Tailoring the reducibility and catalytic activity of CuO nanoparticles for low temperature CO oxidation

Zedan, Abdallah F.; Mohamed, Assem T.; El‐Shall, M. Samy; AlQaradawi, Siham Y.; Aljaber, Amina S.

doi:10.1039/c8ra03623c

Cited by 75 publications

(39 citation statements)

References 64 publications

(71 reference statements)

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“…Copper oxide (CuO) has been considered to be one of the best semiconductor metal oxides as a result of its important chemical and physical properties such as large surface area, excellent solar light absorbance, and a narrow band gap (1.2 eV) [ 8 , 9 , 10 , 11 ]. CuO materials have a monoclinic structure and numerous attractive aspects, such as high stability, super thermal conductivity, photovoltaic properties, and antimicrobial activity.…”

Section: Introductionmentioning

confidence: 99%

Surface Study of CuO Nanopetals by Advanced Nanocharacterization Techniques with Enhanced Optical and Catalytic Properties

et al. 2020

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In the present work, a facile one-step hydrothermal synthesis of well-defined stabilized CuO nanopetals and its surface study by advanced nanocharacterization techniques for enhanced optical and catalytic properties has been investigated. Characterization by Transmission electron microscopy (TEM) analysis confirmed existence of high crystalline CuO nanopetals with average length and diameter of 1611.96 nm and 650.50 nm, respectively. The nanopetals are monodispersed with a large surface area, controlled morphology, and demonstrate the nanocrystalline nature with a monoclinic structure. The phase purity of the as-synthesized sample was confirmed by Raman spectroscopy and X-ray diffraction (XRD) patterns. A significantly wide absorption up to 800 nm and increased band gap were observed in CuO nanopetals. The valance band (VB) and conduction band (CB) positions at CuO surface are measured to be of +0.7 and −1.03 eV, respectively, using X-ray photoelectron spectroscopy (XPS), which would be very promising for efficient catalytic properties. Furthermore, the obtained CuO nanopetals in the presence of hydrogen peroxide ( H 2 O 2 ) achieved excellent catalytic activities for degradation of methylene blue (MB) under dark, with degradation rate > 99% after 90 min, which is significantly higher than reported in the literature. The enhanced catalytic activity was referred to the controlled morphology of monodispersed CuO nanopetals, co-operative role of H 2 O 2 and energy band structure. This work contributes to a new approach for extensive application opportunities in environmental improvement.

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Section: Introductionmentioning

confidence: 99%

Surface Study of CuO Nanopetals by Advanced Nanocharacterization Techniques with Enhanced Optical and Catalytic Properties

et al. 2020

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“…In addition, they have antimicrobial properties against a wide range of pathogenic microorganisms [ 9 ], but their use in medical applications has been questioned due to their high toxicity [ 10 , 11 ]. One of the main applications of nanoscale structures of copper and its oxides is heterogeneous catalysis systems, and these NSs perform more efficiently compared to bulk analogs [ 12 , 13 , 14 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

Cu/CuO Composite Track-Etched Membranes for Catalytic Decomposition of Nitrophenols and Removal of As(III)

et al. 2020

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One of the promising applications of nanomaterials is to use them as catalysts and sorbents to remove toxic pollutants such as nitroaromatic compounds and heavy metal ions for environmental protection. This work reports the synthesis of Cu/CuO-deposited composite track-etched membranes through low-temperature annealing and their application in catalysis and sorption. The synthesized Cu/CuO/poly(ethylene terephthalate) (PET) composites presented efficient catalytic activity with high conversion yield in the reduction of nitro aryl compounds to their corresponding amino derivatives. It has been found that increasing the time of annealing raises the ratio of the copper(II) oxide (CuO) tenorite phase in the structure, which leads to a significant increase in the catalytic activity of the composites. The samples presented maximum catalytic activity after 5 h of annealing, where the ratio of CuO phase and the degree of crystallinity were 64.3% and 62.7%, respectively. The catalytic activity of pristine and annealed composites was tested in the reduction of 4-nitroaniline and was shown to remain practically unchanged for five consecutive test cycles. Composites annealed at 140 °C were also tested for their capacity to absorb arsenic(III) ions in cross-flow mode. It was observed that the sorption capacity of composite membranes increased by 48.7% compared to the pristine sample and reached its maximum after 10 h of annealing, then gradually decreased by 24% with further annealing.

