Visible light absorption of surface-modified Al2O3 powders: A comparative DFT and experimental study

Đorđević, Vesna; Sredojević, Dušan N.; Dostanić, Jasmina; Lončarević, Davor; Ahrenkiel, S. Phillip; Švrakić, N. M.; Brothers, Edward N.; Belić, Milivoj; Nedeljković, Jovan M.

doi:10.1016/j.micromeso.2018.06.053

Cited by 17 publications

(12 citation statements)

References 70 publications

(70 reference statements)

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“…[ 37,62 ] The adsorption event can be verified by observing increased light absorption and a redshifting in the UV–vis spectrum of the modified metal oxide particles. [ 19,33,38,63,64 ] Catecholates, such as dopamine, have also been reported to form polymers. [ 46,65 ] Catechol ligands can bind onto metal oxide surfaces through two adjacent phenolic –OH groups to form bonds based on bidentate chelating, bidentate inner sphere bridging or bidentate outer sphere bridging.…”

Section: Surface Adsorption Mechanismmentioning

confidence: 99%

“…The bidentate bonding mechanisms can have several variations, which are bidentate chelating, bidentate inner sphere bridging, or bidentate outer sphere bridging of a catechol group to the metal ions (Figure 2B). [ 19,64,68,72,73 ] Catechol‐type ligands are shown to form ordered densely packed monolayers on metal oxide surface, which give rise to additional electronic states above the VB level of metal oxide bandgap. [ 70,74,75 ] This results in the formation of CT complexes on the metal oxide surface that when photoexcited enable electron injection: direct electron transfer from the complex into the bulk metal oxide.…”

Section: Surface Adsorption Mechanismmentioning

confidence: 99%

“…This results in improved photoabsorption in the visible range and increased photocurrent density. [ 33,35,39,64,75,87,92 ] Other spectroscopic techniques used for the characterization of metal oxide/catechol systems include NMR spectroscopy for determining whether catechol‐type ligands link other molecules, [ 93 ] Raman spectroscopy for quantifying the amount of catechol ligand bonded to metal oxide nanostructure surface, [ 68,79 ] and photoemission spectroscopy for experimentally obtaining the occupied and unoccupied states of the adsorbed catechol ligands. [ 41 ] TGA studies allow for the calculation of the maximum grafting density of ligands, adsorption coefficient, and negative‐free binding energies of the surface functionalization of metal oxide nanostructures.…”

Section: Characterization Of Metal Oxide/catechol Systemsmentioning

confidence: 99%

“…[ 1,17,18 ] Similar to TiO 2 , ZnO is also limited by its wide bandgap and can have its photoabsorption enhanced by surface modification through catechol‐type ligands. [ 17,18 ] Catechol surface functionalization has also been explored for metal oxide semiconductors such as WO 3 , [ 21 ] SnO 2 , [ 22 ] Al 2 O 3 , [ 64 ] and BiOIO 3 . [ 19 ]…”

Section: Applicationsmentioning

confidence: 99%

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Surface Functionalization of Metal Oxide Semiconductors with Catechol Ligands for Enhancing Their Photoactivity

et al. 2021

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Metal oxide nanostructures are increasingly important materials for various emerging photocatalytic, photovoltaic and photoelectrochemical (PEC) applications. They are commonly used as photoelectrode materials due to their unique functional properties such as wide bandgap, reactive electronic transitions, and high stability. To increase the effectiveness of semiconductor metal oxides photoelectrodes, researchers seek to use various photoabsorption amplification and colloidal stability enhancement strategies. An effective method for achieving this is the surface functionalization of metal oxide semiconductors with catechol‐type ligands. Catechol‐type ligands are a family of organic molecules that adsorb very strongly onto metal oxides by forming complexes with metal atoms through adjacent phenolic —OH groups. Once adsorbed, catechol‐type ligands facilitate improved particle dispersion by inhibiting agglomeration and enhance photoexcitation in metal oxide semiconductors by improving visible light absorption. Herein, the surface complexation of catechol‐type ligand onto metal oxide semiconductor surfaces and their photoabsorption enhancement mechanisms is described. In addition, recent advances and trends in this area are described by presenting recent advancements made in applications of catechol‐modified metal oxide systems in photocatalysis, PEC biosensing, and solar cells.

