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Boron nitride encapsulated copper nanoparticles: a facile one-step synthesis and their effect on thermal decomposition of ammonium perchlorate.

Huang C, Liu Q, Fan W, Qiu X - Sci Rep (2015)

Bottom Line: Here, we developed an alternative approach to encapsulate copper nanoparticles with a chemical inertness material--hexagonal boron nitride.The wrapped copper nanoparticles not only exhibit high oxidation resistance under air atmosphere, but also keep excellent promoting effect on thermal decomposition of ammonium perchlorate.This approach opens the way to design metal nanoparticles with both high stability and reactivity for nanocatalysts and their technological application.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350002, P. R. China.

ABSTRACT
Reactivity is of great importance for metal nanoparticles used as catalysts, biomaterials and advanced sensors, but seeking for high reactivity seems to be conflict with high chemical stability required for metal nanoparticles. There is a subtle balance between reactivity and stability. This could be reached for colloidal metal nanoparticles using organic capping reagents, whereas it is challenging for powder metal nanoparticles. Here, we developed an alternative approach to encapsulate copper nanoparticles with a chemical inertness material--hexagonal boron nitride. The wrapped copper nanoparticles not only exhibit high oxidation resistance under air atmosphere, but also keep excellent promoting effect on thermal decomposition of ammonium perchlorate. This approach opens the way to design metal nanoparticles with both high stability and reactivity for nanocatalysts and their technological application.

No MeSH data available.


XPS spectra of samples.(a) B 1s, (b) N 1s, and (c) Cu 2p core-level spectra of the 25.0 wt% Cu@h-BN sample, (d) Cu 2p core-level spectrum of the 30.7 wt% Cu@h-BN sample.
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f2: XPS spectra of samples.(a) B 1s, (b) N 1s, and (c) Cu 2p core-level spectra of the 25.0 wt% Cu@h-BN sample, (d) Cu 2p core-level spectrum of the 30.7 wt% Cu@h-BN sample.

Mentions: Cu nanoparticles encapsulated by h-BN were synthesized via one step thermal decomposition of the mixture of boron oxide, urea and cupric nitrate. Figure 1 shows the powder X-ray diffraction (XRD) patterns of the samples stored in air for three months. By comparing diffraction peaks with the standard PDF cards (JCPDS card No. 85–1068 and No. 04–0836), the phase structures of h-BN and Cu can be resolved. The peaks located at 26.7° and 41.7° represent the characteristic reflections (002) and (100) of h-BN, respectively. The diffraction peaks at 43.4°, 50.5° and 74.1° correspond to the (111), (200) and (220) planes of Cu, respectively. For comparison, the XRD patterns of the freshly prepared samples are given in Fig. S1. No clear changes have been found for the diffractions from Cu between the freshly prepared samples and the samples stored for three months. Moreover, it could be found that the XRD signals for Cu gradually increase with its content increasing in the samples, which is very similar to those of Cu-Ni-Al-Co-Cr-Fe-Si alloy systems8. The diffraction intensity of h-BN is weaker and broader than those of Cu due to its low crystallinity. Note that no other peaks related to Cu oxides are observed under the detection limit and sensibility of the XRD apparatus, which can also be confirmed by the following Raman (Fig. S3) and X-ray photoelectron spectroscopy (XPS) (Fig. 2) analyses. In addition, there are two small peaks occurred at 25.3° and 31.7°, which can be attributed to the formation of NH4B5O8·4H2O (JCPDS card No. 31− 0043), as well as one small peak at 27.8° originating from B2O3 (JCPDS card No. 06–0297). This is likely due to the presence of O2, moisture and trace ammonium gas retained within h-BN layers.


Boron nitride encapsulated copper nanoparticles: a facile one-step synthesis and their effect on thermal decomposition of ammonium perchlorate.

Huang C, Liu Q, Fan W, Qiu X - Sci Rep (2015)

XPS spectra of samples.(a) B 1s, (b) N 1s, and (c) Cu 2p core-level spectra of the 25.0 wt% Cu@h-BN sample, (d) Cu 2p core-level spectrum of the 30.7 wt% Cu@h-BN sample.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4645124&req=5

f2: XPS spectra of samples.(a) B 1s, (b) N 1s, and (c) Cu 2p core-level spectra of the 25.0 wt% Cu@h-BN sample, (d) Cu 2p core-level spectrum of the 30.7 wt% Cu@h-BN sample.
Mentions: Cu nanoparticles encapsulated by h-BN were synthesized via one step thermal decomposition of the mixture of boron oxide, urea and cupric nitrate. Figure 1 shows the powder X-ray diffraction (XRD) patterns of the samples stored in air for three months. By comparing diffraction peaks with the standard PDF cards (JCPDS card No. 85–1068 and No. 04–0836), the phase structures of h-BN and Cu can be resolved. The peaks located at 26.7° and 41.7° represent the characteristic reflections (002) and (100) of h-BN, respectively. The diffraction peaks at 43.4°, 50.5° and 74.1° correspond to the (111), (200) and (220) planes of Cu, respectively. For comparison, the XRD patterns of the freshly prepared samples are given in Fig. S1. No clear changes have been found for the diffractions from Cu between the freshly prepared samples and the samples stored for three months. Moreover, it could be found that the XRD signals for Cu gradually increase with its content increasing in the samples, which is very similar to those of Cu-Ni-Al-Co-Cr-Fe-Si alloy systems8. The diffraction intensity of h-BN is weaker and broader than those of Cu due to its low crystallinity. Note that no other peaks related to Cu oxides are observed under the detection limit and sensibility of the XRD apparatus, which can also be confirmed by the following Raman (Fig. S3) and X-ray photoelectron spectroscopy (XPS) (Fig. 2) analyses. In addition, there are two small peaks occurred at 25.3° and 31.7°, which can be attributed to the formation of NH4B5O8·4H2O (JCPDS card No. 31− 0043), as well as one small peak at 27.8° originating from B2O3 (JCPDS card No. 06–0297). This is likely due to the presence of O2, moisture and trace ammonium gas retained within h-BN layers.

Bottom Line: Here, we developed an alternative approach to encapsulate copper nanoparticles with a chemical inertness material--hexagonal boron nitride.The wrapped copper nanoparticles not only exhibit high oxidation resistance under air atmosphere, but also keep excellent promoting effect on thermal decomposition of ammonium perchlorate.This approach opens the way to design metal nanoparticles with both high stability and reactivity for nanocatalysts and their technological application.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350002, P. R. China.

ABSTRACT
Reactivity is of great importance for metal nanoparticles used as catalysts, biomaterials and advanced sensors, but seeking for high reactivity seems to be conflict with high chemical stability required for metal nanoparticles. There is a subtle balance between reactivity and stability. This could be reached for colloidal metal nanoparticles using organic capping reagents, whereas it is challenging for powder metal nanoparticles. Here, we developed an alternative approach to encapsulate copper nanoparticles with a chemical inertness material--hexagonal boron nitride. The wrapped copper nanoparticles not only exhibit high oxidation resistance under air atmosphere, but also keep excellent promoting effect on thermal decomposition of ammonium perchlorate. This approach opens the way to design metal nanoparticles with both high stability and reactivity for nanocatalysts and their technological application.

No MeSH data available.