytic activity of Sn-doped TiO₂ nanomaterials

Oxidation of Sn at the Cluster–Support Interface: Sn and Pt–Sn Clusters on TiO₂(110)

Oxidation of Sn at the Cluster–Support Interface: Sn and Pt–Sn Clusters on TiO₂(110)