共查询到20条相似文献,搜索用时 0 毫秒
1.
Kun Gao Bin Wang Li Tao Benjamin V. Cunning Zhipan Zhang Shuangyin Wang Rodney S. Ruoff Liangti Qu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(13)
N‐doped carbon nanomaterials have rapidly grown as the most important metal‐free catalysts in a wide range of chemical and electrochemical reactions. This current report summarizes the latest advances in N‐doped carbon electrocatalysts prepared by N mono‐doping and co‐doping with other heteroatoms. The structure–performance relationship of these materials is subsequently rationalized and perspectives on developing more efficient and sustainable electrocatalysts from carbon nanomaterials are also suggested. 相似文献
2.
Xiaoguang Duan Kane O'Donnell Hongqi Sun Yuxian Wang Shaobin Wang 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(25):3036-3044
Sulfur and nitrogen co‐doped reduced graphene oxide (rGO) is synthesized by a facile method and demonstrated remarkably enhanced activities in metal‐free activation of peroxymonosulfate (PMS) for catalytic oxidation of phenol. Based on first‐order kinetic model, S–N co‐doped rGO (SNG) presents an apparent reaction rate constant of 0.043 ± 0.002 min?1, which is 86.6, 22.8, 19.7, and 4.5‐fold as high as that over graphene oxide (GO), rGO, S‐doped rGO (S‐rGO), and N‐doped rGO (N‐rGO), respectively. A variety of characterization techniques and density functional theory calculations are employed to investigate the synergistic effect of sulfur and nitrogen co‐doping. Co‐doping of rGO at an optimal sulfur loading can effectively break the inertness of carbon systems, activate the sp2‐hybridized carbon lattice and facilitate the electron transfer from covalent graphene sheets for PMS activation. Moreover, both electron paramagnetic resonance (EPR) spectroscopy and classical quenching tests are employed to investigate the generation and evolution of reactive radicals on the SNG sample for phenol catalytic oxidation. This study presents a novel metal‐free catalyst for green remediation of organic pollutants in water. 相似文献
3.
4.
Co‐N‐Doped Mesoporous Carbon Hollow Spheres as Highly Efficient Electrocatalysts for Oxygen Reduction Reaction 下载免费PDF全文
Feng Hu Hongchao Yang Changhong Wang Yejun Zhang Huan Lu Qiangbin Wang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(3)
Rational design of cost‐effective, nonprecious metal‐based catalysts with desirable oxygen reduction reaction (ORR) performance is extremely important for future fuel cell commercialization, etc. Herein, a new type of ORR catalyst of Co‐N‐doped mesoporous carbon hollow sphere (Co‐N‐mC) was developed by pyrolysis from elaborately fabricated polystyrene@polydopamine‐Co precursors. The obtained catalysts with active Co sites distributed in highly graphitized mesoporous N‐doped carbon hollow spheres exhibited outstanding ORR activity with an onset potential of 0.940 V, a half‐wave potential of 0.851 V, and a small Tafel slope of 45 mV decade?1 in 0.1 m KOH solution, which was comparable to that of the Pt/C catalyst (20%, Alfa). More importantly, they showed superior durability with little current decline (less than 4%) in the chronoamperometric evaluation over 60 000 s. These features make the Co‐N‐mC one of the best nonprecious‐metal catalysts to date for ORR in alkaline condition. 相似文献
5.
Hyungkyu Han Frantisek Karlicky Sudhagar Pitchaimuthu Sun Hae Ra Shin Aiping Chen 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(40)
In spite of having several advantages such as low cost, high chemical stability, and environmentally safe and benign synthetic as well as operational procedures, the full potential of carbon dots (CDs) is yet to be explored as photosensitizers due to the challenges associated with the fabrication of well‐arrayed CDs with many other photocatalytic heterostructures. In the present study, a unique combination of metal–organic framework (MOF)‐decorated zinc oxide (ZnO) 1D nanostructures as host and CDs as guest species are explored on account of their potential application in photoelectrochemical (PEC) water splitting performance. The synthetic strategy to incorporate well‐defined nitrogen‐doped carbon dots (N‐CDs) arrays onto a zeolitic imidazolate framework‐8 (ZIF‐8) anchored on ZnO 1D nanostructures allows a facile unification of different components which subsequently plays a decisive role in improving the material's PEC water splitting performance. Simple extension of such strategies is expected to offer significant advantages for the preparation of CD‐based heterostructures for photo(electro)catalytics and other related applications. 相似文献
6.
