INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Zhiyou Lian,Zhourong Xiao,Junjie Zhang,Xiangwen Zhang,Li Wang,Ji-Jun Zou,Guozhu Li
The sol-gel method produces supported nickel catalysts possessing good stability. However, the catalysts are plagued by the issue of severe nickel embedment, which limits the accessibility and utilization efficiency of active sites. To address this issue, hard template (e.g., CNTs and SBA-15) was added during the sol-gel synthesis of Ni/CeO 2 , and subsequently removed to optimize the accessibility and stability of Ni nanoparticles on ceria. This approach effectively adjusts the embedment, exposure, deficiency and dispersion of Ni nanoparticles on ceria, thus endows Ni/CeO 2 with high activity, high H 2 selectivity and good stability. As regulated by SBA-15, the Ni/CeO 2 catalyst possesses high specific surface area (128.9 m 2 /g), abundant oxygen defects, large surface nickel content (5.39%), and small nickel particle size (4.58 nm). The optimized Ni/CeO 2 catalyst achieved a methane conversion of 82% at 650 °C, under a methane GHSV of 10000 mL h −1 ·g cat −1 and a water/methane ratio of 2. Moreover, this activity is well maintained for 100 h without any deactivation.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2018
·
IF 2.943
Xu Xia,Jiwei Chen,Juan Shen,Di Huang,Peizhen Duan,Guohong Zou
Hydroxyapatite (HAp) with hollow structure was successfully synthesized by hydrothermal process of as-prepared calcium carbonate used as a hard template and calcium sources in a diammonium phosphate solution. Calcium carbonate was fabricated by precipitation, which possessed different morphologies such as balls, rods and blocks through regulating the amount of citric acid. The synthesized powders were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrograph (FT-IR), field-emission scanning electron microscope (FESEM) and high-resolution transmission electron microscopy (HRTEM) and nitrogen adsorption–desorption. Results indicated that different morphologies calcium carbonate could convert to hollow structural HAp with the higher BET surface area and the mesopores. Hydrothermal temperature and hydrothermal time play a slight role on transition percentage. As hydrothermal temperature and hydrothermal time increased, the conversion rate of calcium carbonate to hydroxyapatite increased. The possible formation mechanism of hydroxyapatite was preliminarily investigated. The resultants of HAp are interesting materials for drug delivery and sustained-release.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Caiyun Xu,Hongwei Yang,Zhizhong Xie,Dan Liu,Hua Zheng,Xi Li,Ruiming Zhang,Haolin Tang,Junsheng Li,Deyu Qu
The rapid growth in energy demands and environmental concerns have drawn great attention to the development of new functional materials for sustainable energy technologies. As an emerging material, mesoporous carbon-based materials exhibit unique properties and have been considered promising candidates for electrochemical hydrogen storage applications. However, pure mesoporous carbon as electrode material may suffer from sluggish electrolyte transportation kinetic and poor hydrophilicity. Two-dimensional layered structure with high exposure area and nitrogen doping, which provides the improved accessibility of ions as well as the hydrophilicity of carbon materials, can cope with these two challenges. Here, the nitrogen-doped layered mesoporous carbon sheets, prepared by the double-hard-template route, were characterized using various technologies and investigated the electrochemically stored hydrogen energy properties. The results exhibit that hydrogen storage can be achieved around 104 mAh g −1 at 100 mA g −1 , and the capacity retention was 85.4% at 2 A g −1 . Moreover, it also displays superior cycling stability with a retention of 98% upon 300 cycles. According to the obtained results, the layered mesoporous carbon sheets demonstrated suitable capacity as a potential and promising active material for hydrogen-proton-related devices.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2020
·
IF 4.605
Qiang Zhang,Yi Zhang,Sainan Liu,Huaming Yang
Halloysite nanotubes were investigated as a hard template for the preparation of multi-functional porous carbon due to their one-dimensional ordered structures and the composition of aluminosilicate . Herein, a novel N-doped three-dimensional porous carbon nanofiber (3D PCN) was obtained following electrospinning, pyrolysis and demineralization of natural halloysite. When used as anodes in Na + -batteries, the obtained 3D PCN exhibited a high specific capacity of 266 mAh·g −1 at a current density of 100 mA·g −1 and super cycling stability with a capacity retention of 91.1% after 5000 cycles at 1 A·g −1 . This work can not only extend the application of halloysite in energy storage but also provide a low-cost and promising three-dimensional porous carbon material for advanced Na + batteries .
