CATALYSIS TODAY
·
2018
·
IF 4.667
Xintong Zhou,Chang-jun Liu
Structured porous carbon materials have been extensively applied for catalyst, sensor, adsorbent, energy storage materials and many others. However, the preparation of such carbon materials in a controllable way remains a significant challenge. In this work, 3D printing has been employed to prepare porous carbon structures with tailorable pore sizes. A starch/gelatin ink has been applied as carbon source with SiO 2 monodispersed spheres as hard template. The process exhibits an excellent printing accuracy. Controllable meso and macro structures can be thereby obtained. The printed monolithic structures have been used as metal-free catalysts for the selective oxidation of benzyl alcohol, as an illustration. The monolithic and meso/macro-porous structure has a remarkable influence on the reaction rate. A high conversion with high benzaldehyde selectivity has been achieved. The 3D printing strategy provides us a simple, low cost and reliable way of fabricating carbon structures with designable meso/macro-pores, which is promising for many other applications beyond catalysis.
研究领域:
材料科学
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催化化学
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能源材料
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纳米结构材料
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功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Bin Qin,Yifei Cai,Xiaoqing Si,Chun Li,Jian Cao,Weidong Fei,Junlei Qi
The practical application of lithium-sulfur (Li-S) batteries is impeded by the shuttle effect of intermediate polysulfides and the inherent sluggish kinetics. Herein, Mo 2 C nanocatalysts anchoring on holey graphene scaffold (Mo 2 C@HGr) is explored as a lightweight and ultrathin modified separator to conquer the above issues. The artificially customized holes on holey graphene sheets facilitate ionic transfer and electrolyte penetration, and further enhance the sulfur utilization under lean electrolyte conditions. The experimental results together with theoretic calculation demonstrate the favourable chemical adsorption ability of Mo 2 C sites that blocking the diffusion of LiPSs. Abundant triple-phase interfaces among Mo 2 C nanomediators, holey graphene and electrolyte boost the conversion kinetics of the intercepted LiPSs. As a result, the cell with Mo 2 C@HGr modified separator shows superior rate capability (836 mAh g −1 ) even at 5 C current with a negligible Mo 2 C@HGr loading of 0.08 mg cm −2 . Furthermore, ultrahigh areal capacity of 5.9 mAh cm −2 is still attained with high sulfur loading of 6 mg cm −2 under lean electrolyte operation (E/S = 5.6 µL mg −1 ). This design concept can be extended to other graphene based multifunctional nanocomposite toward the development of more practical Li-S batteries.
研究领域:
电化学
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能源材料
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纳米催化
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电池技术
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功能复合材料
✓ 已验证
DOI
高影响因子
OPTICS AND LASER TECHNOLOGY
·
2023
·
IF 5
Shizhou Tan,Pengcheng Jian,Maocheng Shan,Yongming Zhao,Zhihua Zheng,Yiming Yang,Yuhui Zeng,Dan Xu,Zhenyu Chen,Changqing Chen,Feng Wu,Jiangnan Dai
In this work, we demonstrated tunable structured AlGaN-based nanoporous (NP) distributed Bragg reflectors (DBRs) with high-reflectivity through one-step vertical-lateral electrochemical etching (ECE). The aperture of nanopores in the doping layer and the size and density of V-pits on the surface of NP-DBRs can be tuned by controlling the etching bias. Furthermore, by further tuning the thickness of alternating layers, we achieved high reflectivity of NP-DBRs at multiple center wavelengths within the wavelength range from 280 to 800 nm. To explore its potential applications, MoS 2 with a photoluminescence (PL) emission in the red light region was grown for the first time on the NP-DBRs. Due to the light localized effect of surface V-pits and the high reflectivity of the bottom DBRs , the PL intensity of MoS 2 was significantly enhanced by a factor of 37.3 compared to the region without NP-DBRs. The PL enhancement of MoS 2 on porous AlGaN and different periodic NP-DBRs further validated the PL enhancement mechanism. The corresponding theoretical simulations also revealed that the PL enhancement should be attributed to the combined effect of enhanced light absorption and NP-DBRs induced emission interference. The fabricated AlGaN-based NP-DBRs provide a new approach for improving the quantum efficiency of two-dimensional layered materials, which holds significant importance for advancing the development of miniaturized and integrated 2D/3D heterogeneous structure systems in the field of optoelectronics.