7.
8.
Xue Feng Lu Le Yu Jintao Zhang Xiong Wen Lou 《Advanced materials (Deerfield Beach, Fla.)》2019,31(30)
Designing novel non‐noble electrocatalysts with controlled structures and composition remains a great challenge for efficient hydrogen evolution reaction (HER). Herein, a rational synthesis of ultrafine carbide nanocrystals confined in porous nitrogen‐doped carbon dodecahedrons (PNCDs) by annealing functional zeolitic imidazolate framework (ZIF‐8) with molybdate or tungstate is reported. By controlling the substitution amount of MO4 units (M = Mo or W) in the ZIF‐8 framework, dual‐phase carbide nanocrystals confined in PNCDs (denoted as MC‐M2C/PNCDs) can be obtained, which exhibit superior activity toward the HER to the single‐phased MC/PNCDs and M2C/PNCDs. The evenly distributed ultrafine nanocrystals favor the exposure of active sites. PNCDs as the support facilitate charge transfer and protect the nanocrystals from aggregation during the HER process. Moreover, the strong coupling interactions between MC and M2C provide beneficial sites for both water dissociation and hydrogen desorption. This work highlights a new feasible strategy to explore efficient electrocatalysts via engineering on nanostructure and composition. 相似文献
9.
Metal–organic framework (MOF) composites have recently been considered as promising precursors to derive advanced metal/carbon‐based materials for various energy‐related applications. Here, a dual‐MOF‐assisted pyrolysis approach is developed to synthesize Co–Fe alloy@N‐doped carbon hollow spheres. Novel core–shell architectures consisting of polystyrene cores and Co‐based MOF composite shells encapsulated with discrete Fe‐based MOF nanocrystallites are first synthesized, followed by a thermal treatment to prepare hollow composite materials composed of Co–Fe alloy nanoparticles homogeneously distributed in porous N‐doped carbon nanoshells. Benefitting from the unique structure and composition, the as‐derived Co–Fe alloy@N‐doped carbon hollow spheres exhibit enhanced electrocatalytic performance for oxygen reduction reaction. The present approach expands the toolbox for design and preparation of advanced MOF‐derived functional materials for diverse applications. 相似文献
10.
Rajib Paul Feng Du Liming Dai Yong Ding Zhong Lin Wang Fei Wei Ajit Roy 《Advanced materials (Deerfield Beach, Fla.)》2019,31(13)
Sustainable and cost‐effective energy generation has become crucial for fulfilling present energy requirements. For this purpose, the development of cheap, scalable, efficient, and reliable catalysts is essential. Carbon‐based heteroatom‐doped, 3D, and mesoporous electrodes are very promising as catalysts for electrochemical energy conversion and storage. Various carbon allotropes doped with a variety of heteroatoms can be utilized for cost‐effective mass production of electrode materials. 3D porous carbon electrodes provide multiple advantages, such as large surface area, maximized exposure to active sites, 3D conductive pathways for efficient electron transport, and porous channels to facilitate electrolyte diffusion. However, it is challenging to synthesize and functionalize isotropic 3D carbon structures. Here, various synthesis processes of 3D porous carbon materials are summarized to understand how their physical and chemical properties together with heteroatom doping dictate the electrochemical catalytic performance. Prospects of attractive 3D carbon structural materials for energy conversion and efficient integrated energy systems are also discussed. 相似文献
11.
Nitrogen‐Doped Porous Carbon Nanosheets Templated from g‐C3N4 as Metal‐Free Electrocatalysts for Efficient Oxygen Reduction Reaction 下载免费PDF全文
Huijun Yu Lu Shang Tong Bian Run Shi Geoffrey I. N. Waterhouse Yufei Zhao Chao Zhou Li‐Zhu Wu Chen‐Ho Tung Tierui Zhang 《Advanced materials (Deerfield Beach, Fla.)》2016,28(25):5080-5086
12.
