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Scientific Reports Volume 5, Article Number: 16736 (2015) Cite this article

Reactivity is very important for metal nanoparticles used as catalysts, biomaterials, and advanced sensors, but the search for high reactivity seems to conflict with the high chemical stability required for metal nanoparticles. There is a delicate balance between reactivity and stability. This can be achieved for colloidal metal nanoparticles using organic capping agents, but it is challenging for powder metal nanoparticles. Here, we developed an alternative method to encapsulate copper nanoparticles with a chemically inert material-hexagonal boron nitride. The wrapped copper nanoparticles not only show high oxidation resistance in air atmosphere, but also have a good promotion effect on the thermal decomposition of ammonium perchlorate. This method paves the way for the design of nano-catalysts with high stability and reactivity and metal nanoparticles for technical applications.

Metal nanoparticles are widely used in various fields such as electronics, photonics, biomedicine and chemistry because of their fascinating properties1,2,3,4,5,6. Most research on metal nanoparticles has focused on their size, shape and composition, rather than their stability and reactivity7,8,9,10. However, stability and reactivity are two key factors for metal nanoparticles to ensure their subsequent characterization, functional formulation and further application. Although the size of metallic materials tends to be on the nanometer scale, they become more reactive and unstable due to their high surface energy and large surface area to volume ratio. Therefore, from the point of view of surface chemistry and process, stability and reactivity seem to be contradictory, and it is difficult to achieve 12,13,14 at the same time. Therefore, it is still challenging and desirable to synthesize metal nanoparticles with high stability and strong reactivity.

Among metal nanoparticles, copper (Cu) nanoparticles have aroused great interest due to their outstanding and unique properties in catalysis, electronics and photonics4,5,6. However, Cu nanoparticles are easily oxidized under air conditions to form Cu oxides or hydroxides, thereby affecting/changing their chemical and physical properties (such as catalytic activity, conductivity)15. To avoid oxidation, anti-caking surfactants or organic end-capping agents used in the preparation process can prevent the resulting product from being oxidized and stored in solution for a long time16. However, for powdered copper nanoparticles, organic surfactants are not stable enough in the air for long periods of time or under the high temperature and oxygen-rich conditions required by many industrial catalytic processes15. From the perspective of materials science and technology applications, wrapping gas-sensitive metal nanoparticles with protective materials will be an alternative and effective strategy. Encouragingly, several such materials have recently been discovered, such as SiO2, Al2O3, carbon and boron nitride 17, 18, 19, 20, 21, 22. In addition, some encapsulated metal nanoparticles not only achieved remarkable stability, but also greatly promoted the physical and chemical properties23, 24, which is very interesting and greatly inspired people to expand the scope of practical applications of nanoparticles. For example, Joo et al. It has been found that Pt/mesoporous silica core-shell nanoparticles remain very stable at high temperatures, while exhibiting high catalytic activity for CO oxidation25. Wan and colleagues demonstrated that carbon-coated tin nanoparticles show high specific capacity and excellent cycle performance, making them a promising anode material for lithium-ion batteries26. Recently, hexagonal boron nitride (h-BN) has been successfully used as an excellent planar support for dispersing and stabilizing precious metal and copper oxide catalysts in our previous research27, 28. h-BN is a structural analogue of graphite, with significant characteristics such as chemical inertness, thermal stability, thermal conductivity and electrical insulation. Its high stability and oxidation resistance make it an ideal packaging material.

Here, we use h-BN as a protective and dispersing substrate, and encapsulate Cu nanoparticles through a one-step pyrolysis of a mixture of copper salt, boron oxide and urea. Thermal decomposition leads to the formation of h-BN and Cu nanoparticles. The formed copper nanoparticles are highly dispersed and encapsulated in layered h-BN flakes. In order to evaluate the reactivity of the prepared h-BN-encapsulated Cu nanoparticles (referred to as Cu@h-BN in this article), we studied their effect on the thermal decomposition of ammonium perchlorate (AP). AP is an oxidant, usually used as a composite solid propellant for rockets and missiles. The combustion of AP is usually promoted by transition metal oxides or bulk metal powder 29, 30, 31. We found that the Cu@h-BN composite material is stable in the air for a long time and exhibits high activity to the thermal decomposition and heat release of AP.

