摘要:
Ce-based organic framework materials [UIO-66(Ce)] were prepared, and the UIO-66(Ce)/ ZnCdS composite was attained by microwave irradiation. Moreover, the photocatalytic hydrogen production activity was evaluated. The experimental results revealed that the ZnCdS nanoparticle was decorated on the surface of UIO-66(Ce), and the hydrogen production ability of ZnCdS nanoparticle was improved by UIO-66(Ce) significantly. The hydrogen production yield of UIO-66(Ce)/ZnCdS reaches 3.958 mmol/g$h, in which is as about 1.95 times as that of ZnCdS (2.031 mmol/g$h). The improvement for photocatalytic hydrogen production yield is because UIO-66(Ce) can facilitate the photoinduced carriers to separating. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
通讯机构:
[Hong-Guang Jin; Zi-Sheng Chao] S;School of Materials Science and Engineering, Changsha University of Science & Technology, Changsha, 410114, China<&wdkj&>School of Materials Science and Engineering, Changsha University of Science & Technology, Changsha, 410114, China
摘要:
Cerium(IV)-based metal-organic frameworks (MOFs) have gained a growing attention in both scientific and industrial spheres due to their unique potential in fields such as redox catalysis and photocatalysis. However, the synthetic pathways of Ce(IV)-MOFs are still extremely dominated by the conventional solvothermal conditions. Meanwhile, the research on photocatalysis of Ce(IV)-MOFs is still in its infancy, more experimental evidence is highly desirable to accelerate the development of this field. Here we present an innovative, widespread, green and sustainable synthetic route for nanocrystalline Ce(IV)-MOFs with the UiO-66 structure. Seven Ce-UiO-66-MOFs were successfully prepared at room temperature using water as the sole solvent in the presence of sodium acetate (NaAc). Furthermore, the photocatalytic activities of these Ce(IV)-MOFs for decarboxylative oxygenation of 4-fluorophenylacetic acid to give corresponding C-O bond-forming products 4-fluorobenzaldehyde and 4-fluorobenzyl alcohol under blue light-emitting diodes (LEDs) irradiation and air were studied. Control experiments revealed that Ce-UiO-66-BDC exhibited the optimized catalytic efficiency among these Ce (IV)-MOFs, and can be applied to various arylacetic acids.
摘要:
Dense Si3N4 ceramics were prepared by fused deposition molding method accompanied by gas pressure sintering. In this study, the surface steps, inter layer bonding and microstructure evolution were characterized and dense Si3N4 ceramics without obvious defects were obtained. It was verified that layer thickness and nozzle diameter have little impact on the density and flexural strength of both green and sintered parts. As to the filling strategy, contour offset path was more effective to obtain sintered part with higher flexural strength than parallel lines and grid path, which was due to the possible voids appeared at the intersection of print paths with different di-rections. The highest flexure strength 824.74 +/- 85 MPa was obtained with layer thickness 0.15 mm, nozzle size 0.6 mm and contour offset path. The reliability of the obtained Si3N4 ceramics was also investigated and complex shaped Si3N4 ceramic parts with good shape keeping was prepared successfully.
通讯作者:
Mei Ding<&wdkj&>Xiaobo Zhu<&wdkj&>Chuankun Jia
作者机构:
[Xuechun Lou; Hu Fu; Jian Xu; Yong Long; Su Yan; Haitao Zou; Bo Lu; Murong He; Xiaobo Zhu] College of Materials Science and Engineering, Changsha University of Science & Technology, Changsha 410114, China;National Engineering Laboratory of Highway Maintenance Technology, School of Traffic & Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China;[Mei Ding; Chuankun Jia] College of Materials Science and Engineering, Changsha University of Science & Technology, Changsha 410114, China<&wdkj&>National Engineering Laboratory of Highway Maintenance Technology, School of Traffic & Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China
摘要:
Based on inexpensive, safe, and environmentally friendly active redox species, neutral polysulfide-ferrocyanide redox flow batteries (PFRFBs) have attracted much attention for large-scale energy storage. However, the development of PFRFBs is undermined by the expensive commercial membrane materials as well as the sluggish polysulfide redox reactions. This work attempts to solve these critical problems by combining the economical membrane with the highly catalytic electrode. In specific, K+-exchanged sulfonated polyether ether ketone (SPEEK-K) membranes have been investigated in PFRFBs to replace the costly Nafion membrane. SPEEK-K with optimized degree of sulfonation enables the PFRFB high average coulombic efficiency of 99.80% and superior energy efficiency of 90.42% at a current density of 20 mA cm-2. Meanwhile, to overcome the kinetic limitations of polysulfide redox reactions, a CuS-modified carbon felt electrode is demonstrated with excellent catalytic performance, enabling the PFRFB higher and more stable energy efficiency over cycling. The combination of the cost-effective membrane with the catalytic electrode in one cell leads to a capacity retention of 99.54% after 1180 cycles and an outstanding power density (up to 223 mW cm-2). The significant enhancements of electrochemical performance at reduced capital cost will make the PFRFB more promising for large-scale energy storage systems.