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2018
·
IF 4.521
Shifu Wang,Zuoyi Xiao,Xiuping Ma,Zhenyu Zhao,Dongmei Guo,Yu Chen,Shangru Zhai,Qingda An,Dongjiang Yang
The development of a sustainable catalyst with high catalytic activity and easy recovery property is an important subject in the field of heterogeneous catalysis. In this work, we developed a hard template-induced internal solidification procedure for preparation of ultrafine metal nanoparticles (NPs) supported on GLA-PEI-CA beads. During the fabrication process, CaCO 3 NPs had a dual function, not only serviced as a hard template to adjust the structure of the as-prepared catalyst, but also as an indirect crosslinking agent to obtain hydrogel beads. The resulting beads were characterized using FT-IR, XRD, BET, SEM, TEM, EDS and XPS. The results revealed that Cu NPs with a narrow size distribution in 2–3 nm were uniformly immobilized on the surface of GLA-PEI-CA-1 beads with high specific surface area and well-developed hierarchical pore structure. As a result, the Cu@GLA-PEI-CA-1 beads exhibited remarkably catalytic activity and high stability, with more than 90% conversion within 10 successive cycles, towards the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH 4 in aqueous solution. The result showed that the Cu@GLA-PEI-CA-1 catalyst displayed high kinetic responses with a kinetic reaction rate constant of 1.60 × 10 −2 s −1 , which was higher than that of Cu@GLA-PEI-CA-0 (without CaCO 3 template) and Cu@GLA-CA-1 (without PEI coating). The enhanced catalytic performance was resulted from homogeneous distribution of Cu NPs along with the tailored microstructure and the hydrophilic surface of the support. Additionally, the dynamic catalytic experiment was conducted to investigate the catalytic performance of Cu@GLA-PEI-CA-1 beads as the catalyst. We expected that this work could provide a new and effective strategy to design highly efficient catalysts for various catalytic reactions.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 10
·2331
·
IF 4.2
Renzhou Hong,Xijun Zhao,Rongyu Lu,Meng You,Xiaofang Chen,Xiaoming Yang
Conducting polymers like polypyrrole, polyaniline, and polythiophene with nanostructures offers several advantages, such as high conductivity, a conjugated structure, and a large surface area, making them highly desirable for energy storage applications. However, the direct synthesis of conducting polymers with nanostructures poses a challenge. In this study, we employed a hard template method to fabricate polystyrene@polypyrrole (PS@PPy) core–shell nanoparticles. It is important to note that PS itself is a nonconductive material that hinders electron and ion transport, compromising the desired electrochemical properties. To overcome this limitation, the PS cores were removed using organic solvents to create hollow PPy nanospheres. We investigated six different organic solvents (cyclohexane, toluene, tetrahydrofuran, chloroform, acetone, and N,N-dimethylformamide (DMF)) for etching the PS cores. The resulting hollow PPy nanospheres showed various nanostructures, including intact, hollow, buckling, and collapsed structures, depending on the thickness of the PPy shell and the organic solvent used. PPy nanospheres synthesized with DMF demonstrated superior electrochemical properties compared to those prepared with other solvents, attributed to their highly effective PS removal efficiency, increased specific surface area, and improved charge transport efficiency. The specific capacitances of PPy nanospheres treated with DMF were as high as 350 F/g at 1 A/g. And the corresponding symmetric supercapacitor demonstrated a maximum energy density of 40 Wh/kg at a power density of 490 W/kg. These findings provide new insights into the synthesis method and energy storage mechanisms of PPy nanoparticles.
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Materials Interfaces
·
2021
·Vol. 8
·期 13
·2100244
·
IF 6.147
Le Li,Zhi Xu,Xiaoxia Chen,Chenhong Fang,Deyue Yan,Guyu Xiao
The pore structures of carbons profoundly affect their properties and functions. The hard template method has been extensively employed to fabricate porous carbons. Generally, the heteroatoms of porous carbons remarkably boost their performances, thus various of strategies have been carried out to incorporate the heteroatoms into porous carbons. The usual hard templates, such as silica nanoparticle and polystyrene sphere, only function as a pore-forming agent. Herein, nanoscale melamine resin spheres (NMRSs) are fabricated for the first time. NMRSs can be decomposed to generate the template mesopore in situ during the pyrolysis of carbon precursors. Moreover, NMRSs also can work as a nitrogen-dopant for porous carbons. As a demonstration, the N,P-codoped hierarchically porous carbons are prepared using NMRSs as both pore-forming agent and dopant, which exhibit excellent catalytic performances for the oxygen reduction reaction (ORR), close to or better than those of the best performing metal-free doped carbon catalysts for the ORR. Therefore, this bifunctional template paves a facile pathway to fabricate porous carbons.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2015
·
IF 3.453
Hui-Min Zhao,Chang-Miao Di,Lan Wang,Yuan Chun,Qin-Hua Xu
Mesoporous graphitic C 3 N 4 has been synthesized using a novel cross-linked bimodal mesoporous (CLBM) SBA-15 as a hard template. This cross-linked bimodal mesoporous SBA-15 template was prepared by adjusting the pH to alter the copolymer micelle size. The resulting mesoporous g -C 3 N 4 replicates the morphology of the mesoporous silica template, and numerous pore openings are formed on the surfaces. The mesoporous g -C 3 N 4 exhibits a high specific surface area and a large pore volume . The photocatalytic degradation activity of methyl orange on mesoporous g -C 3 N 4 is nearly 15.3 times as high as that on bulk- g -C 3 N 4 under visible light irradiation. The high photocatalytic performance of this sample is due to the high specific surface area and more readily accessible active sites.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Interfaces
