Photocatalytic Performance of Highly Active Brookite in the Degradation of Hazardous Organic Compounds Compared to Anatase and Rutile

Tran, Huyen T. T.; Kosslick, H.; Ibad, Muhammad Farooq; Fischer, Christine; Bentrup, Ursula; Vuong, Thanh Huyen; Nguyen, Long H.; Schulz, Axel

doi:10.1016/j.apcatb.2016.07.017

Cited by 80 publications

(38 citation statements)

References 89 publications

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“…Figure 1 shows the x-ray diffraction patterns of a) TiO 2 , b) TiO 2 /Graphene and c) Graphene samples heated at different temperatures. It can be seen in figure 1(a) that the TiO 2 anatase phase together with a small fraction of brookite phase [14] (peak centered at 30.8°corresponding to (121) plane and marked with a star) were obtained from the HT process; the phases percentages were found to be 94% anatase and 6% brookite. Brookite phase percentage was estimated by the methodology used in [15] and [16] 1(c)), which means that graphene layers stack together due to the increasing temperature.…”

Section: Methodsmentioning

confidence: 99%

UV and Visible light photodegradation of methylene blue with graphene decorated titanium dioxide

Acosta-Esparza

Rivera

Pérez-Centeno

et al. 2020

Mater. Res. Express

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Photocatalytic degradation of methylene blue by graphene decorated titanium dioxide (TiO 2 ) powders heated at different temperatures was analyzed. The powders were prepared by mixing TiO 2 with graphene prepared by the modified Hummers method. A thermal treatment was applied to mixed and pure TiO 2 powders with the aim of analyze their structural dependence on temperature, and consistently their photocatalytic degradation effect on methylene blue solutions exposed to UV and visible radiation. Structural characterization of the powders was carried out by x-ray diffraction and Raman spectroscopy. When irradiated with UV, the mixed powders showed as high as 87% photocatalytic degradation, while the pure TiO 2 reached values of 59%. For visible radiation, as it is expected, the pure TiO 2 showed no activity, while the mixture presented degradation of 40%.

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Section: Methodsmentioning

confidence: 99%

UV and Visible light photodegradation of methylene blue with graphene decorated titanium dioxide

Acosta-Esparza

Rivera

Pérez-Centeno

et al. 2020

Mater. Res. Express

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“…For comparison, P25 was also analyzed ( Figure 2d) and found to consist of 80% anatase and 20% rutile, in agreement with other reports [15]. Despite the inclusion of a third component in the deconvolution analysis, the Raman-derived percentage compositions are in good overall agreement with the respective XRD data as presented in Table 1. assigned to the B1g, A1g or B1g and Eg Raman vibration modes of the anatase phase, respectively [34,35]; the 410, 585, 637 and 685 cm −1 Raman peaks to A1g, B2g and A1g modes of the brookite phase; while the 445 and 610 cm −1 to the A1g and B1g modes of the rutile phase [4,9,24,36]. After spectral deconvolution, we were able to compare the intensity of the major peaks for each phase.…”

Section: Nanostructural Propertiesmentioning

confidence: 99%

“…Odling et al mention the significant difference between surface bound radicals (OH s • ) and free in solution radicals (OH f • ) on the degradation reactions [8]. TiO 2 photocatalytic activity depends on the crystal structure, phase composition, nanoparticle size distribution, porosity, band gap and surface-bound hydroxyl species [9]. TiO 2 exists mainly in three pure phases: anatase (A), brookite (B) and rutile (R).…”

Section: Introductionmentioning

confidence: 99%

“…Until very recently, most studies on the photocatalytic performance of nanoTiO 2 were conducted with anatase (A), as it has longer charge-carrier lifetime and mobility [8], while photocatalytic applications of brookite (B) and rutile (R) are the least known [9,[18][19][20]. Nowadays, a lot of attention is given to mixed phase TiO 2 photocatalysts as the synergistic effect between the two phases reduces the recombination effect [4].…”

Section: Introductionmentioning

confidence: 99%

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Tunable Composition Aqueous-Synthesized Mixed-Phase TiO2 Nanocrystals for Photo-Assisted Water Decontamination: Comparison of Anatase, Brookite and Rutile Photocatalysts