Through one-step thermal decomposition of the mixture of boron oxide, urea and copper nitrate, Cu nanoparticles encapsulated by h-BN were synthesized. Figure 1 shows the powder X-ray diffraction (XRD) pattern of a sample stored in the air for three months. By comparing the diffraction peaks with standard PDF cards (JCPDS card No. 85-1068 and No. 04-0836), the phase structure of h-BN and Cu can be analyzed. The peaks 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 pattern of the freshly prepared sample is given in Figure S1. There was no significant change in Cu diffraction between the freshly prepared sample and the sample stored for three months. In addition, it can be found that the XRD signal of Cu gradually increases with the increase of its content in the sample, which is very similar to the Cu-Ni-Al-Co-Cr-Fe-Si alloy system. Due to its low crystallinity, the diffraction intensity of h-BN is weaker and wider than that of Cu. Please note that no other peaks related to Cu oxides are observed under the detection limit and sensitivity of the XRD equipment, which can also be confirmed by the following Raman (Figure S3) and X-ray photoelectron spectroscopy (XPS) (Figure 2) analyze. In addition, there are two small peaks at 25.3° and 31.7°, which can be attributed to the formation of NH4B5O8·4H2O (JCPDS card number 31-0043), and a 27.8° peak from B2O3 (JCPDS card number 06-0297). This may be due to the retention of O2, moisture and traces of ammonium gas in the h-BN layer.

The XRD pattern of the synthesized Cu@h-BN sample stored in the air for three months, (a) pure h-BN, (b) 10.0 wt% Cu@h-BN, (c) 14.2 wt% Cu@h- BN, (d) 18.1 wt% Cu@h-BN, (e) 25.0 wt% Cu@h-BN, (f) 30.7 wt% Cu@h-BN.

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

In order to obtain more information about the physics and chemistry of our samples, we collected diffuse reflectance spectroscopy (DRS). As shown in Figure S2, there is a broad peak centered approximately. The Cu@h-BN sample is 570 nm, which is attributed to the local surface plasmon of Cu nanoparticles32,33. In addition, since oxygen and carbon are doped in the h-BN framework, a very slight and broad absorption band of h-BN can be observed in the visible light range. A 532 nm laser source was used to obtain the Raman spectrum of the sample. As shown in Figure S3, the Raman peak of h-BN is located at 1367 cm-1, which can be classified as a typical BN stretching vibration mode (E2g)35. Please note that for the Cu@h-BN sample, there are no obvious peaks at 220 cm-1 and 295 cm-1 due to Cu oxide 27, 36. However, the incorporation of Cu can cause significant changes in the vibration frequency of BN, indicating that there is a strong interaction between h-BN and Cu nanoparticles in Cu@h-BN composites. The peaks of BN stretching vibration are at 1340 and 1355 cm-1, and for the 25.0 wt% Cu@h-BN and 30.7 wt% Cu@h-BN samples, there are 28 and 13 cm-1 drops, respectively. Generally, the movement of E2g can occur under different strain conditions within the layer. Calizo37 and Ferrari38 have also observed similar phenomena in their work on graphene. The strong interaction between h-BN and Cu nanoparticles may be beneficial to the stability and reactivity of the Cu component.

Further use XPS to obtain detailed information on the chemical composition and elemental state of the sample. Figure 2 and S4a show the XPS spectra of the samples 25.0 wt% Cu@h-BN and 30.7 wt% Cu@h-BN. As shown in Figure 2a, the main peak of 189.9 eV and the shoulder peak of 190.8 eV in the B 1s spectrum can be assigned to the BN bond and the BO bond 27 and 28, respectively. The N 1s core XPS spectrum (Figure 2b) shows a strong photoelectron signal of 397.6 eV, which can be assigned to the BN bond, which is consistent with the value of N3- in the BN layer in the literature 40,41. In the case of the Cu 2p core energy level spectrum (Figure 2c, d), two strong peaks at 933.9 and 952.5 eV are observed, which can be designated as Cu 2p3/2 and Cu 2p1/2 spin-orbit components 42, respectively . Importantly, no satellite peaks 43, 44 corresponding to the Cu2 species were detected, excluding CuO in our sample. In addition, the Cu LMM Auger peak was observed at a kinetic energy of 918 eV (Figure S4b), similar to pure copper metal 43,44. Therefore, combining the XPS results with the above XRD, Raman analysis shows that Cu nanoparticles can be stable in the air and will not be oxidized by the protection of h-BN.

