Highly enhanced photocatalytic performance of TiO2 nanosheets through constructing TiO2/TiO2 quantum dots homojunction

Wang, Xing; Xia, Rui; Muhire, Elisée; Jiang, Subin; Huo, Xuejian; Gao, Meizhen

doi:10.1016/j.apsusc.2018.06.293

Cited by 71 publications

(33 citation statements)

References 56 publications

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“…As shown in Figure 4e, the O1s high-resolution XPS spectra of the sample can be deconvoluted into four peaks, with binding energies of 528.8, 529.8, 530.6, and 532.3 eV [46,47,48,49]. The peak at 528.8 eV can be ascribed to the lattice oxygen in NiO; the peak at 529.8 eV is identified as the Ni-O-Ti bond [33,50]; the peak at 530.6 eV can be ascribed to the defective oxygen in NiO and the crystal lattice oxygen in TiO 2 [51,52]; and the peak at 532.2 eV can be ascribed to the hydroxyl oxygen and water molecules on the surface of the mesoporous NiO. As shown in Figure 4f and Figure S5, for the TiO 2 QDs-NiO nanohybrids, the peak area ratio of the Ni-O-Ti bond first increased and then decreased with the increase of the TiO 2 QDs content, which is consistent with the change of the response value.…”

Section: Resultsmentioning

confidence: 99%

Effect of Heterointerface on NO2 Sensing Properties of In-Situ Formed TiO2 QDs-Decorated NiO Nanosheets

Zhang

Wang

et al. 2019

Nanomaterials

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In this work, TiO2 QDs-modified NiO nanosheets were employed to improve the room temperature NO2 sensing properties of NiO. The gas sensing studies showed that the response of nanocomposites with the optimal ratio to 60 ppm NO2 was nearly 10 times larger than that of bare NiO, exhibiting a potential application in gas sensing. Considering the commonly reported immature mechanism that the effective charge transfer between two phases contributes to an enhanced sensitivity, the QDs sensitization mechanism was further detailed by designing a series of contrast experiments. First, the important role of the QDs size effect was revealed by comparing the little enhanced sensitivity of TiO2 particle-modified NiO with the largely enhanced sensitivity of TiO2 QDs-NiO. Second, and more importantly, direct evidence of the heterointerface charge transfer efficiency was detailed by the extracted interface bond (Ti-O-Ni) using XPS peak fitting. This work can thus provide guidelines to design more QDs-modified nanocomposites with higher sensitivity for practical applications.

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Section: Resultsmentioning

confidence: 99%

Effect of Heterointerface on NO2 Sensing Properties of In-Situ Formed TiO2 QDs-Decorated NiO Nanosheets

Zhang

Wang

et al. 2019

Nanomaterials

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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%

“…As discussed previously, the titanium oxide photocatalyst proved to be efficient in the treatment of wastewater pollutants. The extended applicability of nano-TiO 2 as photocatalyst is limited due to the rapid recombination of electron-hole pair and a large band gap 44 . In the context of the efforts to overcome these drawbacks, the obtained quartz fibers decorated with TiO 2 presents a lower band gap, thus enhancing the photocatalytic activity.…”

Section: Uv-vis-drs Analysismentioning

confidence: 99%

“…This shift of the SiO 2 surface binding energy could be assigned to the lower binding energy of the Si placed at the interface during the TiO 2 grafting onto SiO 2 , and to the formation of Ti-O-Si bond replacing Si-O-Si bond. Although the binding energies for Ti2p peaks put in evidence that the titanium is in its Ti 4+ state, there is a shift towards lower binding energies from the characteristic value for Ti 4+ / TiO 2 bulk of 458.5 eV 47 to 458.0 eV for Ti2p 3/2 , while the peak for Ti2p 1/2 is placed at 463.4 eV 44,48 . Also, the O1s peak was shifted to lower values, with a maximum at 529.5 eV following an increased negative charge density at O level partially due to a higher degree of covalence of Si-O bond compared to the ionic character of Ti-O bond 48 .…”

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confidence: 98%

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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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“…Before decorating NGQDs, sample T2 and T3 exhibited nearly the same constant rate, higher than that of T0 and T1. RhB could be easily absorbed on the titania surface with reactive {001} facet exposure, leading to subsequent dye self-photosentization process decomposing RhB under visible light irradiation [51][52][53].…”

Section: Photocatalytic Performancementioning

confidence: 99%

Facet-Dependent Interfacial Charge Transfer in TiO2/Nitrogen-Doped Graphene Quantum Dots Heterojunctions for Visible-Light Driven Photocatalysis

Lyu

et al. 2019

Catalysts

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Interfacial charge transfer is crucial in the efficient conversion of solar energy into fuels and electricity. In this paper, heterojunction composites were fabricated, comprised of anatase TiO2 with different percentages of exposed {101} and {001} facets and nitrogen-doped quantum dots (NGQDs) to enhance the transfer efficiency of photo-excited charge carriers. The photocatalytic performances of all samples were evaluated for RhB degradation under visible light irradiation, and the hybrid containing TiO2 with 56% {001} facets demonstrated the best photocatalytic activity. The excellent photoactivity of TiO2/NGQDs was owed to the synergistic effects of the following factors: (i) The unique chemical features of NGQDs endowed NGQDs with high electronic conductivities and provided its direct contact with the TiO2 surface via forming Ti–O–C chemical bonds. (ii) The co-exposed {101} and {001} facets were beneficial for the separation and transfer of charge carriers in anatase TiO2. (iii) The donor-acceptor interaction between NGQDs and electron-rich {101} facets of TiO2 could remarkably enhance the photocurrent, thus hindering the charge carriers recombination rate. Extensive characterization of their physiochemical properties further showed the synergistic effect of facet-manipulated electron-hole separation in TiO2 and donor-acceptor interaction in graphene quantum dots (GQDs)/TiO2 on photocatalytic activity.

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Highly enhanced photocatalytic performance of TiO2 nanosheets through constructing TiO2/TiO2 quantum dots homojunction

Cited by 71 publications

References 56 publications

Effect of Heterointerface on NO2 Sensing Properties of In-Situ Formed TiO2 QDs-Decorated NiO Nanosheets

Effect of Heterointerface on NO2 Sensing Properties of In-Situ Formed TiO2 QDs-Decorated NiO Nanosheets

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

Facet-Dependent Interfacial Charge Transfer in TiO2/Nitrogen-Doped Graphene Quantum Dots Heterojunctions for Visible-Light Driven Photocatalysis

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