Science of Advanced Materials
·
2015
·Vol. 7
·期 3
·526-531
·
IF 2.598
Chen Xiang,Gao Qian,Xiang Di,Lin Huiming,Han Xiao,Li Xin,Du Shantao,Qu Fengyu
Porous ZnO nanofibers were prepared through the electrospun method using zinc acetate as zinc source and polyvinylpyrrolidone as thickener agent. Under adjusting the amount of zinc acetate, the synthesized porous ZnO nanofibers show various structures (fiber, tube, and fiber-in-tube).
And the formation mechanism was discussed in detail. These porous ZnO samples show the uniform structure about 200 to 300 nm in diameter and several microns in length. All the fibers are composed of many ZnO nanoparticles (20–30 nm) that assemble to form the porous structure and induce
the large surface area and high pore volume of the sample. These porous ZnO nanofibers were configured as high performance sensors for acetone sensing, showing high sensitivity (S = 243.3 at 500 ppm), low detection limit (10 ppm), fast response/ recovery (7/17 s), and very good selectivity.
研究领域:
材料科学
·
传感器技术
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2018
·
IF 6.945
Shukai Yu,Ning Sun,Longfeng Hu,Le Wang,Qizhen Zhu,Yibiao Guan,Bin Xu
Hierarchical porous texture is regarded as an ideal design for carboneous electrode materials of supercapacitors as it can present both high capacitance and good rate performance. Here, we propose a very simple and effective strategy to prepare nitrogen-doped, hierarchical porous carbons by direct pyrolysis of ethylenediamine tetraacetic acid disodium zinc salt, which plays multi-roles of carbon precursor, nitrogen source, hard template and activation agent all in one. During the pyrolysis process, ethylenediamine tetraacetic acid disodium zinc salt is firstly decomposed to a composite of nitrogen-doped carbon, nano-ZnO and Na 2 CO 3 particles. The nano-ZnO and Na 2 CO 3 particles are evenly embedded in the carbon matrix, acting as hard templates to create mesopores. Furthermore, the nano-ZnO also contributes to micropore creation as an activation agent at further increasing temperature. As a result, the nitrogen-doped, hierarchical porous carbons are easily obtained. The large surface area (1368 m 2 g −1 ) and high nitrogen content (6.71 at%) enable the carbon prepared at 700 °C exhibits a high capacitance of 275 F g −1 and excellent rate capability (207 F g −1 at 100 A g −1 ) in 6 mol L −1 KOH aqueous electrolytes , indicating a promising candidate as a carbon electrode material for supercapacitors.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
ChemPlusChem
·
2014
·Vol. 79
·期 7
·907-913
·
IF 3.242
Xiang Wang,Pengcheng Huang,Ping Yu,Lifen Yang,Lanqun Mao
In this study, a new method was developed for the rapid and cost-effective synthesis of nanosized zeolitic imidazolate framework-7 (ZIF-7) nanocrystals with a high yield and a low molar ratio of benzimidazole ligand to metal salt (2:1) by using N , N′- dimethylformamide (DMF) as the solvent and zinc acetate dihydrate (Zn(OAc) 2 ⋅2 H 2 O) as the metal source. The synthesized ZIF-7 nanocrystals have a size of approximately 50–80 nm, and tend to aggregate or become intergrown to form irregular nanoparticles of about 200–300 nm in size. The morphology and yield of the ZIF-7 nanocrystals can be tuned easily by changing the synthetic parameters such as the composition of the solvent and concentrations of reagents. The synthesized ZIF-7 nanocrystals exhibit good thermal and chemical stability, CO 2 capture capability, and fluorescent properties. Remarkably, we find that the synthetic strategy developed here can be extended to the syntheses of other kinds of ZIFs including ZIF-69 and ZIF-90. This study offers a new, simple synthetic strategy for the high-yield preparation of ZIF materials. Graphical Zeolitic nanocrystal control : We have developed a new method for the rapid and cost-effective synthesis of nanosized zeolitic imidazolate framework (ZIF-7) nanocrystals with a high yield and a stoichiometric molar ratio of ligand to metal salt (2:1) by using N , N ′-dimethylformamide (DMF) as the solvent and zinc acetate as the metal source (see figure). This strategy can also be extended to the synthesis of ZIF-69 and ZIF-90.