Next, use field emission scanning (SEM) and transmission electron microscope (TEM) to observe the morphology, structure and microstructure of the sample. Figure 3 shows SEM images of Cu@h-BN samples with different Cu content and commercial AP powders. As shown in Figure 3a, pure h-BN has a layered structure. After being combined with Cu, Cu particles can be easily distinguished from high-contrast images due to the high resistivity of h-BN. As shown in Figure 3b and c, Cu nanoparticles are highly dispersed, with a diameter of 40-70 nm, and are covered by h-BN flakes. In addition, the number of nanoparticles can be controlled by increasing the Cu content in the Cu@h-BN composite. Consistent with the SEM results, the TEM image shows that the Cu@h-BN composite is composed of spherical nanoparticles and flakes (Figure 4a, c). In addition, from their corresponding high-resolution TEM (HR-TEM) images (Figure 4b, d), there are two lattice spacings of 0.34 and 0.21 nm, corresponding to the (002) crystal plane and (111) of h-BN28 ) Are the crystal planes of Cu nanoparticles 45 respectively. In addition, it can be seen that the Cu nanoparticles are also surrounded by the h-BN flakes, which is in good agreement with the SEM observation. In addition, the surface analysis using energy dispersive X-ray (EDX) shown in Figure 4e shows that the sample is composed of B, N, O, and Cu, which is consistent with the XPS spectrum shown in Figure S4a. The element Mo comes from the Mo carrier used in the TEM measurement. Therefore, it can be inferred that the structure of Cu nanoparticles is under the support and encapsulation of h-BN, as shown in Figure 4f.

SEM images of (a) pure h-BN, (b) 25.0 wt% Cu@h-BN, (c) 30.7 wt% Cu@h-BN and (d) pure AP.

TEM and HRTEM images of (a,b) 25.0 wt% Cu@h-BN and (c,d) 30.7 wt% Cu@h-BN. (e) Sample EDX with 25.0 wt% Cu@h-BN. (f) Schematic diagram of the structure of Cu@h-BN.

According to the above analysis, Cu@h-BN composite materials with different Cu contents were initially used as additives to promote the thermal decomposition of AP, and an attempt was made to study the reactivity of Cu nanoparticles stabilized by h-BN. Since the thermal decomposition of AP is greatly affected by the size and morphology of AP46, the AP was observed by SEM. As shown in Figure 3d, AP exhibits non-uniformity in the size range of hundreds of nanometers to about 10 microns. Differential thermal analysis (DTA) and exothermic analysis have been carried out to study the promotion effect of Cu@h-BN composite on the thermodynamic behavior of AP (sample Cu@h-BN: AP = 2: 98 wt/ wt). The heating rate is 10 °C/min. As for AP alone (Figure 5a), an endothermic peak is observed at 246°C, which comes from the phase transition 46 from orthorhombic to cubic shape, while the two exothermic peaks in the range of 280 to 450°C are from AP decomposition. The small exothermic peak at 307 °C corresponds to the low-temperature decomposition caused by partial decomposition of AP, and the other broad peak at 391 °C is attributed to complete decomposition47. The addition of pure h-BN seems to hinder the decomposition of AP, which means that h-BN cannot be used as a good accelerator for AP decomposition. This may be due to the electrical insulation of h-BN that is not conducive to charge transfer during AP decomposition. It is encouraging that with the addition of Cu@h-BN sample, although the phase transition of AP does not change significantly, the exothermic peak of AP complete decomposition becomes sharper and shifts to a lower temperature. This means that our Cu@h-BN samples can trigger complete decomposition at lower temperatures and promote the decomposition process. In addition, the significant reduction of the complete decomposition temperature causes the two exothermic peaks to tend to integrate into one exothermic peak, which is conducive to the exothermic heat of AP and its practical application as a propellant. The promotion effect of the Cu@h-BN sample firstly increased as the Cu content increased to 25.0 wt%, and then decreased as the Cu content further increased to 30.7 wt%. Among all the samples, the Cu@h-BN sample with 25.0 wt% was found to have the highest activity. The promotion effect can be explained as the decomposition products NH3 and HClO4 are absorbed on the surface of the additive and initiate the subsequent redox reaction 47, which will be discussed below. In addition, we also studied the heat release of AP decomposition to obtain more details about the promotion effect of Cu@h-BN samples. Figure 5b shows that the presence of Cu@h-BN sample can cause more heat release than AP alone. The total heat release of AP alone and AP with Cu@h-BN sample was determined to be 1339, 1270, 1485, 1578, 1552, 1820, and 1633 J/g, respectively, indicating that the decomposition of AP is in advance of Cu@h-BN sample , Especially the 25.0 wt% Cu content of Cu@h-BN (1820 J/g). In addition, we compared the activity of fresh Cu@h-BN samples, where the Cu content was 25.0 wt%, compared with the activity of samples stored in the air for three months. It can be seen from Figure S6 that the DTA curves of the fresh sample and the stored sample are similar, which further confirms the high stability of the Cu@h-BN sample.

