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71.
Kunpeng Zhao Haozhi Duan Nunna Raghavendra Pengfei Qiu Yi Zeng Jihui Yang Xun Shi Lidong Chen 《Advanced materials (Deerfield Beach, Fla.)》2017,29(42)
High‐performance thermoelectric materials require ultralow lattice thermal conductivity typically through either shortening the phonon mean free path or reducing the specific heat. Beyond these two approaches, a new unique, simple, yet ultrafast solid‐state explosive reaction is proposed to fabricate nanoporous bulk thermoelectric materials with well‐controlled pore sizes and distributions to suppress thermal conductivity. By investigating a wide variety of functional materials, general criteria for solid‐state explosive reactions are built upon both thermodynamics and kinetics, and then successfully used to tailor material's microstructures and porosity. A drastic decrease in lattice thermal conductivity down below the minimum value of the fully densified materials and enhancement in thermoelectric figure of merit are achieved in porous bulk materials. This work demonstrates that controlling materials' porosity is a very effective strategy and is easy to be combined with other approaches for optimizing thermoelectric performance. 相似文献
72.
Dechao Chen Shoucong Ning Jiao Lan Ming Peng Huigao Duan Anlian Pan Yongwen Tan 《Advanced materials (Deerfield Beach, Fla.)》2020,32(46):2004055
Although 2D layered metal compounds are widely exploited using various techniques such as exfoliation and vapor-phase-assisted growth, it is still challenging to construct the 2D materials in a 3D configuration with preservation of the unique physicochemical properties of the metal compounds. Herein, a general synthetic strategy is reported for a wide variety of 2D (atomic-scale thickness) metal compounds with 3D bicontinous nanoporous structure. 19 binary compounds including sulfides, selenides, tellurides, carbides, and nitrides, and five alloyed compounds, are successfully prepared via a surface alloy strategy, which are readily created by using a recyclable nanoporous gold assisted chemical vapor deposition process. These 3D nanoporous metal compounds with preserved 2D physicochemical properties, tunable pore sizes, and compositions for electrocatalytic applications, show excellent catalytic performance in the electrochemical N2 reduction reaction. This work opens up a promising avenue for fundamental studies and potential applications of a wide variety of nanoporous metal compounds. 相似文献
73.
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
74.
Gang Huang Jiuhui Han Fan Zhang Ziqian Wang Hamzeh Kashani Kentaro Watanabe Mingwei Chen 《Advanced materials (Deerfield Beach, Fla.)》2019,31(2)
The key bottlenecks hindering the practical implementations of lithium‐metal anodes in high‐energy‐density rechargeable batteries are the uncontrolled dendrite growth and infinite volume changes during charging and discharging, which lead to short lifespan and catastrophic safety hazards. In principle, these problems can be mitigated or even solved by loading lithium into a high‐surface‐area, conductive, and lithiophilic porous scaffold. However, a suitable material that can synchronously host a large loading amount of lithium and endure a large current density has not been achieved. Here, a lithiophilic 3D nanoporous nitrogen‐doped graphene as the sought‐after scaffold material for lithium anodes is reported. The high surface area, large porosity, and high conductivity of the nanoporous graphene concede not only dendrite‐free stripping/plating but also abundant open space accommodating volume fluctuations of lithium. This ingenious scaffold endows the lithium composite anode with a long‐term cycling stability and ultrahigh rate capability, significantly improving the charge storage performance of high‐energy‐density rechargeable lithium batteries. 相似文献
75.
76.
利用湿化学法,并采取逐步加热脱除沉淀中四氢呋喃分子的方式,制备具有高离子电导率和低活化能的纳米多孔β-Li 3PS 4固态电解质。利用同步热分析、X射线衍射、扫描电镜、拉曼光谱、氮气吸脱附和交流阻抗测试等手段研究不同处理阶段产物的形貌、结构和物相组成,并测试分析β-Li 3PS 4固态电解质的电化学性能。结果表明:采用该方法制备的纳米多孔β-Li 3PS 4固态电解质比表面积为 28.3m 2·g -1 ,平均孔径约23nm,电化学测试表明该电解质在20℃下的离子电导率为1.84×10 -4 S·cm -1 ,活化能为0.343eV,电子电导率为1.3×10 -8 S·cm -1 ,具有优异的电化学稳定性,与金属锂负极也具有良好的兼容性。 相似文献
77.