研究领域:
材料化学
·
纳米科技
·
配位聚合物
·
多孔材料
·
气体吸附
·
功能材料
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Zihan Chen,Yaohong Zhang,Zhi Li Teh,Jianfeng Yang,Lin Yuan,Gavin J. Conibeer,Robert J. Patterson,Qing Shen,Shujuan Huang,Zhilong Zhang
Quantum dots (QDs) have a wide range of applications in the field of optoelectronics. They have been playing multiple roles within the configuration of a device, by serving as the building blocks for both the active layer and the carrier transport layer. While the performance of various optoelectronic devices has been steadily improving via developments in passivating the QD active layer, the possible improvement via passivation of the QD-based carrier transport layer has been largely overlooked. Here, with lead sulfide QD photovoltaics as the platform of study, we demonstrate that the device performance can be significantly improved by passivating the QD hole transport layer (HTL) with zinc salt post-treatments. The power conversion efficiency is improved from 8.7% of the reference device to 10.2% and 9.5% for devices with zinc acetate (ZnAc)- and zinc iodide (ZnI2)-treated HTLs, respectively. Transient absorption spectroscopy confirms that both treatments effectively reduce band-tail states and increase carrier lifetime of the HTLs. Further elemental analysis shows that ZnAc provides a higher amount of Zn2+ for passivation while maintaining the function of HTL by allowing essential p-doping oxidation. In contrast, the additional I– passivation from ZnI2 inhibits p-doping oxidation and limits the function of HTL. This work demonstrates the potential of improving device performance by passivating the QD-based HTLs, and the method developed is likely applicable to other optoelectronic devices.
研究领域:
光电子学
·
纳米材料
·
光伏技术
·
半导体物理
✓ 已验证
DOI
高影响因子
RSC Sustainability
·
2025
·
IF 4.9
ZIXIAN JIA,JIE ZHANG,LIN GAO,LIJIAO QIN,HAOCHENG SUN,JIAXING CHEN,Jian-Zhong Yin
The chemical recycling of polyethylene terephthalate (PET) via glycolysis is a promising route for recovering the monomer bis(2-hydroxyethyl) terephthalate (BHET), which can be used for virgin-grade PET production. However, the influence of water—an inevitable impurity and potential byproduct—on this process is complex and not fully elucidated. This study systematically investigates the effect of water content (0–22.2 vol%) on PET glycolysis using selected heterogeneous catalysts (ZnO, Mn₂O₃) and homogeneous catalysts (zinc acetate (ZnAc₂), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)). Product distribution and reaction kinetics were quantified by HPLC and in-situ IR spectroscopy, respectively.The heterogeneous catalysts (ZnO, Mn₂O₃) and homogeneous ZnAc₂ maintained high PET conversion (>95%) even at elevated water concentrations. Nevertheless, the BHET yield and selectivity for these systems decreased significantly due to a competing hydrolytic side reaction, promoted by water, which yields terephthalic acid (TPA). Notably, ZnAc₂ exhibited a more rapid decline in BHET selectivity compared to ZnO. Conversely, the organic base catalysts TBD and DBU experienced complete deactivation in the presence of water, resulting in a drastic reduction in both PET conversion and BHET yield, with DBU showing greater susceptibility. In-situ IR experiments corroborated that the deactivation mechanism for TBD involves protonation by water. These results emphasize that water's influence is a function of the catalyst's chemical nature, modulating product selectivity for metal-based systems while causing the deactivation of organic bases. Understanding these divergent effects is critical for the optimization of industrial PET glycolysis and the rational design of water-tolerant catalytic systems.
研究领域:
高分子化学
·
催化化学
·
化学回收
·
反应工程
·
环境化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）