Xiaoqing Qiu

Dispersed Cu2O Octahedrons on h-BN Nanosheets for p-Nitrophenol Reduction

We demonstrate here that two-dimensional boron nitride (h-BN) nanosheets can be employed as a robust supporting substrate to incorporate function metal oxides. The Cu2O@h-BN composites are thus obtained by dispersing Cu2O octahedrons on the surfaces of h-BN nanosheets. The -OH and -NH groups on the surfaces of h-BN nanosheets are found to be beneficial for anchoring Cu2O octahedrons. Moreover, the Cu2O@h-BN composites exhibit superior activity for the reduction of p-nitrophenol to pure Cu2O crystals and h-BN nanosheets. The h-BN component in the composites plays a critical role in the formation and adsorbing of the p-nitrophenolate ions, and, at the same time, Cu2O components react with brohydride ions and transfer a surface hydrogen species and electrons, resulting in the reduction of p-nitrophenol into p-aminophenol. Our results provide a new approach for the rational design and development of metal oxides composites and open the way to a range of important applications of h-BN-based materials.

Stable colloidal boron nitride nanosheet dispersion and its potential application in catalysis

Hexagonal boron nitride (h-BN) nanosheets, a promising layered material, have drawn more and more attention in recent years. In this study, a simple method has been developed to prepare stable colloidal h-BN nanosheet dispersion with high concentration in ethylene glycol based on the matching of the surface energies of h-BN and the surface tension of the solvent. It is found that bulk h-BN can be directly exfoliated and dispersed in ethylene glycol solvent with the assistance of sonication to form stable h-BN nanosheets with a few layers. Furthermore, the stable colloidal h-BN nanosheets have been demonstrated to be good carriers to support and disperse noble metal nanoparticles such as Ag, Au, and Pt with high catalytic activity for the reduction of p-nitrophenol. Our results suggest that stable colloidal h-BN dispersion with high concentration in ethylene glycol could open the way to a range of important applications of h-BN based materials.

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

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.

The release of hydrogen from ammonia borane over copper/hexagonal boron nitride composites

Facile solution-phase synthesis of copper nanoparticles dispersed on h-BN via a solvothermal method is proposed for the hydrolytic dehydrogenation of ammonia borane. We found that the earth-abundant copper nanoparticles were highly stabilized on h-BN nanosheets. The resulting Cu/h-BN composites exhibited high catalytic activity and good recycling performance for hydrogen generation from the hydrolysis of ammonia borane under mild reaction conditions. Furthermore, the kinetics of the hydrolysis reaction were also investigated by varying the concentration of ammonia borane, the amount of catalyst, and the reaction temperature. An activation energy of 23.8 kJ mol−1 was measured for the hydrolysis reaction catalyzed by the 29.4 wt% Cu/h-BN sample, which is lower than most of the reported values for other catalysts. This study demonstrates that Cu/h-BN nanocomposites can act as a potential non-precious and effective catalyst for hydrogen generation from the hydrolysis of ammonia borane.