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Section: Surface Adsorption Mechanismmentioning

confidence: 99%

Section: Surface Adsorption Mechanismmentioning

confidence: 99%

Section: Characterization Of Metal Oxide/catechol Systemsmentioning

confidence: 99%

Section: Applicationsmentioning

confidence: 99%

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Surface Functionalization of Metal Oxide Semiconductors with Catechol Ligands for Enhancing Their Photoactivity

et al. 2021

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“…α-Alumina (α-Al2O3) is one of the most widely used support materials for catalysts due to its high specific surface area, low cost, and favorable surface properties (Ðorđević et al, 2019, Goudarzi and Salavati-Niasari, 2018, Li et al, 2013. Thus, in terms of photocatalytic activity and stability, alumina was found to be a better support for α-Fe2O3 photocatalyst than silica (Li et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Preparation and Application of ZnFe2O4/α-Al2O3 for Photocatalytic Degradation of Methylene Blue Dye and Real Textile Effluent

Hamza

Umara

Hasan

2019

Aceh Int. J. Sci. Technol

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Present work was aimed at the development of α-Al2O3 supported ZnFe2O4 visible-light responsive photocatalysts. ZnFe2O4 and α-Al2O3 supported ZnFe2O4 were synthesized using coprecipitation method followed by calcination at 500 °C. The synthesized photocatalysts were characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM). The synthesized ZnFe2O4 has low crystallinity. The particle size of ZnFe2O4 is much smaller than that of the α-Al2O3 support, and ZnFe2O4 particles are dispersed on the surface of the crystalline α-Al2O3 support. 30 wt % ZnFe2O4/α-Al2O3 exhibited the highest photocatalytic activity for degradation of methylene blue dye than ZnFe2O4 and other α-Al2O3 supported photocatalysts containing 10 wt %, 20 wt % and 40 wt % ZnFe2O4. Kinetics of photocatalytic degradation of methylene blue dye using 30 wt % ZnFe2O4/Al2O3 obeys Langmuir-Hinshelwood kinetic model. Photocatalytic treatment of real textile wastewater resulted in more effective (when compared to photolytic treatment) in the reduction of wastewater's chemical oxygen demand (COD), pH, conductivity and total dissolved solids (TDS). 30 wt% ZnFe2O4/Al2O3 was found to be more effective than unsupported ZnFe2O4 for the reduction of wastewater's COD, pH, conductivity and TDS.

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Antimicrobial activity of silver nanoparticles supported by magnetite

et al. 2019

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Antibacterial and antifungal ability of silver nanoparticles (Ag NPs) supported by functionalized magnetite (Fe 3 O 4 ) with 5aminosalicylic acid (5-ASA) was tested against Gram-negative bacteria Escherichia coli, Gram-positive bacteria Staphylococcus aureus and yeast Candida albicans. Characterization of materials including transmission electron microscopy, X-ray diffraction analysis, and inductively coupled plasma optic emission spectroscopy technique followed each step during the course of nanocomposite preparation. The synthesized powder consists of 30-50 nm in size silver particles surrounded by clusters of smaller (∼ 10 nm) Fe 3 O 4 particles. The content of silver in the nanocomposite powder was found to be slightly above 40 wt.-%. Concentration-dependent and time-dependent bacterial reduction measurements in dark indicated that use of Ag NPs leads to the complete reduction of E. coli and S. aureus even at the concentration level of silver as low as 40 μg/mL. However, the negligible antifungal ability of synthesized nanocomposite was found against yeast C. albicans in the entire investigated concentration range (0.1-2.0 mg/mL of the nanocomposite, i. e., 40-800 μg/mL of silver). Complete inactivation of E. coli and S. aureus was achieved in five repeated cycles indicated that synthesized nanocomposite can perform under long-run working conditions. From the technological point of view, magnetic separation is the additional advantage of synthesized nanocomposite for potential use as an antibacterial agent.

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Visible light absorption of surface-modified Al2O3 powders: A comparative DFT and experimental study

Cited by 17 publications

References 70 publications

Surface Functionalization of Metal Oxide Semiconductors with Catechol Ligands for Enhancing Their Photoactivity

Surface Functionalization of Metal Oxide Semiconductors with Catechol Ligands for Enhancing Their Photoactivity

Preparation and Application of ZnFe2O4/α-Al2O3 for Photocatalytic Degradation of Methylene Blue Dye and Real Textile Effluent

Antimicrobial activity of silver nanoparticles supported by magnetite

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