(A) DTA decomposed by AP in the presence of the obtained sample, (b) heat release during the exothermic process that occurred in (a).

Further study the decomposition of AP by thermogravimetric analysis (TGA). As shown in Figure 6, AP's TGA weight loss curve shows two obvious steps. One is about 10% in the range of 270-310°C, and the other is about 90% weight loss in the range of 310-440°C, corresponding to low temperature and high temperature decomposition, respectively. With the addition of Cu@h-BN sample, it was found that the decomposition of AP moved to a lower temperature. In addition, with the increase of Cu content in Cu@h-BN additives, the low-temperature and high-temperature decomposition of AP seem to be combined. It should be mentioned that the TGA weight loss curves of Cu@h-BN assisted AP with 25.0 and 18.1 wt% Cu content are closed. The Cu@h-BN 18.1 wt% Cu content curve is even lower than the Cu@h-BN 25.0 wt% Cu content curve, which is within the final smaller AP weight loss range. The final slight weight loss should not be the main contribution of AP to liberating heat. Since the promotion effect of additives on AP decomposition is usually evaluated based on the decomposition peak value and heat release, the sample content of Cu@h-BN is 25.0 wt%. Cu is considered to be the most active and used as an example for further investigation in this study. .

(a) TG of AP and Cu@h-BN mixture with different Cu content.

In order to study the effect of the amount of Cu@h-BN sample on the thermal decomposition behavior of AP, 25.0 wt% Cu@h-BN sample and AP were pre-mixed with a mass ratio of 1:99 to 10:90 to prepare the target mixture. The mixture is decomposed in a N2 atmosphere at a heating rate of 10 °C/min. As shown in Figure S5a, our sample size has no significant effect on the exothermic peak. By comparing the related heat release (Figure S5b), it can be found that the best mass ratio of Cu@h-BN sample and AP should be 2:98. In addition, it is reported that the heat release of AP is highly dependent on the heating rate of 48. Figure 7a shows the DTA curves of AP and 25.0 wt% Cu@h-BN mixture at different heating rates, namely 5, 10, 15 and 20 °C/min. It can be seen that the heating rate has a significant effect on the intensity and area of ​​the exothermic peak. As can be seen from the inset in Figure 7a, the highest heat release is achieved at a heating rate of 10°C/min. Most importantly, the activation energy (Ea) kinetic parameters of AP decomposition of Cu@h-BN samples can be derived from the temperature dependence of the exothermic peak as a function of heating rate. According to Kissinger's method 49, Ea can be written as:

(a) DTA curves of AP and 25.0 wt% Cu@h-BN (mass ratio 98:2) at different heat rates, (illustration) the corresponding heat release during the heat release process, (b) ln (β/ T2max) ) As a function of (1/Tmax). β and Tmax are the heating rate and related peak top temperature shown in (a), respectively.

Where β, Tmax, R and A represent the heating rate, peak top temperature, ideal gas constant and pre-exponential factor in °C/min, respectively. The peak top temperature Tmax can be obtained from Figure 7a. According to the above equation, according to the slope of the linear part of the ln (β/T2max) and (1/Tmax) graph, Ea is determined to be 197 kJ/mol (as shown in Figure 7b). This value is about 130 kJ/mol lower than AP alone, indicating that the presence of the Cu@h-BN sample can lower the required reaction temperature and promote the decomposition reaction.

