Nitrogen-doped Hollow Carbon Nanospheres Research Articles

Controllable Synthesis of Functional Hollow Carbon Nanostructures with Dopamine As Precursor for Supercapacitors.

N-doped hollow carbon spheres (N-HCSs) are promising candidates as electrode material for supercapacitor application. In this work, we report a facile one-step synthesis of discrete and highly dispersible N-HCSs with dopamine (DA) as a carbon precursor and TEOS as a structure-assistant agent in a mixture containing water, ethanol, and ammonia. The architectures of resultant N-HCSs, including yolk-shell hollow carbon spheres (YS-HCSs), single-shell hollow carbon spheres (SS-HCSs), and double-shells hollow carbon spheres (DS-HCSs), can be efficiently controlled through the adjustment of the amount of ammonia. To explain the relation and formation mechanism of these hollow carbon structures, the samples during the different synthetic steps, including polymer/silica spheres, carbon/silica spheres and silica spheres by combustion in air, were characterized by TEM. Electrochemical measurements performed on YS-HCSs, SS-HCSs, and DS-HCSs showed high capacitance with 215, 280, and 381 F g(-1), respectively. Moreover, all the nitrogen-doped hollow carbon nanospheres showed a good cycling stability 97.0% capacitive retention after 3000 cycles. Notably, the highest capacitance of DS-HCSs up to 381 F g(-1) is higher than the capacitance reported so far for many carbon-based materials, which may be attributed to the high surface area, hollow structure, nitrogen functionalization, and double-shell architecture. These kinds of N-doped hollow-structured carbon spheres may show promising prospects as advanced energy storage materials and catalyst supports.

Synthesis of nitrogen-doped hollow carbon nanospheres for CO2capture

Here, we report the synthesis of nitrogen-doped hollow carbon nanospheres (N-HCSs) via a two-step Stöber method. The resultant N-HCSs possess a uniform size of ∼220 nm, a high nitrogen loading content of 14.8 wt% and a high surface area of 767 m(2) g(-1), as well as exhibit a considerable performance for CO2 capture with a capacity of 2.67 mmol g(-1) and a high selectivity in a mixture gas (N2 or O2).

Water Dispersible, Highly Graphitic and Nitrogen‐Doped Carbon Nanobubbles

Dispersible, highly graphitic, and nitrogen-doped carbon hollow nanospheres (25-90 nm), termed 'nanobubbles', are prepared via confined carbonization through a silica nanocasting technique. Poly(ionic liquid) nanoparticles are employed as easy-to-make and multifunctional templates, which simultaneously act as both the carbon and nitrogen source. The promising potential of the nanobubbles in oxygen reduction reactions for fuel cells is demonstrated.