Gold and iron oxide hybrid nanocomposite materials

Leung, Ken Cham‐Fai; Xuan, Shouhu; Zhu, Xiaoming; Wang, Dawei; Chak, Chun‐Pong; Lee, Siu‐Fung; Ho, Watson K.‐W.; Chung, Berton C.‐T.

doi:10.1039/c1cs15213k

Cited by 249 publications

(175 citation statements)

References 119 publications

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“…2C). The CSs were subjected to the twostep ligand exchange to cap the Au and Fe 3 O 4 patches with thiolterminated PS and dopamine-terminated polyethylene glycol molecules, respectively (2,23,24). The number average molecular weight of the PS ligands was 5,000 g/mol, similar to that used for end functionalization of the NRs, and the molecular weight of dopamine-terminated polyethylene glycol ligands was 1,200 g/ mol.…”

Section: Resultsmentioning

confidence: 99%

Colloidal analogs of molecular chain stoppers

Klinkova

Thérien-Aubin

Choueiri

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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A similarity between chemical reactions and self-assembly of nanoparticles offers a strategy that can enrich both the synthetic chemistry and the nanoscience fields. Synthetic methods should enable quantitative control of the structural characteristics of nanoparticle ensembles such as their aggregation number or directionality, whereas the capability to visualize and analyze emerging nanostructures using characterization tools can provide insight into intelligent molecular design and mechanisms of chemical reactions. We explored this twofold concept for an exemplary system including the polymerization of bifunctional nanoparticles in the presence of monofunctional colloidal chain stoppers. Using reaction-specific design rules, we synthesized chain stoppers with controlled reactivity and achieved quantitative fine-tuning of the selfassembled structures. Analysis of the nanostructures provided information about polymerization kinetics, side reactions, and the distribution of all of the species in the reaction system. A quantitative model was developed to account for the reactivity, kinetics, and side reactions of nanoparticles, all governed by the design of colloidal chain stoppers. This work provided the ability to test theoretical models developed for molecular polymerization.nanopolymer | plasmonic properties T he similarity between chemical reactions and colloidal selfassembly forms a bridge between molecular and colloidal length scales, spanning over several orders of magnitude (1-3). It is currently well-established that a broad range of particles with two reactive patches, such as polymer microbeads (4), inorganic nanoparticles (5), and block copolymer micelles (6), act similar to bifunctional molecular monomers and organize themselves into one-dimensional polymer-like structures. The self-assembly of colloidal polymers can also be assisted by the application of an electric (7) or magnetic field (8). The analogy between chemical reactions and the self-assembly process offers a mutually beneficial approach: (i) the use of synthetic concepts as a strategy for controllable and quantitative self-assembly of colloidal particles into structures with well-defined sizes, spatial organization, and directionality and (ii) the development of fundamental knowledge about chemical reactions by visualizing colloidal assemblies.The replication of synthetic concepts developed at the molecular scale--beyond qualitative prediction of a particular structure--should benefit the self-assembly of colloidal polymers built from nanoparticles. Collective plasmonic, excitonic, and magnetic properties of nanoparticle chains depend on their degree of polymerization (9-11). Nanoparticle chains have potential applications as sensors (12), nanoantennas (13), or waveguides (14), to name just a few applications, and their successful realization relies on the ability to precisely control nanopolymer structure. Recently, we reported the ability to predict the average degree of polymerization X n of nanoparticle chains for a particular self-a...

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Section: Resultsmentioning

confidence: 99%

Colloidal analogs of molecular chain stoppers

Klinkova

Thérien-Aubin

Choueiri

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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“…To solve this problem, excellent highly porous, supporting matrices to provide accessible channels for target organic molecules to contact metal nanoparticles are needed. Noble metals such as gold (Au), silver (Ag) and platinum (Pt) have been used to as catalysts (Zhu et al, 2013;Leung et al, 2012), but their expensiveness and scarcity limit their application and scope. Therefore, to degrade organic contaminants in water, it was considered urgent to develop nonnoble metal materials with effective catalytic properties that were also stable in water.…”

Section: Introductionmentioning

confidence: 99%

Cu/Cu2O/CuO loaded on the carbon layer derived from novel precursors with amazing catalytic performance