In order to obtain more information about AP pyrolysis (intermediate) products, thermogravimetric analysis combined with mass spectrometry (TG-MS) measurement was performed, and the reaction products were analyzed in situ and related possible mechanisms were discussed. For the decomposition of pure AP (Figure 8a), NH3, NH2, NO, N2O, NO2, HNO, H2O, O2, HCl and trace amounts of Cl2 and ClO can be found at low and high temperatures. These are also found in literature 51. At the same time, these products increase sharply from the low-temperature decomposition stage to the high-temperature process, especially the products Cl2 and ClO (Figure 8a). Therefore, the promotion effect of Cu@h-BN on the high temperature decomposition process is more significant than that on the low temperature decomposition process, which can also be confirmed by the DTA and TG data in Figure 5 and Figure 6. The decomposition of AP is complex in nature, because the compound AP is composed of four elements, and the decomposition process is related to the complete oxidation of nitrogen and chlorine. There are many opinions on the thermal decomposition mechanism of AP. Bircomshaw and Newman believe that the decomposition process is driven by electron transfer from perchlorate ions to ammonium ions. In addition, Raevsky and Manelis proposed a mechanism based on electronic transitions in the energy band. However, since AP is a dielectric with a band gap of 5.6 eV, the probability of electron transfer and band-to-band transition during the decomposition process is very low. In contrast, Boldyrev46 proposed a favorable mechanism based on the transfer of protons from the cation NH4 to the anion ClO4-, which initiates and maintains the decomposition reaction. In our study, the low-temperature decomposition process is considered to start from the formation of the inner core of AP52, which is hardly affected by the Cu@h-BN sample. In other words, additives are not easy to participate in the proton transfer process in the low temperature stage. This can be confirmed by the exotherm shown in Figure 5a. On the contrary, at high temperature, the complete decomposition reaction occurs on the AP surface covering/contacting the Cu@h-BN sample. In addition, the decomposed and sublimed NH3 and HClO4 molecules react in the gas phase or in the adsorption layer on the surface of the Cu@h-BN sample. On the other hand, by-products (such as NO, N2O, H2O, O2) can also trigger secondary chemical reactions 52 in the gas phase or on the surface of the Cu@h-BN sample. The reaction can be schematically depicted in Figure 8b. To verify this hypothesis, we checked the XRD pattern of the sample after AP decomposition (Figure S7). It is found that with the appearance of CuO, the peak of Cu metal decreases. This finding is reasonable because strong oxidizing molecules such as O2, Cl2 and ClO are produced on the Cu@h-BN sample during AP decomposition at high temperature. The experimental results also show that the h-BN sheet can stabilize Cu nanoparticles to resist long-term oxidation in the air, but Cu nanoparticles are not inert and have a good effect on the decomposition of AP. In these reactions, Cu nanoparticles can enhance the heterogeneous redox reaction by promoting the charge mobility and transfer rate through the conductive metal surface or the formal oxidation/reduction state transition in the pyrolysis stage.

(a) TG-MS analysis of pure AP (left) and a mixture of AP and 25.0 wt% Cu@h-BN (mass ratio 98:2) at a heating rate of 10 °C/min, (b) Cu@h -Schematic diagram of the thermal decomposition reaction of AP catalyzed by BN.

In conclusion, we have successfully developed a feasible strategy to synthesize highly dispersed Cu nanoparticles covered by the h-BN layer through one-step thermal decomposition. Cu nanoparticles remain very stable in air at room temperature without any obvious oxidation. In addition, the high oxidation-resistant copper nanoparticles showed a significant promotion activity on the thermal decomposition of AP, indicating that the coating of the h-BN layer would not hinder the catalytic reaction that occurred on the metal surface. Therefore, the encapsulation of h-BN not only stabilizes the Cu nanoparticles, but also maintains their high activity. This method may be extended to other metal nanoparticles. This research has broad prospects for the formulation of powder metal nanoparticles for solid-solid or solid-gas hybrid catalysis and their practical applications in advanced nano-sized electronic devices.

Usually, 3 g B2O3, 6 g urea and 0.9-3.6 g Cu(NO3)2 are mixed homogeneously, then heated in a tube furnace in ammonia gas at 1250 °C for 5 hours, and then cooled to room temperature. According to the additive amount x of Cu(NO3)2. For comparison, pure h-BN was synthesized using starting reagents B2O3 and urea. The prepared samples are stored in air at room temperature.

The XRD spectrum of the sample was performed on a Bruker D8 Advance diffractometer at room temperature with Cu Kα1 radiation. The UV/Vis diffuse reflectance spectrum was obtained on the Varian Cary 500 Scan UV/Vis system. Raman spectra from 500 to 2500 cm-1 were recorded on the Renishaw inVia Raman Microphrobe under 532 nm laser excitation. XPS was analyzed on SHIMADZU (Amicus), using Al Kα X-rays as the excitation source (1486.8 eV). The morphology and microstructure of the sample were explored through the field emission scanning electron microscope on Hitachi's new generation SU8100 equipment and the transmission electron microscope on the TECNAI F30 instrument operating at 200 kV.