et al. 2020

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Mixed-phase nanoTiO 2 materials attract a lot of attention as advanced photocatalysts for water decontamination due to their intrinsic structure that allows better photo-excited e − cb -h + vb charge separation, hence improved photocatalytic efficiency. Currently, the best-known mixed-phase TiO 2 photocatalyst is P25 with approximate composition 80% Anatase/20% Rutile (A /r ). Apart from Anatase (A) and Rutile (R) phases, there is Brookite (B) which has been evaluated less as photocatalyst in mixed-phase nanoTiO 2 systems. In this work we present a sustainable solution process to synthesize tunable composition mixed-phase nanotitania photocatalysts in a continuously stirred tank reactor (CSTR) by modulating conditions like pH, C TiCl4 and time. In particular three mixed-phase TiO 2 nanomaterials were produced, namely one predominantly anatase with brookite as minor component (A /b ), one predominantly brookite with minor component rutile (B /r ), and one predominantly rutile with minor component brookite (R /b ) and evaluated as photocatalysts in the degradation of methyl orange. The three semiconducting nanomaterials were characterized by XRD and Raman spectroscopy to quantify the phase ratios and subjected to nano-morphological characterization by FE-SEM and TEM/HR-TEM. The new mixed-phase nanoTiO 2 materials are shown to be endowed with large specific surface area, ranging from 90-125 m 2 g −1 , double of that of P25, to be mesoporous and be surface-rich in Ti-OH molecular groups varying from 12%-20% versus 4% for P25. These properties though impact the adsorptive capacity with R /b and B /r removing > 50% of MO but not photocatalytic activity. The latter depends on nanograined mixed-phase structure and not mere assembly of different phase nanoparticles. First-order rate constants reveal essentially equivalent photocatalytic activity for anatase nanocrystals with either rutile (P25) or brookite (this work) domains.

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“…Thus, the electrons and holes will migrate faster from the bulk to the surface, which results in a low recombination rate [19]. The synthesis of pure brookite is technically difficult [20] so that only rare literature on the photocatalytic activity of brookite can be found [21][22][23][24]. In these studies brookite exhibits a higher photocatalytic activity because electrons are trapped, thus both electrons and holes are still accessible for reduction and oxidation reactions.…”

mentioning

confidence: 99%

Synthesis of High Crystalline TiO2 Nanoparticles on a Polymer Membrane to Degrade Pollutants from Water

et al. 2018

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Titanium dioxide (TiO 2 ) is described as an established material to remove pollutants from water. However, TiO 2 is still not applied on a large scale due to issues concerning, for example, the form of use or low photocatalytic activity. We present an easily upscalable method to synthesize high active TiO 2 nanoparticles on a polyethersulfone microfiltration membrane to remove pollutants in a continuous way. For this purpose, titanium(IV) isopropoxide was mixed with water and hydrochloric acid and treated up to 210 • C. After cooling, the membrane was simply dip-coated into the TiO 2 nanoparticle dispersion. Standard characterization was undertaken (i.e., X-ray powder diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, water permeance, contact angle). Degradation of carbamazepine and methylene blue was executed. By increasing synthesis temperature crystallinity and photocatalytic activity elevates. Both ultrasound modification of nanoparticles and membrane pre-modification with carboxyl groups led to fine distribution of nanoparticles. The ultrasound-treated nanoparticles gave the highest photocatalytic activity in degrading carbamazepine and showed no decrease in degradation after nine times of repetition. The TiO 2 nanoparticles were strongly bound to the membrane. Photocatalytic TiO 2 nanoparticles with high activity were synthesized. The innovative method enables a fast and easy nanoparticle production, which could enable the use in large-scale water cleaning.Catalysts 2018, 8, 376 2 of 16 efficiently from water. The main challenge is to generate a low cost, long-term stable, and reusable system with a high activity to degrade organic contaminants.The mode of application of TiO 2 is a crucial parameter as it already defines the degradation rate and success. Theoretically, the photocatalytic activity is the highest when using TiO 2 as nanoparticles in a suspension as the overall surface area can be immense. However, nanoparticles tend to agglomerate to larger particles (i.e., surface area is diminished) and after final cleaning the nanoparticles have to be removed extensively [9,10]. Binding TiO 2 to a support (e.g., membrane [11][12][13][14]) decreases the overall surface area but the degradation of pollutants can be executed in one step. Designing a porous support can overcome the surface area issues of a supported system. Membranes are ideal support systems as they are highly porous and can be produced easily, are cost effective, and exist in many different forms according to the need of the consumer. The pollutant is directly transported through the membrane to the photocatalyst for degradation. Slow transport of the pollutant to the photocatalyst (e.g., diffusion) is avoided. To generate a high surface area compound, the porosity should be high and the pore size low. Nonetheless, decreasing the pore size will increase the energy needed to operate the membrane system. Microfiltration membranes with a pore size of 0.22 and 0.45 µm have been successfully utilized [13,14].Other param...

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Photocatalytic Performance of Highly Active Brookite in the Degradation of Hazardous Organic Compounds Compared to Anatase and Rutile

Cited by 80 publications

References 89 publications

UV and Visible light photodegradation of methylene blue with graphene decorated titanium dioxide

UV and Visible light photodegradation of methylene blue with graphene decorated titanium dioxide

Tunable Composition Aqueous-Synthesized Mixed-Phase TiO2 Nanocrystals for Photo-Assisted Water Decontamination: Comparison of Anatase, Brookite and Rutile Photocatalysts

Synthesis of High Crystalline TiO2 Nanoparticles on a Polymer Membrane to Degrade Pollutants from Water

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