Molecular Level Design of Nitrogen-Doped Well-Defined Microporous Carbon Spheres for Selective Adsorption and Electrocatalysis

Abstract

Nitrogen-doped porous carbon spheres have attracted great interest in diversified fields owing to their unique physical and chemical properties. However, the synthesis of nitrogen-doped porous carbon spheres with hierarchical superstructures and refined micropore structures is still a challenge. Herein, we develop a molecular-scale silica templating strategy to prepare nitrogen-doped microporous carbon spheres (MCSSs) with high porosity and a well-defined micropore structure. Octa­(aminophenyl) polyhedral oligomeric silsesquioxane is used as a building block in MCSS precursors to provide precise molecular-scale templating and nitrogen doping. The morphology of MCSSs can be easily tuned by choosing the proper solvent. The as-synthesized MCSS with a large surface area (2036 m2 g–1), narrow micropore size distribution, nitrogen doping, and hierarchical geometry can serve as an efficient selective adsorbent for CO2 and organic pollutants. Furthermore, the MCSS decorated with Fe–N–C active sites (MCSS–Fe) shows enhanced electrocatalytic ORR activity in alkaline solution. This novel approach may open a new avenue for controllable fabrication of porous carbon spheres with desired geometry and well-designed pore structure and show potential applications in selective adsorption and catalysis.

Ultrasensitive Dopamine Detection at Co3O4-Anchored N-Doped Hollow Mesoporous Carbon Nanospheres

“…Because of pyridine N, which is bonded with two carbon atoms and is positioned at the edges of the N-doped carbon structure, it stimulates higher disorders in the resulting carbon products. Besides, the graphite N bonded with three carbon atoms in the N-doped carbon structure improves the stability and conductivity of the N-doped carbon product. ,, Here, the attained N species percentages are listed in Table S4. In Table S4, the pyridine N concentrations increase up to 0.2 g of loading and then decrease in 0.3 g of loading, whereas the graphite N concentration decreases up to 0.2 g of loading and then increases in 0.3 g of loading.…”

“…Besides, the graphite N bonded with three carbon atoms in the N-doped carbon structure improves the stability and conductivity of the N-doped carbon product. 34,49,53 Here, the attained N species percentages are listed in Table S4. In Table S4, the pyridine N concentrations increase up to 0.2 g of loading and then decrease in 0.3 g of loading, whereas the graphite N From these observations, we concluded that the 0.2 g of loading with a single-step addition of precursors is highly appropriate for promoting the higher concentrations of pyridine N and Co 3+ active centers and its Co 3+ /Co 2+ ratio, which may promote the sensing analysis of dopamine.…”

“…In addition, this heterogeneous coating process significantly reduces the incompatible interface between the carbon/nitrogen precursor and the silica template. These lead to low carbon product yield, which affects their surface properties including surface area, mesoporosity, and carbon shell thickness. , To solve these issues, we recently prepared Co 3 O 4 /NDHCS with silica spheres and decorated N and Co precursors by a single-step synthesis process. The resulting Co 3 O 4 /NDHCS material with the optimal amount of Co precursor loaded significantly modified the specific surface area, carbon sphere thickness, and defect site density of the material.…”

Simultaneous Removal of COD, NH3-N, and Turbidity from Sanitary Landfill Leachate using CB-PAC Particles: Isotherm Modelling and Treatment Assessment

“…Chemical adsorption accounts for the majority of the adsorption in micropores in the type I isotherm. Due to the larger pore volume, adsorption has not taken place in macropores, and adsorbate is tightly attached to the micropores (Koyuncu and Kul 2020;Chen et al 2021;Gong et al 2022). The adsorption and desorption isotherms of CB-PAC loaded with pollutants were displayed in Fig.…”

Revealing the Pore Size-Dependent Sorption Mechanism of Toluene and Cetane in Porous Carbon by Nuclear Magnetic Resonance

“…Over the past decades, various carbonaceous materials with different pore structures have been explored for adsorption applications. − Typically, microporous carbon with a large surface area can effectively capture small molecules with a size of less than 1 nm in all three dimensions since they can easily diffuse and be adsorbed in the micropores (<2 nm) of activated carbons (ACs). In contrast, mesoporous carbon with sufficient transportation channels exhibits an advantage for adsorbing larger molecules with a size exceeding 1.5 nm in one dimension at least. , In any case, the adsorption/desorption behaviors of petroleum hydrocarbons are dominated by interfacial interactions, such as hydrophobic interaction and van der Waals force.…”