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“…Typically, the Cu nanoparticles used experimentally have an average diameter of B30 nm for catalytic CO oxidation, 19 while they are in the range of 15-35 nm for copper oxide catalysts. 24,25 A smaller copper oxide catalyst with a particle size of 3.6 nm was obtained by specific preparation methods, 26 and it displays an enhanced catalytic activity. Moreover, previous studies have revealed that the CO oxidation conversion rate is considerably affected by the crystal size of the catalyst where it generally increases up to an optimal crystal size, after which the conversion rate decreases again.…”

Section: Introductionmentioning

confidence: 99%

Varying oxygen coverage on Cu₅₅ and its effect on CO oxidation

Akola

2019

Phys. Chem. Chem. Phys.

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Adsorption of molecular oxygen on a Cu 55 cluster and the resulting oxidation effects have been investigated by spin-polarized density functional theory (DFT). The optimal structure for each Cu 55 O 2N (N = 1-20) complex has been obtained via a sequential addition of O 2 and systematic screening of the preferable adsorption sites. Upon structural optimization, several O 2 molecules dissociate readily on Cu 55 at different oxygen coverages, and further DFT molecular dynamics simulations at 300 K confirm the instability (small dissociation barrier) of the remaining O 2 and a spontaneous movement of some oxygen atoms from the surface sites towards the cluster interior. The Cu 55 cluster and its oxidized derivatives have been placed on a g-Al 2 O 3 (100) surface to study the cluster-support interaction, and furthermore, CO oxidation reactions on both Cu 55 (O) 2N and Cu 55 (O) 2N /g-Al 2 O 3 (100) have been studied as a function of oxygen coverage. The CO oxidation reaction barrier is rather insensitive to the oxygen coverage regardless of the support, indicating a small increase in activity with the number of surface oxygen atoms.

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Tailoring the reducibility and catalytic activity of CuO nanoparticles for low temperature CO oxidation

Abstract: . Furthermore, the tailored catalysts exhibited excellent long-term stability for CO oxidation for up to 48 h on stream. These readily-reducible CuO nanoparticles could serve as efficient, inexpensive and durable catalysts for CO oxidation at low temperatures.

Cited by 75 publications

References 64 publications

Surface Study of CuO Nanopetals by Advanced Nanocharacterization Techniques with Enhanced Optical and Catalytic Properties

Surface Study of CuO Nanopetals by Advanced Nanocharacterization Techniques with Enhanced Optical and Catalytic Properties

Cu/CuO Composite Track-Etched Membranes for Catalytic Decomposition of Nitrophenols and Removal of As(III)

Varying oxygen coverage on Cu₅₅ and its effect on CO oxidation

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Tailoring the reducibility and catalytic activity of CuO nanoparticles for low temperature CO oxidation

Abstract: . Furthermore, the tailored catalysts exhibited excellent long-term stability for CO oxidation for up to 48 h on stream. These readily-reducible CuO nanoparticles could serve as efficient, inexpensive and durable catalysts for CO oxidation at low temperatures.

Cited by 75 publications

References 64 publications

Surface Study of CuO Nanopetals by Advanced Nanocharacterization Techniques with Enhanced Optical and Catalytic Properties

Surface Study of CuO Nanopetals by Advanced Nanocharacterization Techniques with Enhanced Optical and Catalytic Properties

Cu/CuO Composite Track-Etched Membranes for Catalytic Decomposition of Nitrophenols and Removal of As(III)

Varying oxygen coverage on Cu55 and its effect on CO oxidation

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Varying oxygen coverage on Cu₅₅ and its effect on CO oxidation