Search Results (3)

The preparation of mesoporous carbonaceous materials with particularly adjustable morphology is currently a hot area of research in mesoporous materials. Herein, a novel approach is reported for the construction of N-doped multicavity mesoporous carbon nanoparticles (NMMCNs) based on the “emulsion swelling–acid curing mechanism” using a nanoemulsion assembly method under a high-speed shearing force. Intriguingly, this approach adopted a novel acid (HCl) curing procedure. Impressively, the morphology evolution from an internal multicavity to a single cavity and then to a non-cavity interior structure could be accomplished by simply varying the synthesis parameters. Additionally, this synthesis approach ingeniously overcame the following problems: (i) technically, the employment of high temperatures and high pressures in traditional hydrothermal reaction curing environments is avoided; (ii) this approach removes the requirement for silicon coating, which provides a limited pyrolysis condition, to obtain a multi-chamber structure. Resveratrol (Res) is an insoluble natural medicine and was successfully loaded into NMMCNs, thereby the Res–NMMCNs delivery system was constructed. Importantly, the Res–NMMCNs delivery system could still retain the antitumor and antioxidant activity of Res in vitro. Full article

Carbon-based nanomaterials, particularly in the form of N-doped networks, are receiving the attention of the catalysis community as effective metal-free systems for a relatively wide range of industrially relevant transformations. Among them, they have drawn attention as highly valuable and durable catalysts for the selective hydrogen sulfide oxidation to elemental sulfur in the treatment of natural gas. In this contribution, we report the outstanding performance of N-C/SiC based composites obtained by the surface coating of a non-oxide ceramic with a mesoporous N-doped carbon phase, starting from commercially available and cheap food-grade components. Our study points out on the importance of controlling the chemical and morphological properties of the N-C phase to get more effective and robust catalysts suitable to operate H₂S removal from sour (acid) gases under severe desulfurization conditions (high GHSVs and concentrations of aromatics as sour gas stream contaminants). We firstly discuss the optimization of the SiC impregnation/thermal treatment sequences for the N-C phase growth as well as on the role of aromatic contaminants in concentrations as high as 4 vol.% on the catalyst performance and its stability on run. A long-term desulfurization process (up to 720 h), in the presence of intermittent toluene rates (as aromatic contaminant) and variable operative temperatures, has been used to validate the excellent performance of our optimized N-C²/SiC catalyst as well as to rationalize its unique stability and coke-resistance on run. Full article

Novel N-doped carbon nanonet flakes (NCNFs), consisting of three-dimensional interconnected carbon nanotube and penetrable mesopore channels were synthesized in the assistance of a hybrid catalytic template of silica-coated-linear polyethyleneimine (PEI). Resorcinol-formaldehyde resin and melamine were used as precursors for carbon and nitrogen, respectively, which were spontaneously formed on the silica-coated-PEI template and then annealed at 700 °C in a N₂ atmosphere to be transformed into the hierarchical 3D N-doped carbon nanonetworks. The obtained NCNFs possess high surface area (946 m² g⁻¹), uniform pore size (2–5 nm), and excellent electron and ion conductivity, which were quite beneficial for electrochemical double-layered supercapacitors (EDLSs). The supercapacitor synthesized from NCNFs electrodes exhibited both extremely high capacitance (up to 613 F g⁻¹ at 1 A g⁻¹) and excellent long-term capacitance retention performance (96% capacitive retention after 20,000 cycles), which established the current processing among the most competitive strategies for the synthesis of high performance supercapacitors. Full article