The reactivity of the Cu@h-BN sample was evaluated by the thermal decomposition of AP in a covered crucible under a nitrogen atmosphere. In order to study the dependence of the amount of Cu@h-BN sample on AP decomposition, AP and Cu@h-BN samples were premixed at a mass ratio of 99:1 to 90:10 to prepare the target sample. The activation energy of Cu@h-BN sample to decompose AP was explored by changing the heating rate. Thermal gravity (TG) was performed on the NETZSCH STA 449 F3 thermal analyzer, working from room temperature to 500 °C in a N2 atmosphere. The thermal behavior of the mixture was performed on a NETZSCH DTA 404 PC differential thermal analyzer (DTA) with different heating rates from room temperature to 500 °C in N2 atmosphere. The mass spectrum data was obtained on NETZSCH STA449C-QMS403C thermal gravity mass spectrometry (TG-MS).

How to cite this article: Huang, C. et al. Copper nanoparticles encapsulated by boron nitride: a simple one-step synthesis and its effect on the thermal decomposition of ammonium perchlorate. science. Rep. 5, 16736; doi: 10.1038/srep16736 (2015).

Eustis, S. & El-Sayed, MA Why gold nanoparticles are more precious than beautiful gold: Precious metal surface plasmon resonance and its enhancement of the radiation and non-radiation properties of nanocrystals of different shapes. Chemical society. Revision 35, 209–217 (2006).

Huo, FJ etc. Ultraviolet visible light (UV-Vis) reversible but fluorescence irreversible copper chemical sensor in water and its application in living cells. anus. Chemistry 84, 2219–2223 (2012).

Mackie, K., Müller, T., Zikeli, S. & Kandeler, E. Long-term copper application in organic vineyards changes the spatial distribution of soil microorganisms. Soil biochemistry. 65, 245–253 (2013).

Marimuthu, A., Zhang, J. and Linic, S. Adjust the selectivity of propylene epoxidation through plasma-mediated optical switching of the copper oxidation state. Science 339, 1590–1593 (2013).

CAS ADS article Google Scholar 

Manthiram, K., Beberwyck, BJ & Alivisatos, AP uses a dispersible nano-scale copper catalyst to enhance the electrochemical methanation of carbon dioxide. J. Morning. Chemical Society 136, 13319–13325 (2014).

Wang, J., Wang, K., Wang, FB & Xia, XH Bioinspired copper catalysts are effective in reducing and releasing oxygen. Nat. Community. 5, 1-9 (2014).

Tanori, J. & Pileni, M. uses a colloidal system as a template to control the shape of copper metal particles. Langmuir 13, 639–646 (1997).

Yeh, JW, Chang, SY, Hong, YD, Chen, SK and Lin, SJ Cu-Ni-Al-Co-Cr-Fe-Si alloy system with multiple main elements has abnormally reduced X-ray diffraction intensity. alma mater. Chemical Physics 103, 41–46 (2007).

Chen, W., Li, L., Peng, Q. & Li, Y. Polyol synthesis and chemical transformation of Cu2O nanospheres. Nano Resources 5, 320–326 (2012).

Li, L. etc. Pd-Cu2O and Ag-Cu2O mixed concave nanomaterials for effective synergistic catalysts. Angie. Chemistry International. Ed. 125, 11255–11259 (2013).

Levard, C., Hotze, EM, Lowry, GV & Brown, Jr GE Environmental transformation of silver nanoparticles: effects on stability and toxicity. environment. science. technology. 46, 6900–6914 (2012).

CAS ADS article Google Scholar 

Sohn, K., Kang, SW, Ahn S., Woo, M. & Yang, SK Fe (0) nanoparticles are used for nitrate reduction: stability, reactivity and conversion. environment. science. technology. 40, 5514–5519 (2006).

CAS ADS article Google Scholar 

Ge, J., Zhang, Q., Zhang, T. & Yin, Y. Core-satellite nanocomposite catalyst protected by porous silica shell: controllable reactivity, high stability and magnetic recyclability. Angie. Chemistry International. Ed. 120, 9056–9060 (2008).

