Easy stabilization of Evonik Aeroxide P25 colloidal suspension by 4-hydroxybenzoic acid functionalization

Mahy, Julien G.; Douven, Sigrid; Hollevoet, Jonas; Body, Nathalie; Haynes, Tommy; Hermans, Sophie; Lambert, Stéphanie; Páez, Carlos A.

doi:10.1016/j.surfin.2021.101501

Cited by 2 publications

(2 citation statements)

References 45 publications

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“…The bulky yellowish residue was dried at 80 • C for 12 h. After drying, the solid was ground in the agate mortar to obtain PHBA-P25 as a yellow powder. This protocol is a modified version of the protocol from Mahy et al [60].…”

Section: Physicochemical Properties 411 Preparation Of Phba-p25 Mater...mentioning

confidence: 99%

“…In addition, the effect of 4-hydroxybenzoic acid (PHBA) as a linker to increase the amount of attached porphyrin to the TiO 2 surface was also studied. Introducing PHBA on the P25 surface could potentially lead to increased stability of the resulting composite, thus increasing photocatalytic activity [60]. Moreover, the presence of palladium ions in porphyrin-based materials resulted in increased photoinduced charge separation compared to metal-free or zinc derivatives [61,62].…”

Section: Introductionmentioning

confidence: 99%

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Enhancing Visible-Light Photocatalysis with Pd(II) Porphyrin-Based TiO2 Hybrid Nanomaterials: Preparation, Characterization, ROS Generation, and Photocatalytic Activity

Malec,

Warszyńska,

Repetowski

et al. 2023

Molecules

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Novel hybrid TiO2-based materials were obtained by adsorption of two different porphyrins on the surface of nanoparticles—commercially available 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) and properly modified metalloporphyrin—5,10,15,20-tetrakis(2,6-difluoro-3-sulfophenyl)porphyrin palladium(II) (PdF2POH). The immobilization of porphyrins on the surface of TiO2 was possible due to the presence of sulfonyl groups. To further elevate the adsorption of porphyrin, an anchoring linker—4-hydroxybenzoic acid (PHBA)—was used. The synthesis of hybrid materials was proven by electronic absorption spectroscopy, dynamic light scattering (DLS), and photoelectrochemistry. Results prove the successful photosensitization of TiO2 to visible light by both porphyrins. However, the presence of the palladium ion in the modifier structure played a key role in strong adsorption, enhanced charge separation, and thus effective photosensitization. The incorporation of halogenated metalloporphyrins into TiO2 facilitates the enhancement of the comprehensive characteristics of the investigated materials and enables the evaluation of their performance under visible light. The effectiveness of reactive oxygen species (ROS) generation was also determined. Porphyrin-based materials with the addition of PHBA seemed to generate ROS more effectively than other composites. Interestingly, modifications influenced the generation of singlet oxygen for TPPS but not hydroxyl radical, in contrast to PdF2POH, where singlet oxygen generation was not influenced but hydroxyl radical generation was increased. Palladium (II) porphyrin-modified materials were characterized by higher photostability than TPPS-based nanostructures, as TPPS@PHBA-P25 materials showed the highest singlet oxygen generation and may be oxidized during light exposure. Photocatalytic activity tests with two model pollutants—methylene blue (MB) and the opioid drug tramadol (TRML)—confirmed the light dose-dependent degradation of those two compounds, especially PdF2POH@P25, which led to the virtually complete degradation of MB.

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Section: Physicochemical Properties 411 Preparation Of Phba-p25 Mater...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Enhancing Visible-Light Photocatalysis with Pd(II) Porphyrin-Based TiO2 Hybrid Nanomaterials: Preparation, Characterization, ROS Generation, and Photocatalytic Activity

Malec,

Warszyńska,

Repetowski

et al. 2023

Molecules

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Evonik P25 photoactivation in the visible range by surface grafting of modified porphyrins for p-nitrophenol elimination in water

2023

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<abstract> An Evonik P25 TiO2 material is modified using a porphyrin containing Si-(OR)3 extremities to extend its absorption spectrum in the visible range. Two different loadings of porphyrin are grafted at the surface of P25. The results show that the crystallinity and the texture of the P25 are not modified with the porphyrin grafting and the presence of the latter is confirmed by Fourier-transform infrared spectroscopy (FTIR) measurements. All three samples are composed of anatase/rutile titania nanoparticles around 20 nm in size with a spherical shape. The absorption spectra of the porphyrin modified samples show visible absorption alongside the characteristic Soret and Q bands of porphyrin, despite slightly shifted peak values. The 29Si solid state nuclear magnetic resonance (NMR) spectra show that the porphyrin is linked with Ti–O–C and Ti–O–Si bonds with the Evonik P25, allowing for a direct electron transfer between the two materials. Finally, the photoactivity of the materials is assessed on the degradation of a model pollutant—<italic>p</italic>-nitrophenol (PNP)—in water. The degradation is substantially enhanced when the porphyrin is grafted at its surface, whereas a very low activity is evidenced for P25. Indeed, with the best sample, the activity increases from 9% to 38% under visible light illumination. This improvement is due to the activation of the porphyrin under visible light that produces electrons, which are then transferred to the TiO2 to generate radicals able to degrade organic pollutants. The observed degradation is confirmed to be a mineralization of the PNP. Recycling experiments show a constant PNP degradation after 5 cycles of photocatalysis of 24 h each. </abstract>

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Easy stabilization of Evonik Aeroxide P25 colloidal suspension by 4-hydroxybenzoic acid functionalization

Cited by 2 publications

References 45 publications

Enhancing Visible-Light Photocatalysis with Pd(II) Porphyrin-Based TiO2 Hybrid Nanomaterials: Preparation, Characterization, ROS Generation, and Photocatalytic Activity

Enhancing Visible-Light Photocatalysis with Pd(II) Porphyrin-Based TiO2 Hybrid Nanomaterials: Preparation, Characterization, ROS Generation, and Photocatalytic Activity

Evonik P25 photoactivation in the visible range by surface grafting of modified porphyrins for p-nitrophenol elimination in water

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