摘要:
Along with the surging demand for of rechargeable alkali-ion (Li+, Na+, or K+) batteries, the cost and availability of the battery materials become critical. In this paper, we report the use of spent asphalt, which is widely available and even poses environmental risks, to produce a high-performing universal Li/Na/K-ion host material. Taking advantage of a the nano-Fe2O3 template, the spent asphalt is converted into mesoporous carbon with an interconnected three-dimensional porous structure, high surface area, and numerous rich crystal defects. As an anode material for Li-ion batteries, the mesoporous carbon exhibits a reversible capability of 674.2 mA h g(-1) at 0.2 A g(-1) as well as excellent rate and cycling performance (258.7 mA h g(-1) at 1.0 A g(-1) after 1000 cycles) owing to the shortened diffusion path of ion and easier penetration of electrolytes. The carbon anode also delivers superior reversible capacities and cycling stability in Na-ion and K-ion batteries. With the potential to simul-taneously tackle energy and environmental problems, the spent asphalt-derived mesoporous carbon is promising for large-scale applications.
摘要:
采用电镀和水热反应两步法制备了一种高柔性Ni Te/Ni@CC超级电容器正极材料。利用X射线衍射、扫描电镜、能谱仪和电化学工作站对Ni Te/Ni@CC电极进行了表征与分析。结果表明,该电极具有CC-Ni-Ni Te的层次结构;在电流密度为5 m A/cm~2时,电极的面积比电容达到2.85 F/cm~2;由该电极组装的Ni Te/Ni@CC//AC/CC全固态柔性超级电容器在5.57 m W/cm~2的面功率密度下可提供高达0.50 m W·h/cm~2的面能量密度,并且在0~90°的2 000次弯曲循环后,具有77.20%的初始电容保持率。
关键词:
energy harvesting;energy harvesting;interaction;interaction;Internet of Things (IoT);Internet of Things (IoT);P-TENGs;P-TENGs;paper-based sensors;paper-based sensors;self-powered devices;self-powered devices;triboelectric nanogenerator;triboelectric nanogenerator
关键词:
3D Ni3Se2 nano-Architectures;Electrochemical performances;Supercapacitor;Electrochemical activity
摘要:
The multifunctional 3D Ni3Se2 nano-architectures were successfully synthesized by a facile solvothermal route, and their electrochemical performances were systematically investigated. As electrode for supercapacitor, 3D Ni3Se2 nano-architectures exhibited a high specific capacity of 1545.6 mu Ah cm(-2), good rate capability and excellent cycling stability. Besides, as the electrodes for hydrogen evolution and oxygen evolution reactions, 3D Ni3Se2 nano-architectures demonstrated electrochemical activity and stability towards water splitting. Moreover, the electrocatalytic behaviors of the nanostructures were also investigated at various temperatures. Remarkably, as an electrolyzer for overall water splitting, 3D Ni3Se2 nano-architectures showed low cell voltages of 1.61 V for anode and -1.75 V for cathode at 10 mA cm(-2) and stability for 10 h. The work presented here sheds some light on the development of low-cost and high-activity multifunctional electrode materials for electrochemical energy storage and conversion. (C) 2020 Elsevier B.V. All rights reserved.
通讯机构:
[Chuansheng Chen] C;College of Materials Science and Engineering, School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha 410114, People*s Republic of China
摘要:
Sn-doping ZnMn2O4 (Sn-ZMO) porous microspheres with shell structure were synthesized by utilizing SnO as Sn source. The effect of Sn content on its structure, morphology, and performance was investigated. Sn doping can increase the crystal plane spacing of ZnMn2O4 (ZMO) microspheres and enhance the electrochemical performance of ZMO materialis. When the Sn-doping content is 0.5%, the specific capacitance of Sn-ZMO microspheres is 18.5% higher than that of pure ZMO microsphere, which reaches 530 F/g under the current density of 1 A/g. Furthermore, the cycle stability has a significant promotion. 77% of the capacity is maintained after 2000 cycles under the scan rate of 20 mV/s. The enhancement in electrochemical performance is attributed to form a spherical shell with a certain thickness after ZMO microsphere were doped by Sn atom, in which the spherical shell can suppresses the volume expansion during the charge-discharge process. (C) 2021 Elsevier B.V. All rights reserved.
