Ammonia-free preparation of Ag@SiO 2 core/shell nanoparticles

Li, Zhipeng; Jia, Lifeng; Li, Yueming; He, Tianhu; Li, Xuemei

doi:10.1016/j.apsusc.2015.03.159

Cited by 30 publications

(22 citation statements)

References 23 publications

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“…Furthermore, for core-shell particles, single small Ag cores appear to be more dominant in S3 than in S1 and S2. The images ( Figure 5 ) confirm that the Ag cores were not etched away, a finding contrary to some earlier observations for ammonia catalysed synthesis, where hollow spheres were observed around Ag particles [ 34 ]. CTAB functions as both a stabilizer and a template [ 20 , 48 ], as well as prevents the newly formed Ag from rapid aggregation [ 10 ].…”

Section: Resultscontrasting

confidence: 55%

“…DMA offers two advantages over ammonia: (i) DMA allows higher reproducibility for synthesizing silica shells due to its low vapour pressure and (ii) an appropriate amount of DMA prevents dissolution of silver and avoids formation of a [Ag(NH 3 ) 2 ] + complex due to etching of the Ag core with ammonia [ 1 , 13 , 33 ]. However, Ag core etching is still observed in the presence of a high concentration of DMA [ 34 ]. Hydrolysis Si(OR) 4 + H 2 O ↔ HO–Si(OR) 3 + ROH Alcohol condensation (OR) 3 Si–OR + HO–Si(OR) 3 ↔ (OR) 3 Si–O–Si(OR) 3 + ROH Water condensation (OR) 3 Si–OH + HO–Si(OR) 3 ↔ (OR) 3 Si–O–Si(OR) 3 + H 2 O R = alkyl group …”

Section: Introductionmentioning

confidence: 99%

“…The use of sodium hydroxide (NaOH) as a catalyst for silica layer formation has been shown to significantly prevent etching of Ag cores [ 1 , 20 , 34 , 35 ]. To date, very limited research has been executed on the preparation of Ag@mesoporous SiO 2 composites using Ag NPs of size ranging from 20 to 100 nm with sodium hydroxide (NaOH) as a catalyst.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Ethanol on Ag@Mesoporous Silica Formation by In Situ Modified Stöber Method

Chen

Granbohm

et al. 2018

Nanomaterials

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Tunable core-shell Ag@Mesoporous SiO2 spheres were synthesized via an in situ modified Stöber approach by varying the amount of ethanol (EtOH) expanding their potentials in many applications. Mesoporous silica was generated by adding tetraethyl orthosilicate (TEOS) to the mixture of colloidal Ag particles prepared by reducing silver nitrate (AgNO3) with L-ascorbic acid and using hexadecyltrimethylammonium bromide (CTAB) as a template at the presence of ethanol and sodium hydroxide (NaOH) at pH 10 as a catalyst. The average sizes of the Ag cores at the three increasing volumes of ethanol were ~47 ± 6, 36 ± 4, and 11 ± 5 nm, while the silica particle size and the thickness of the silica shells increased, resulting in a blueshift of localized surface plasmon resonances (LSPR) of the Ag NPs. The corresponding specific surface areas of silica particles were 356 ± 10, 419 ± 20 and 490 ± 25 m2 g−1, and average pore diameters varied from 5.7, 5.0 to 3.3 nm according to BET and BJH analyses. TEM studies confirmed the core-shell structure, pore sizes and shapes of mesoporous shells. The dissolution tests demonstrated that the release of Ag from the powder samples is pH-sensitive and time-dependent.

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Section: Resultscontrasting

confidence: 55%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effect of Ethanol on Ag@Mesoporous Silica Formation by In Situ Modified Stöber Method

Chen

Granbohm

et al. 2018

Nanomaterials

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“…30 Moreover, such composites are characterized by slowly discharge of metallic ions from the silica matrix in a long period of time. 29 It is worth to mention, that in many cases the effectiveness of those nanocomposites depends strongly on their manufacturing techniques; like chemical reactions, [31][32][33][34][35] solgel 36 or sputtering deposition. 14 In this paper, we report a chemical synthesis of copper-and silver-silica dioxide nanocomposites (NCs) in the form of nanopowders.…”

Section: Introductionmentioning

confidence: 99%

Unique properties of silver and copper silica-based nanocomposites as antimicrobial agents

et al. 2017

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“…Silica nanomaterial was one of the suitable substrates because of material availability and environmental friendly [3,7,[9][10][11][12]. In recent years, many silicon oxide nanostructures have been studied to assemble AgNPs via different methods include chemical plating [13][14][15], ultrasonication [16], in situ assembly and in situ reduction [12,17,18], electro static interaction [19] etc.…”

Section: Introductionmentioning

confidence: 99%

Ternary Ag nanoparticles/natural-magnetic SiO2-nanowires/reduced graphene oxide nanocomposites with highly visible photocatalytic activity for 4-nitrophenol reduction

et al. 2018

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Agglomerate and reuse limit the promising application of silver nanoparticles (AgNPs) as catalyst. To eliminate those disadvantages, herein, Fe-containing silica nanowires (SiO 2 NWs) and reduced graphene oxide (RGO) are used as suitable substrates to prepare AgNPs/SiO 2 NWs/RGO nanocomposite via self-assembly approach. The nanocomposite mostly assembled with each other via intermolecular hydrogen bond and electrostatic adsorption to form a three-dimensional network structure. The AgNPs/SiO 2 NWs/RGO nanocomposite exhibit excellent photocatalytic activity for 4-nitrophenol reduction by NaBH 4 , originating from that the nearly mono-dispersed AgNPs are adhered on the surface of the SiO 2 NWs and RGO, allowing the effective contact of reactants with catalyst and facilitating the electron transfer between them in the reaction. The obtained nanocomposites exhibit the superior stability and can be easily recovered with their fully catalytic activities due to the hydrophobic and magnetic properties of the nanocomposites. It shows the great prospect for the 4-NP reduction in practice and is promising for wide applications in visible light catalytic reaction.

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Ammonia-free preparation of Ag@SiO 2 core/shell nanoparticles

Cited by 30 publications

References 23 publications

Effect of Ethanol on Ag@Mesoporous Silica Formation by In Situ Modified Stöber Method

Effect of Ethanol on Ag@Mesoporous Silica Formation by In Situ Modified Stöber Method

Unique properties of silver and copper silica-based nanocomposites as antimicrobial agents

Ternary Ag nanoparticles/natural-magnetic SiO2-nanowires/reduced graphene oxide nanocomposites with highly visible photocatalytic activity for 4-nitrophenol reduction

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