INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2013
·
IF 3.548
Rencheng Jin,Guihua Li,Yanbin Xu,Junshen Liu,Gang Chen
Hierarchical Bi 2 S 3 hollow spheres have been synthesized by a facile solvothermal process in the presence of sodium tartrate . The hollow spheres are composed of numerous ultrathin nanorods with the average diameter of 15 nm. Based on the time dependent electron microscope observations, the formation mechanism of such hierarchical structures has been proposed as a sodium tartrate directed self-assembled process and oriented attachement mechanism. The morphology and size of the subunits can be controlled by adjusting the amount of sodium tartrate. The Nitrogen adsorption-desorption measurements suggest that mesopores exist in these hollow spheres. The as-derived Bi 2 S 3 hollow spheres exhibit excellent electrochemical hydrogen storage properties.
研究领域:
材料科学
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纳米技术
·
能源存储
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Chenchen Cheng,Zhaoqi Zhu,Mingxing Wang,Hanxue Sun,Jiyan Li,Rui Jiao,An Li
Epoxy resin, as a thermosetting polymer material with good performance, has been limited in application due to its high flammability. In this investigation, porous CuO-ZnO hollow spheres (CZHS) were prepared by a hydrothermal method. By incorporation with ionic liquids loaded CuO-ZnO hollow spheres (CZHS@Ils) and ammonium polyphosphate (APP) into epoxy resin (EP) matrix, a new composite flame retardant material, named as EP/7.5APP/1.5CZHS@ILs, was developed for improvement of their thermal insulation and flame retardancy. The thermal conductivity of EP/7.5APP/1.5CZHS@ILs was measured to be 0.0197 W m −1 K −1 , which is lesser than that of APP incorporated epoxy resin (EP/APP), demonstrating good thermal insulation capability. The flame retardancy were assessed using the limiting oxygen index (LOI) test, the Vertical flame testing (UL-94) test, and the cone calorimeter (CC) test. The results obtained from LOI test show that the EP/7.5APP/1.5CZHS@ILs has good flame retardancy with a LOI value of up to 28, better than that of pure EP which has a LOI value of 19.2. Moreover, a V-0 level of the EP/7.5APP/1.5CZHS@ILs was observed from the UL-94 test. The peak heat release rate (PHRR) was reduced to 257.9 kW m −2 , which is 74.8 % lower than that of the pure EP. Such results are attributed to the synergy effect of CZHS@ILs and APP which offers the epoxy resin excellent flame retardancy. Taking advantages of the excellent thermal insulation, flame retardancy and better mechanical properties, the as-resulted EP/7.5APP/1.5CZHS@ILs may hold great potential for future thermal insulation and flame-retardant applications of energy saving building.
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
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2020
·Vol. 25
·期 1
·267-278
·
IF 2.646
Yao Shaowei,Zhang Guifang,Zhang Xingxiang,Zhao Yabin,Shi Zhiqiang
In this work, α-Fe 2 O 3 double-layer hollow spheres with carbon coating (DLHS@C) are synthesized by a general “penetration-heterogeneous nucleation” approach using carbonaceous sphere templates combined with subsequent annealing. This hierarchy hollow sphere structure with carbon coating rationally combines three advantage aspects: shorten transport length for lithium ions and charges, sufficient void space to buffer the volume expansion, and enhanced electric conductivity. When tested for lithium storage, α-Fe 2 O 3 DLHS@C composite electrode exhibits a high initial discharge capacity of 1735 mAh g -1 and the reversible capacity of 823 mAh g -1 after 100 cycles at the current density of 100 mA g -1 in the voltage range of 0.01–2.5 V (vs. Li + /Li) and retains a capacity of 470 mAh g -1 even at a large current density of 500 mA g -1 after 500 cycles. The α-Fe 2 O 3 DLHS@C electrode demonstrates excellent electrochemical properties with high capacity, good cycling stability, and excellent rate capability as potential anode material for lithium ion batteries.