期刊:
Colloids and Surfaces A: Physicochemical and Engineering Aspects,2021年628:127230 ISSN:0927-7757
通讯作者:
Fan, Jincheng(fanjincheng2009@163.com)
作者机构:
[Cui, Kexin; Fan, Jincheng; Li, Songyang; Li, Shidong; Khadidja, Moukaila Fatiya; Wu, Jianghong; Jin, Hong-Guang; Chao, Zisheng] Changsha Univ Sci & Technol, Coll Mat Sci & Engn, Changsha 410114, Hunan, Peoples R China.;[Wu, Jianghong] Shenzhen Technol Univ, Coll Hlth Sci & Environm Engn, Shenzhen 518118, Guangdong, Peoples R China.;[Zeng, Wengao] Xi An Jiao Tong Univ, Int Res Ctr Renewable Energy, State Key Lab Multiphase Flow Power Engn, Xian 710049, Peoples R China.;[Wei, Huige] Tianjin Univ Sci & Technol, Coll Chem Engn & Mat Sci, Tianjin Key Lab Brine Chem Engn & Resource Ecouti, Tianjin 300457, Peoples R China.;[Naik, Nithesh] Manipal Acad Higher Educ, Manipal Inst Technol, Dept Mech & Mfg Engn, Manipal 576104, Karnataka, India.
通讯机构:
[Jincheng Fan; Zisheng Chao] C;[Huige Wei] T;[Zhanhu Guo] I;College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China<&wdkj&>Tianjin Key Laboratory of Brine Chemical Engineering and Resource Ecoutilization, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, 300457, China<&wdkj&>College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China<&wdkj&>Integrated Composites Laboratory (ICL), Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA
摘要:
Currently,Na-ion battery(NIB) has become one of the most potential alternatives for Li-ion batteries due to the safety and low cost.As a promising anode for Na-ion storage,expanded graphite has attracted considerable attention.However,the sodiation-desodiation process is still unclear.In our work,we obtain expanded graphite through slight modified Hummer’s method and subsequent thermal treatment,which exhibits excellent cycling stability.Even at a high current density of 1 A g-1,our expanded graphite still remains a high reversible capacity of 100 mA h g-1 after 2600 cycles.Furthermore,we also investigate the electrochemical mechanism of our expanded graphite for Na-ion storage by operando Raman technique,which illuminate the electrochemical reaction during different sodiation-desodiation processes.
摘要:
Nanostructured iron sulfides are regarded as a potential anode material for sodium-ion batteries in virtue of the rich natural abundance and remarkable theoretical capacity.However,poor rate performance and inferior cycling stability caused by sluggish kinetics and volume swelling represent two main obstacles at present. The previous research mainly focuses on nanostructure design and/or hybridizing with conductive materials.Further boosting the property by adjusting Fe/S atomic ratio in iron sulfides is rarely reported.In this work,Fe7 S8 and FeS2 encapsulated in N-doped hollow carbon fibers(NHCFs/Fe7 S8 and NHCFs/FeS2) are constructed by a combined chemical bath deposition and subsequent sulfidation treatment.The well-designed NHCFs/Fe7 S8 electrode displays a remarkable capacity of 517 mAh g-1 at 2 A g-1after 1000 cycles and a superb rate capability with a capability of 444 mAh g-1 even at 20 A g-1 in etherbased electrolyte.Additionally,the rate capability of NHCFs/Fe7 S8 is superior to that of the contrast NHCFs/FeS2 electrode and also much better than the values of the most previously reported iron sulfide-based anodes.The in-depth mechanism explanation is explained by further experimental analysis and theoretical calculation,revealing Fe7 S8 displays improved intrinsic electronic conductivity and faster Na+ diffusion coefficient as well as higher reaction reversibility.
摘要:
The alumina slurry with high solid content was prepared, and a rapid lamination route for fabricate the NextelTM 610 fiber reinforced alumina composite was proposed in this work. The microstructure and mechanical properties of the as-received all-oxide composite were investigated by a series of techniques. The shrinkage cracks in matrix were reduced, while porous structure in composite was maintained. The N610/alumina composite has weak matrix and weak interface, as the Young's modulus of the alumina matrix and the interfacial shear strength of the composite are 140.8 +/- 2.5GPa and 129.1 +/- 14.6MPa. The mechanical properties of the composite are much higher than lots of oxide/oxide composites, given its flexural strength, interlaminar shear strength and the fracture toughness are 398.4 +/- 5.7MPa.27.0 +/- 0.5MPa and 14.1 +/- 0.9MPa.m1/2, respectively. The flexural strength of the virgin composite keep stable at 25-1050 degrees C, while dramatically decrease at 1100-1200 degrees C.