Davis, SC and Klabunde, KJ Unsupported small metal particles: preparation, reactivity and characterization. Chemistry Rev. 82, 153–208 (1982).

Hengne, AM & Rode, CV Cu-ZrO 2 nanocomposite catalyst is used for selective hydrogenation of levulinic acid and its esters to γ-valerolactone. green Chemistry. 14, 1064–1072 (2012).

Crooks, RM, Zhao, M., Sun, L., Chechik, V. & Yeung, LK Dendrimer-Encapsulated Metal Nanoparticles: Synthesis, Characterization and Applications to Catalysis. Cumulative Chemical Reservoir 34, 181–190 (2001).

Ghosh, Chaudhuri, R. & Paria, S. Core/shell nanoparticles: categories, properties, synthesis mechanisms, characterization and applications. Chemistry Rev. 112, 2373–2433 (2012).

Ikeda, S. et al. Ligand-free platinum nanoparticles encapsulated in a hollow porous carbon shell act as a highly active heterogeneous hydrogenation catalyst. Angie. Chemistry International. Ed. 118, 7221–7224 (2006).

Yoo, JW, Hathcock, D. and El-Sayed, MA characterization of Pt nanoparticles encapsulated in Al2O3 and their catalytic efficiency in propylene hydrogenation. J. Physics. Chemistry A 106, 2049–2054 (2002).

Maeda, K. et al. Noble metal/Cr2O3 core/shell nanoparticles act as a co-catalyst for photocatalytic overall water splitting. Angie. Chemistry International. Ed. 118, 7970–7973 (2006).

Hirano, T., Oku, T. and Suganuma, K. Formation of gold and iron oxide nanoparticles encapsulated in boron nitride sheets. Angie. Chemistry International. Ed. 9, 855–857 (1999).

Oku, T., Kusunose, T., Niihara, K. & Suganuma, K. Chemical synthesis of silver nanoparticles encapsulated in boron nitride nanocages. J. Matt. Chemistry 10, 255–257 (2000).

Arnal, PM, Comotti, M. & Schüth, F. High temperature stable catalyst encapsulated by hollow spheres. Angie. Chemistry International. Ed. 118, 8404–8407 (2006).

Lee, JF, etc. The shell isolates the nanoparticles to enhance Raman spectroscopy. Nature 464, 392–395 (2010).

CAS ADS article Google Scholar 

Joo, SH et al. Thermally stable Pt/mesoporous silica core-shell nanocatalyst for high temperature reactions. Nat Mater 8, 126–131 (2009).

CAS ADS article Google Scholar 

Zhang, W.-M. Wait. Tin nanoparticles encapsulated in elastic hollow carbon spheres are used as high-performance anode materials in lithium-ion batteries. Senior Matt 20, 1160–1165 (2008).

Huang, C., Ye, W., Liu, Q. & Qiu, X. Cu2O octahedrons dispersed on h-BN nanosheets are used for the reduction of p-nitrophenol. ACS application pad. Interface 6, 14469–14476 (2014).

Huang, C. etc. Stable colloidal boron nitride nanosheet dispersion and its potential application in catalysis. J. Matt. Chemistry A 1, 12192–12197 (2013).

Zhu, J., Liang, Y. & Liu, W. The effect of new phosphazene additives on Z-DOL tribological properties in steel-to-steel contact. International Tribology 37, 333–337 (2004).

Wang, Y., Zhu, J., Yang, X., Lu, L. & Wang, X. Preparation of NiO nanoparticles and their catalytic activity for the thermal decomposition of ammonium perchlorate. Rechim. Journal 437, 106–109 (2005).

Said, AA & Al-Qasmi, R. The role of copper cobaltate spinel CuxCo3-xO4 in the thermal decomposition of ammonium perchlorate. Rechim. Journal 275, 83-91 (1996).

Pedersen, DB & Wang, S. Surface plasmon resonance spectra of copper nanoparticles with a diameter of 2.8 ± 0.5 nm in the near and far fields. J. Physics. Chemistry C 111, 17493-17499 (2007).

Zhang, P. et al. Easily prepare multifaceted copper nanocrystals with high catalytic activity for the reduction of p-nitrophenol. J. Matt. Chemistry A 1, 1632–1638 (2013).

CAS ADS article Google Scholar 

Lei, W., Portehault, D., Liu, D., Qin, S. & Chen, Y. Porous boron nitride nanosheets for effective water cleaning. Nat. Community. 4, 1777 (2013).