Zhao

Tan

et al. 2016

Science of The Total Environment

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• We present an effective catalyst for reductive degradation of organic dyes and phenols in water.• Compared with noble metals, Cu/Cu 2 O/ CuO@C particles are more efficient and less expensive • The porous structure provided a large contact area and channels for the pollutions and active site. , infrared spectroscopy and Raman analysis, revealed that it was composed of graphitized carbon with numerous nanoparticles (100 nm in diameter) of Cu/CuO/Cu 2 O that were uniformly distributed on internal and external surfaces of the carbon support. Gallic acid (GA) has been used as both organic ligand and carbon precursor with metal organic frameworks (MOFs) as the sacrificial template and metal oxide precursor in this green synthesis. The material combined the advantages of MOFs and Cu-containing materials, the porous structure provided a large contact area and channels for the pollutions, which results in more rapid catalytic degradation of pollutants and leads to greater efficiency of catalysis. The material gave excellent catalytic performance for organic dyes and phenols. In this study, Cu/Cu 2 O/CuO@C was used as catalytic to reduce 4-NP, which has been usually adopted as a model reaction to check the catalytic ability. Catalytic experiment results show that 4-NP was degraded approximately 3 min by use of 0.04 mg of catalyst and the conversion of pollutants can reach more than 99%. The catalyst exhibited little change in efficacy after being utilized five times. Rates of degradation of dyes, such as Methylene blue (MB) and Contents lists available at ScienceDirectScience of the Total Environment j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / s c i t o t e n v Rhodamine B (RhB) and phenolic compounds such as O-Nitrophenol (O-NP) and 2-Nitroaniline (2-NA) were all similar.

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“…In catalysis, noble metal catalysts (Au, Ag, etc) have been widely used due to their high selectivity and catalytic efficiency [1,2]. Despite the great progress achieved by far, the scarce and high-cost of noble metal resources make them uneconomic for practical application.…”

Section: Introductionmentioning

confidence: 99%

“…Herein we present a different and facile method to obtain porous carbon supported Cu/Cu 2 O composite architecture (Cu/Cu 2 O/C) by using Cu 3 (BTC) 2 (also denoted as HKUST-1) as sacrificial template and phenol formaldehyde resin as carbon precursor. The Cu/Cu 2 O/C composites possess different pore sizes ranging from micro-to macro-pores, and the Cu/Cu 2 O particles 40 nm-in-diameter distributed evenly on the internal and external surface of the porous carbon flakes, which allow the accessibility of the catalytic active sites (Cu/Cu 2 O NPs).…”

Section: Introductionmentioning

confidence: 99%

MOF derived porous carbon supported Cu/Cu 2 O composite as high performance non-noble catalyst

Niu

Liu

Cai

et al. 2016

Microporous and Mesoporous Materials

153

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a b s t r a c tPorous carbon supported copper composite (Cu/Cu 2 O/C) was synthesized with a facile, low cost and novel method and used as non-noble-metal catalyst for reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH 4 . In the synthetic strategy, metal organic framework Cu 3 (BTC) 2 (also denoted as HKUST-1) was used as both sacrificial template and copper precursor, and phenol formaldehyde resin as carbon precursor. The catalytic Cu/Cu 2 O nanoparticles (Cu/Cu 2 O NPs) about 40 nm-indiameter distributed uniformly both on the internal and external surface of the porous carbon flakes, and took up 33.38e37.56 wt% of the Cu/Cu 2 O/C composite. Compared with noble metal catalysts, the prepared composite showed comparable high catalytic activity, which was mainly due to their porous structure facilitating diffusion of reactants and products, and the high dispersion of accessible catalytic Cu/Cu 2 O NPs on porous carbon. Moreover, the synthesized catalyst can be reused for at least five cycles due to its good stability. These results confirmed that the as-prepared Cu/Cu 2 O/C is promising candidate to replace noble metal for catalytic application.

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Gold and iron oxide hybrid nanocomposite materials

Cited by 249 publications

References 119 publications

Colloidal analogs of molecular chain stoppers

Colloidal analogs of molecular chain stoppers

Cu/Cu2O/CuO loaded on the carbon layer derived from novel precursors with amazing catalytic performance

MOF derived porous carbon supported Cu/Cu 2 O composite as high performance non-noble catalyst

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