Huang Ke-Xin, Hua Junhui, Chang Gang-Gang, Li Zhaohuai, Tian Ge, Chen Min-Jie, Li Jia-Xin, Ke Shan-Chao, Yang Xiao-Yu, Chen Banglin
School of Chemistry, Chemical Engineering and Life Science, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, Hubei, 430070, China.
Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249-0698, USA.
Small. 2021 Jun;17(22):e2002811. doi: 10.1002/smll.202002811. Epub 2020 Jul 30.
Carbon-based nanomaterials have been widely utilized in catalysis and energy-related fields due to their fascinating properties. However, the controllable synthesis of porous carbon with refined morphology is still a formidable challenge due to inevitable aggregation/fusion of resulted carbon particles during the high-temperature synthetic process. Herein, a hierarchically oriented carbon-structured (fiber-like) composite is fabricated by simultaneously taking advantage of a confined pyrolysis strategy and disparate bond environments within metal-organic frameworks (MOFs). In the resultant composite, the oriented carbon provides a fast mass (molecule/ion/electron) transfer efficiency; the doping-N atoms can anchor or act as active sites; the mesoporous SiO (mSiO ) shell not only effectively prevents the derived carbon or active metal nanoparticles (NPs) from aggregation or leaching, but also acts as a "polysulfide reservoir" in the Li-S batteries to suppress the "shuttle" effect. Benefiting from these advantages, the synthesized composite Pd@NDHPC@mSiO (NDHPC means N-doped hierarchically porous carbon) exhibits extremely high catalytic activity and stability toward the one-pot Knoevenagel condensation-hydrogenation reaction. Furthermore, the oriented NDHPC@mSiO manifests a boosted capacity and cycling stability in Li-S batteries compared to the counterpart that directly pyrolyzes without silica protection. This report provides an effective strategy of fabricating hierarchically oriented carbon composites for catalysis and energy storage applications.
碳基纳米材料因其迷人的特性而在催化和能源相关领域得到广泛应用。然而，由于在高温合成过程中生成的碳颗粒不可避免地聚集/融合，可控合成具有精细形态的多孔碳仍然是一项艰巨的挑战。在此，通过同时利用受限热解策略和金属有机框架（MOF）内不同的键合环境，制备了一种分级取向的碳结构（纤维状）复合材料。在所得复合材料中，取向碳提供了快速的质量（分子/离子/电子）转移效率；掺杂的N原子可以锚定或充当活性位点；介孔SiO（mSiO）壳不仅有效地防止衍生的碳或活性金属纳米颗粒（NP）聚集或浸出，而且在锂硫电池中充当“多硫化物储存库”以抑制“穿梭”效应。得益于这些优点，合成的复合材料Pd@NDHPC@mSiO（NDHPC表示N掺杂的分级多孔碳）对一锅法Knoevenagel缩合-氢化反应表现出极高的催化活性和稳定性。此外，与没有二氧化硅保护直接热解的对应物相比，取向的NDHPC@mSiO在锂硫电池中表现出更高的容量和循环稳定性。本报告提供了一种制备用于催化和储能应用的分级取向碳复合材料的有效策略。