·
2016
·Vol. 4
·期 3
·1600862
·
IF 3.365
Cunlong Yu,Cunming Yu,Liying Cui,Zhiyang Song,Xinyu Zhao,Ying Ma,Lei Jiang
Nowadays, oily wastewater and spilled oil have caused great threats on both ecosystem and human life. To address these severe problems, considerable efforts have been possessed on developing novel oil/water separation materials. The porous oil-absorbent materials, especially the porous polydimethylsiloxane (PDMS) with excellent properties of easy fabrication and inherent hydrophobicity, have attracted tremendous attentions from worldwide. The conventional methods using salt or sugar as sacrificial template and water as solvent have been widely adopted to fabricate the porous PDMS sponge. Due to the inherent hydrophobicity of PDMS, the solvent of water hardly penetrates into the inside of PDMS, which results in the difficult and incomplete remove of the hard template. In this contribution, the 3D interconnected porous PDMS sponge is facilely prepared by utilizing a modified technique with the citric acid monohydrate as hard template and ethanol as solvent. The proposed approach is capable of removing the hard template efficiently and thoroughly, which demonstrates promising utilizations in practical applications.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2020
·Vol. 167
·期 4
·040505
·
IF 3.721
Longfei Qin,Zuoyi Xiao,Shangru Zhai,Shifu Wang,Haisong Wang,Guoxiang Wang,Weijie Cai,Zhongcheng Li,Qingda An
Biomass-derived hierarchical porous carbons have attracted considerable attention due to their low cost, environmental friendliness and sustainability. However, the preparation of porous carbon with typically hierarchical pores is still challengeable. In this work, a facile and efficient strategy was proposed to obtain alginate-derived porous carbon by a combination of hard-template and chemical-activation technique. During the fabrication process the nano-ZnO particles displayed triple functions: (a) The nano-ZnO particles were behaved as the hard template to generate more pores. (b) ZnCl2 derived from the nano-ZnO particles acted as a cross-linking agent for obtaining zinc alginate (Zn-SA) hydrogel beads. (c) ZnCl2 was also employed as an activating agent to form micropores during the high-temperature carbonization process. As a subsequence, the obtained carbon exhibited well-developed hierarchical porous structure with high specific surface area of up to 2589 m2 g−1. Due to the high specific surface area, good electrical conductivity and synergistic effect among the typically hierarchical pores, the PC-ZnO-ZnCl2-650 exhibited a high specific capacitance of 316 F g−1 at the current density of 0.5 A g−1 and excellent cycling stability with capacitance retention of 94.4% at 5 A g−1 over 5000 cycles. This ingenious synthesis strategy can provide a new way for efficient preparation of hierarchical porous material.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Zi-Chun Fan,Xiang Bai,Xian-Yong Wei,Xing Fan,Yierxiati Dilixiati,Zhuang Li,Qian-Qian Kong,Ji Zhao,Li Li,Jia-Hao Li,Zhi-Min Zong
The efficient and clean utilization of low-rank lignite conforms the strategy of carbon neutral development. Herein, a two-step strategy of hard template method and co-precipitation method was designed to prepare nickel nanoparticles supported on mesoporous carbon (Ni x /MPC) using the residue from the ethanolysis of Longquan lignite for quantitative detection of p -nitrophenol (NP). The electrochemical reduction properties of modified glassy carbon electrodes (GCEs) with different nickel loadings ( x = 10, 15, and 20 wt%) for NP were compared, in which Ni 15 /MPC/GCE stood out and presented better conductivity, larger electrochemical active surface area, and faster electron transfer rate. According to the differential pulse voltammetry detection results, Ni 15 /MPC/GCE displays satisfactory detection limit (1.8 µM) and far wider detection concentration range (170 ∼ 10000 µM) than other reported electrochemical sensors. Moreover, Ni 15 /MPC/GCE exhibits acceptable stability and reproducibility, and the relative standard deviation of NP detection current is only 0.71% under the interference of 100-fold concentration interfering substances. Hence, the constructed Ni 15 /MPC/GCE demonstrates a promising electrochemical sensor for detecting NP in environmental sewage.
研究领域:
环境科学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2016
·
IF 2.101
Shunyu Han,Zheng Wang,Longyue Meng,Nanzhe Jiang
Mesoporous ZSM-5 zeolites were synthesized by using hydrophilic carbon black as a hard template. Hydrophobic carbon black was oxidized with sodium hypochlorite solution then dispersed into the synthetic precursor, and hydrothermally treated by omitting the evaporation process. The samples were characterized by SEM, TEM, XRD , nitrogen adsorption/desorption and NH 3 -TPD measurements. As a result, mesoporous ZSM-5 zeolites were obtained in the morphology of single crystal like aggregates (about ∼2 μm) with intra-mesopores in the range of 5–18 nm. Textural properties and acidity of mesoporous ZSM-5 zeolites were varied by adjusting the amount of carbon black used. In the toluene disproportionation, mesoporous ZSM-5 templated by hydrophilic carbon black showed more active in toluene conversion and more selective to the para -xylene than conventional zeolite, and even comparable to the commercial zeolite catalyst.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）