13.
14.
15.
16.
Well‐Dispersed ZIF‐Derived Co,N‐Co‐doped Carbon Nanoframes through Mesoporous‐Silica‐Protected Calcination as Efficient Oxygen Reduction Electrocatalysts 下载免费PDF全文
Lu Shang Huijun Yu Xing Huang Tong Bian Run Shi Yufei Zhao Geoffrey I. N. Waterhouse Li‐Zhu Wu Chen‐Ho Tung Tierui Zhang 《Advanced materials (Deerfield Beach, Fla.)》2016,28(8):1668-1674
17.
18.
Xuelian Li Jingwen Zhou Junxiang Zhang Matthew Li Xuanxuan Bi Tongchao Liu Tao He Jianli Cheng Fan Zhang Yongpeng Li Xiaowei Mu Jun Lu Bin Wang 《Advanced materials (Deerfield Beach, Fla.)》2019,31(39)
The Li–CO2 battery is a promising energy storage device for wearable electronics due to its long discharge plateau, high energy density, and environmental friendliness. However, its utilization is largely hindered by poor cyclability and mechanical rigidity due to the lack of a flexible and durable catalyst electrode. Herein, flexible fiber‐shaped Li–CO2 batteries with ultralong cycle‐life, high rate capability, and large specific capacity are fabricated, employing bamboo‐like N‐doped carbon nanotube fiber (B‐NCNT) as flexible, durable metal‐free catalysts for both CO2 reduction and evolution reactions. Benefiting from high N‐doping with abundant pyridinic groups, rich defects, and active sites of the periodic bamboo‐like nodes, the fabricated Li–CO2 battery shows outstanding electrochemical performance with high full‐discharge capacity of 23 328 mAh g?1, high rate capability with a low potential gap up to 1.96 V at a current density of 1000 mA g?1, stability over 360 cycles, and good flexibility. Meanwhile, the bifunctional B‐NCNT is used as the counter electrode for a fiber‐shaped dye‐sensitized solar cell to fabricate a self‐powered fiber‐shaped Li–CO2 battery with overall photochemical–electric energy conversion efficiency of up to 4.6%. Along with a stable voltage output, this design demonstrates great adaptability and application potentiality in wearable electronics with a breath monitor as an example. 相似文献
19.
Sibo Wang Yan Wang Song Lin Zhang Shuang‐Quan Zang Xiong Wen Lou 《Advanced materials (Deerfield Beach, Fla.)》2019,31(41)
Ultrathin ZnIn2S4 nanosheets (NSs) are grown on Co/N‐doped graphitic carbon (NGC) nanocages, composed of Co nanoparticles surrounded by few‐layered NGC, to obtain hierarchical Co/NGC@ZnIn2S4 hollow heterostructures for photocatalytic H2 generation with visible light. The photoredox functions of discrete Co, conductive NGC, and ZnIn2S4 NSs are precisely combined into hierarchical composite cages possessing strongly hybridized shell and ultrathin layered substructures. Such structural and compositional virtues can expedite charge separation and mobility, offer large surface area and abundant reactive sites for water photosplitting. The Co/NGC@ZnIn2S4 photocatalyst exhibits outstanding H2 evolution activity (e.g., 11270 µmol h?1 g?1) and high stability without engaging any cocatalyst. 相似文献
20.
Carbon Nanoframes: Well‐Dispersed ZIF‐Derived Co,N‐Co‐doped Carbon Nanoframes through Mesoporous‐Silica‐Protected Calcination as Efficient Oxygen Reduction Electrocatalysts (Adv. Mater. 8/2016) 下载免费PDF全文
Lu Shang Huijun Yu Xing Huang Tong Bian Run Shi Yufei Zhao Geoffrey I. N. Waterhouse Li‐Zhu Wu Chen‐Ho Tung Tierui Zhang 《Advanced materials (Deerfield Beach, Fla.)》2016,28(8):1712-1712