Gorbachev, RV, etc. Looking for single-layer boron nitride: optical and Raman characteristics. Junior 7, 465–468 (2011).

Zhang, Q. etc. CuO nanostructures: synthesis, characterization, growth mechanism, basic characteristics and applications. Edit. Scientific materials. 60, 208–337 (2014).

Calizo, I. etc. Raman nanometrics of graphene: temperature and substrate effects. Solid public. 149, 1132–1135 (2009).

CAS ADS article Google Scholar 

Ferrari, A. etc. Raman spectra of graphene and graphene layers. physics. Pastor Wright. 97, 187401 (2006).

CAS ADS article Google Scholar 

Ci, L. etc. Atomic layer of mixed boron nitride and graphene domains. Nat. Material 9, 430–435 (2010).

CAS ADS article Google Scholar 

Nazarov, AS etc. Functionalization and dispersion of hexagonal boron nitride (h-BN) nanosheets treated with inorganic reagents. Chem.-Aslan J 7, 554 (2012).

Shi, Y. etc. The chemical vapor deposition method synthesizes a few-layer hexagonal boron nitride film. Nano Jean. 10, 4134–4139 (2010).

CAS ADS article Google Scholar 

Wagner, CD Handbook of X-ray Photoelectron Spectroscopy: Standard Data Reference Book for X-ray Photoelectron Spectroscopy (eds Muilenberg, GE) Ch. 2, 82–83 (Perkin-Elmer, 1979).

Ghodselahi, T., Vesaghi, M., Shafiekhani, A., Baghizadeh, A. & Lameii, M. Cu@Cu2O XPS study of core-shell nanoparticles. Application surfing. science. 255, 2730–2734 (2008).

CAS ADS article Google Scholar 

Fox, EB, etc. Characterization of CeO2-supported Cu-Pd bimetallic catalyst for oxygen-assisted water gas shift reaction. J. Cartel. 260, 358–370 (2008).

Chang, Y., Lye, ML & Zeng, HC Large-scale synthesis of high-quality ultra-long copper nanowires. Langmuir 21, 3746–3748 (2005).

Boldyrev, V. Thermal decomposition of ammonium perchlorate. Rechim. Journal 443, 1–36 (2006).

Chen, L., Li, L. & Li, G. Synthesis of CuO nanorods and their catalytic activity for the thermal decomposition of ammonium perchlorate. J. Alloy Compound 464, 532–536 (2008).

L, L. Properties of the catalytic activity of CoO nanocrystals in the thermal decomposition of ammonium perchlorate. Inorganic. Chemistry 47, 8839–8846 (2008).

Starink, MJ A new method to derive activation energy from experiments conducted at a constant heating rate. Rechim. Journal 288, 97–104 (1996).

Patil, PR, Krishnamurthy, VEN & Joshi, SS The effect of nano-copper oxide and copper chromite on the thermal decomposition of ammonium perchlorate. Propellants, explosives, fireworks. 33, 266–270 (2008).

Jacobs, MC & Whitehead, HM Decomposition and combustion of ammonium perchlorate. Chemistry Rev. 69, 551–590 (1969).

Chaturvedi, S. & Dave, PN uses nano metal as a catalyst for the thermal decomposition of ammonium perchlorate. J. Saudi Chemical Society. 17, 135–149 (2011).

The authors thank the National Natural Science Foundation of China (Grants U1305242, 21273038, 21543002, and 113055091) for funding.

State Key Laboratory of Energy and Environmental Photocatalysis, School of Chemistry, Fuzhou University, Fuzhou 350002

Huang Caijin, Liu Qiuwen, Fan Wenjie, Qiu Xiaoqing

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CH and XQ conceived and designed experiments. QL mainly conducts sample preparation and XRD, SEM, DRS TG and DTA analysis. CH and WF were analyzed by XPS, TEM, Raman and TG-MS. XQ suggests the role of the sample in possible reaction mechanisms. CH and QL co-authored the manuscript. XQ edited the manuscript. All authors discussed the results and approved the manuscript.

The author declares that there are no competing economic interests.

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Huang, C., liu, Q., Fan, W. etc. Copper nanoparticles encapsulated by boron nitride: a simple one-step synthesis and its effect on the thermal decomposition of ammonium perchlorate. Scientific Report 5, 16736 (2015). https://doi.org/10.1038/srep16736

DOI: https://doi.org/10.1038/srep16736

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