研究领域:
光电子学
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半导体材料
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纳米光子学
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二维材料
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固体物理
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表面科学
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集成光子器件
✓ 已验证
DOI
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 34
·15881-15891
·
IF 6.97
Yong Xu,Jun Chen,Ze'en Xiao,Caixia Ou,Weixia Lv,Lihong Tao,Shengwen Zhong
A porous composite electrode composed of diatomite-mixed 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) is prepared by electrostatic spinning technology. Compared with traditional coated electrodes without diatomite mixing, the obtained composite electrode materials have higher porosity, larger specific surface area and faster lithium ion transport channels, which makes them exhibit better electrochemical performance, such as smaller impedance, higher capacity, and better cycling stability and rate performance. The electrospun diatomite-mixed 1,4,5,8-NTCDA composite (ED-1,4,5,8-NTCDA) electrode shows an initial coulombic efficiency of 77.2%, which is much higher than that of the electrospun 1,4,5,8-NTCA (E-1,4,5,8-NTCDA) electrode without diatomite mixing (63.8%) and the coated 1,4,5,8-NTCA (C-1,4,5,8-NTCDA) electrode (48.3%). Moreover, the ED-1,4,5,8-NTCDA electrode displays an initial discharge capacity of 1106.5 mA h g−1, which is much higher than that of the E-1,4,5,8-NTCDA electrode (546.0 mA h g−1) and the C-1,4,5,8-NTCDA electrode (185.4 mA h g−1). After 200 cycles, the capacity of the ED-1,4,5,8-NTCDA electrode remains at 1008.5 mA h g−1 with a retention ratio of 91.2%, which is also much higher than that of 753.2 mA h g−1 for the E-1,4,5,8-NTCDA electrode and 288.1 mA h g−1 for the C-1,4,5,8-NTCDA electrode. Even at a higher current density of 1500 mA g−1, its capacity remains above 508.9 mA h g−1. The ED-1,4,5,8-NTCDA electrode presents superior performance, which opens up a promising new approach for further utilization of organic materials as electrode materials in rechargeable lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2018
·Vol. 25
·期 10
·5807-5819
·
IF 3.809
Sun Zhuangzhi,Du Shanqi,Li Fei,Yang Lu,Zhang Dan,Song Wenlong
A nanocomposite soft actuator based on porous high-conductivity electrode membrane, which was composed of biopolymer cellulose mixed with chitosan and highly conductive nanoparticles generated by reduced graphene oxide encapsulated multi-walled carbon nanotube, was developed in this paper. No new substance was discovered in the regenerated electrode layer through the scanning analysis from FT-IR and XRD. Actuators exhibited significant enhancement in peak to peak displacement, which was 3.64 times increased than the traditional value at 5 V 0.1 Hz. With the test of solid-state electric double layer capacitor, actuators showed the highest specific capacitance (10.695 F g −1 ) at the current density of 1 A g −1 , the lowest internal resistance (9.2 Ω g −1 ) in the frequency range of 10 5 –10 −2 Hz, and the lowest energy density (901 Wh kg −1 ) at the current density of 10 A g −1 , which demonstrated the absolute advantages in the conductivity and channels for electrons. These findings suggest that research on porous high-conductivity electrode layer holds great promise in the further study of higher performance actuators.
研究领域:
生物材料学
·
纳米医学
·
组织工程
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柔性电子学
·
生物力学
·
智能驱动系统
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）