Metal–organic frameworks (MOFs) are crystalline coordination polymers, assembled from inorganic nodes connected by organic linker molecules. An enormous surface area, huge compositional variety, regular structure, and favorable mechanical properties are among their outstanding properties. Monolithic MOF thin films, i.e., surface‐mounted metal–organic frameworks (SURMOFs), with high degree of structural order and adjustable defect density, can be prepared on solid substrates using layer‐by‐layer techniques. Recent studies where SURMOFs served as model systems for quantitative studies of molecular interactions in porous media, including diffusion, are reviewed. Moreover, SURMOFs are ideally suited for the incorporation of photoactive molecules as well as to study electrical transport through crystalline molecular assemblies. Recent work has demonstrated that the realization of crystalline chromophore assemblies via the SURMOF approach allows the study of fundamental aspects of exciton transport, exciton channeling, and photon upconversion at internal interfaces in organic semiconductor materials. Due to their crystalline nature, MOF materials are well suited for quantitative comparisons with theoretical results; especially, since defect densities and types can be characterized and varied in a straightforward fashion. The active role of these nanoporous films in advanced applications, like for remote‐controlled release of molecules, membranes with photoswitchable selectivity, and ion‐conductors with adjustable conductivity, are also emphasized. 相似文献
78.
Hua‐Jun Qiu Peng Du Kailong Hu Jiaojiao Gao Huanglong Li Pan Liu Toshiaki Ina Koji Ohara Yoshikazu Ito Mingwei Chen 《Advanced materials (Deerfield Beach, Fla.)》2019,31(19)
Developing bifunctional electrocatalysts with high activities and long durability for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial toward the practical implementation of rechargeable metal–air batteries. Here, a 3D nanoporous graphene (np‐graphene) doped with both N and Ni single atoms/clusters is reported. The predoping of N by chemical vapor deposition (CVD) dramatically increases the Ni doping amount and stability. The resulting N and Ni codoped np‐graphene has excellent electrocatalytic activities for both the ORR and the OER in alkaline aqueous solutions. The synergetic effects of N and Ni dopants are revealed by density functional theory calculations. The free‐standing Ni,N codoped 3D np‐graphene shows great potential as an economical catalyst/electrode for metal–air batteries. 相似文献
79.
Kailong Hu Tingting Yu Yanyi Zhang Xiaorong Lin Yilu Zhao Guoqiang Xie Xingjun Liu Xi Lin Jun-ichi Fujita Hua-Jun Qiu Yoshikazu Ito 《Advanced functional materials》2021,31(38):2103632
Catalyzing oxygen reduction reaction (ORR) and accelerating oxygen diffusion are two key challenges for the requirements of the cathode catalysts in the metal-air batteries. A promising strategy for improving both ORR performance and mass diffusion simultaneously is to build carbon-based catalysts with ORR-active chemical dopants and 3D interconnected porosity. Herein, a 3D nanoporous N-doped carbon with bicontinuous porosity and interconnected open-pore channels is reported, which is prepared by a polyaniline-assisted template method. The polyaniline can efficiently inhibit the surface diffusion-caused template coarsening, achieving a small pore size of 35 nm. The small porous morphology gives rise to a high N-dopant concentration up to 7.20 at.%, which in turn exhibits a commercial Pt/C-comparable ORR performance together with satisfied durability in alkaline media. Using these nanoporous carbon catalysts as air electrodes, an all-solid-state flexible Al-air battery is assembled with the measured maximum power density reaching 130.5 mW cm−2, as compared to 106.2 mW cm−2 when the commercial Pt/C standard is used. This study provides an efficient method to synthesize 3D N-doped carbon with bicontinuous nano-sized pore channels for wide-ranging applications in portable and flexible devices. 相似文献
80.
Solution‐Processed Nanoporous Organic Semiconductor Thin Films: Toward Health and Environmental Monitoring of Volatile Markers 下载免费PDF全文
Fengjiao Zhang Ge Qu Erfan Mohammadi Jianguo Mei Ying Diao 《Advanced functional materials》2017,27(23)
Porous materials are ubiquitous in nature and have found a wide range of applications because of their unique absorption, optical, mechanical, and catalytic properties. Large surface‐area‐to‐volume ratio is deemed a key factor contributing to their catalytic properties. Here, it is shown that introducing tunable nanopores (50–700 nm) to organic semiconductor thin films enhances their reactivity with volatile organic compounds by up to an order of magnitude, while the surface‐area‐to‐volume ratio is almost unchanged. Mechanistic investigations show that nanopores grant direct access to the highly reactive sites otherwise buried in the conductive channel of the transistor. The high reactivity of nanoporous organic field‐effect transistors leads to unprecedented ultrasensitive, ultrafast, selective chemical sensing below the 1 ppb level on a hundred millisecond time scale, enabling a wide range of health and environmental applications. Flexible sensor chip for monitoring breath ammonia is further demonstrated; this is a potential biomarker for chronic kidney disease. 相似文献