Space‐Confined Synthesis of ZIF‐67 Nanoparticles in Hollow Carbon Nanospheres for CO₂ Adsorption

Abstract

The synthesis of HCSs based core-shell structured nanocomposite can offer many benefits and potential applications. First, the remarkable durability stemming from the carbon framework would be highly beneficial for enduring harsh reaction conditions including acidic, alkaline, and organic regent. [4] Secondly, meso-/ micropores distributed on the surface of carbon shell can provide pathways for the diffusion of mass, which would reduce the diffusion resistance. [6] Last but not the least, the presence of huge inner space of HCSs with respect to the volume of carbon shell itself affords a huge reaction site. Therefore, it is important to experimentally and theoretically investigate the inner space of HCSs-based nanocomposites with controllable sizes for their optimum utilization.Zeolitic imidazole frameworks (ZIFs) with tetrahedral network topologies are a subclass of metal-organic frameworks (MOFs) composed of transition metals (Co, Cu, Zn, etc.) linked by imidazole ligands, which have attracted extensive interest since the original report by Yaghi and co-workers. [16,17] High porosity originating from high crystallinity and regular topology structure makes ZIFs one of the best porous materials for the selective capture of CO 2 . [18][19][20][21][22][23][24][25][26][27] The outstanding chemical and thermal stability of ZIFs are also favorable for its application under harsh conditions. [28][29][30][31][32][33][34][35] It is well established that the surface-to-volume ratio and total porosity of ZIFs are inversely related to its size, and have a significant influence on the adsorption capacity. [36,37] In this regard, reducing ZIFs to nanoscale size is favorable for increasing specific surface area and total porosity as well as enhancing uptake and selectivity.In this context, we report the synthesis of ZIF-67@HCSs material via a space-confined strategy, and its application for CO 2 capture. The as-synthesized ZIF-67@HCSs exhibited a unique core-shell structure composed of single microporous carbon shell and several nanoscale ZIF-67 cores. Due to the nanoconfined environment inside HCSs, these nanoreactors outperformed the conventional solution-based synthesis. [38] The results showed that:(1) the huge inner space of HCSs could be fully utilized without volume expansion, thus enhancing the tap density; (2) spaceconfined synthesis could control the size and morphology of ZIF-67 nanoparticles; (3) high chemical and thermal stability of ZIF-67 nanoparticles protected by hydrophobic carbon shell can avoid the moisture effects for real postcombustion gas separation, and therefore enhance the long-term stability. As expected, the ZIF-67@HCSs endowed with controlled morphology and high porosity exhibited outstanding adsorption capacity for CO 2 .Herein, the design and synthesis of ZIF-67 nanoparticles (NPs) with tunable size grown inside hollow carbon nanospheres (ZIF-67@HCSs) via a space-confined strategy is reported. HCSs are first prepared via pyrolysis of polystyrene@polypyrrole (PS@PPy) composite nanospheres. Furthe...

Space‐Confined Yolk‐Shell Construction of Fe3O4 Nanoparticles Inside N‐Doped Hollow Mesoporous Carbon Spheres as Bifunctional Electrocatalysts for Long‐Term Rechargeable Zinc–Air Batteries

“…In the secondary pyrolysis process, N/HCSs‐P can control the confined growth of metal oxide nanoparticles inside the carbon sphere. Similar strategies are also used in other systems, such as yolk‐shell MoS 2 @C nanospheres, [ 29 ] ZIF‐67@HCSs, [ 30 ] etc. According to the morphology characterization, it can be found that the particle size of metal oxide nanoparticles increases with the increase of iron source (Figure S5, Supporting Information and Figure 1c–f).…”

“…Herein, with the special capillary effect of mesoporous carbon shell, the adsorbed iron ions are locked in the cavity of carbon sphere, and Fe 3 O 4 nanoparticles grow on the inner wall of N‐doped hollow carbon spheres (Fe x @N/HCSs) after thermal condensation. [ 29,30 ] The solid mesoporous carbon spheres can effectively protect iron oxide nanoparticles from falling off and agglomeration, and also ensure the full circulation of electrolyte and oxygen molecules, making each core–void–shell configuration an independent and efficient ORR/OER active ecosystem. Unique material properties endow Fe x @N/HCSs with high electrocatalytic activity toward ORR/OER in terms of low overpotential, fast kinetic reaction rate, high current density and excellent durability.…”

Amino-1H-tetrazole-regulated high-density nitrogen-doped hollow carbon nanospheres for long-life Zn–air batteries

“…S6, † a typical H-4 isotherm corresponding to an obvious hysteresis loop was observed, indicating the characteristics of micropores/macropores derived from capillary condensation in all samples. 42,43 Notably, G&P N-HCS exhibited the highest adsorption capability, such that the resulting SBET and PSD were superior to that of either HCS or N-HCS. Detailed textural parameters are summarized and displayed in Fig.…”

Nanoscale Metal‐Organic Frameworks: Synthesis, Biocompatibility, Imaging Applications, and Thermal and Dynamic Therapy of Tumors

“…For example, Yan and co‐workers have used hollow carbon nanospheres as the restricted areas to form ZIF‐67 nanoparticles with tunable size. The continuous processes of producing core–shell ZIF‐67@HCSs nanospheres were characterized by transmission electron microscope (TEM) images, then they observed the changes of this complexes after adjusting the size of ZIF‐67 differently to verify the controllability of size …”