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
RSC Advances
·
2018
·Vol. 8
·期 31
·17151-17158
·
IF 2.936
Qionglin Luo,Shunqin Zeng,You Shu,Zaihui Fu,Hongran Zhao,Shengpei Su
A polystyrene-hollow sphere catalyst was prepared by treating polystyrene-encapsulated calcium carbonate particles with concentrated hydrochloric acid. This catalyst was characterized using TGA, FT-IR, optical microscope, SEM-EDX and XPS. Evidences from SEM-EDX and XPS analyses indicated that the sulfonate groups were on the inner surface of the polystyrene hollow sphere. The polystyrene hollow spheres were used as catalyst in the hydrolysis of tannic acid. Reaction conditions including the reaction temperature and time, loading of catalyst, ratio of tannic acid to H2O and number of recycles were optimized. A high yield of gallic acid was obtained as the reaction performed under the following conditions: a temperature of 80 °C, a molar ratio of tannic acid to H2O of 1 : 3, and a catalyst loading of 7% w/w (based on the mass of tannic acid). This catalyst showed excellent catalytic performance, easy separation, high stability and good reusability. This work provides a new strategy for the controllable synthesis of polystyrene hollow structures with sulfonic groups on the inner surface and an excellent and prospective catalyst for the production of gallic acid through hydrolysis of tannic acid.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
ChemCatChem
·
2018
·Vol. 11
·期 3
·1057-1063
·
IF 4.674
Gan Wang,Lijuan Zhang,Baolin Yan,Jianmin Luo,Xintai Su,Fan Yue
Graphical It's a vacancy-rich world ! During the liquid-nitrogen quenching process, the isolated O atoms on the TiO 2 surface are partially frozen and lose the opportunity to return the crystallographic sites, leaving abundant oxygen vacancy on the surface. The oxygen vacancy-rich TiO 2 prepared via liquid-nitrogen quenching exhibited outstanding advantages on photocatalytic H 2 evolution. Development of novel methods to obtain highly active catalysts for photocatalytic hydrogen evolution is desired. This work reports a facile preannealing-quenching strategy to synthesize oxygen vacancy-rich anatase TiO 2 hollow spheres. TiO 2 hollow spheres are first synthesized via a versatile kinetics-controlled coating method and then subjected to high temperature preannealing followed by rapid quenching in liquid-nitrogen (−196 °C). The as-quenched samples appear light grey suggesting the presence of abundant surface oxygen vacancies, which are subsequently confirmed by the comprehensive analyses of XRD, XPS and EPR spectra. The oxygen vacancies induced by quenching process are proved to have promoted the light adsorption and inhibited the recombination of photo-induced charges for TiO 2 hollow spheres, which obviously improve the photocatalytic performance of those samples. The results showed that the TiO 2 hollow spheres quenched at 500 °C exhibited a robust stability and the most excellent photocatalytic performance for hydrogen evolution (413.5 μmol h −1 ) over other quenched samples and it displayed 1.51 times higher performance than that of samples normally cooled at 500 °C (273.7 μmol h −1 ). Herein, this liquid-nitrogen quenching strategy presented here provides an effective route for the synthesis of high-performance TiO 2 for water splitting and have a promising prospect in the other application.
研究领域:
材料科学
·
催化
·
纳米技术
·
能源转换
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 2
·132
·
IF 4.034
Libo Yu,Zhen Li
ZnxCd1-xSe@ZnO hollow spheres (HS) were successfully fabricated for application in quantum dot sensitized solar cells (QDSSCs) based on ZnO HS through the ion-exchange process. The sizes of the ZnxCd1-xSe@ZnO HS could be tuned from ~300 nm to ~800 nm using ZnO HS pre-synthesized by different sizes of carbonaceous spheres as templates. The photovoltaic performance of QDSSCs, especially the short-circuit current density (Jsc), experienced an obvious change when different sizes of ZnxCd1-xSe@ZnO HS are employed. The ZnxCd1-xSe@ZnO HS with an average size distribution of ~500 nm presented a better performance than the QDSSCs based on other sizes of ZnxCd1-xSe@ZnO HS. When using the mixture of ZnxCd1-xSe@ZnO HS with different sizes, the power conversion efficiency can be further improved. The size effect of the hollow spheres, light scattering, and composition gradient structure ZnxCd1-xSe@ZnO HS are responsible for the enhancement of the photovoltaic performance.Keywords:alloyed quantum dots;hollow spheres;sensitized solar cells;zinc oxide
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2017
·
IF 6.844
Yan Cao,Zipeng Xing,Mengqiao Hu,Zhenzi Li,Xiaoyan Wu,Tianyu Zhao,Ziyuan Xiu,Shilin Yang,Wei Zhou
Mesoporous black N-TiO 2−x hollow spheres are successfully fabricated through a facile evaporation-induced self-assembly (EISA) process, coupled with an etching procedure and an in-situ solid-state chemical reduction strategy. The resultant black N-TiO 2−x hollow spheres with high crystallinity possess a narrow band gap of ∼2.37 eV, a large specific surface area of ∼128 m 2 g −1 , and a well defined hollow sphere structure, which exhibit excellent visible-light-driven photocatalytic performance for degradation of phenol , reduction of Cr(IV), and hydrogen production . The photocatalytic reaction apparent rate constants (k) of the black N-TiO 2−x for phenol degradation and Cr(IV) reduction are ∼5 and 6 times higher than that of pristine TiO 2 , and hydrogen production rate for N-TiO 2−x is ∼160 μmol h −1 , which is ∼7 folds higher than that of pristine one. The excellent photocatalytic and photoreduction property can be attributed to the synergy effect of N and Ti 3+ codoping narrowing the band gap, the high specific surface area offering more surface active sites, and the mesoporous hollow structure favoring light harvesting and refraction.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Peiyao Wang,Jin Bai,Kunzhen Li,Hongyang Ma,Wanyun Li,Xuebin Zhu,Yuping Sun,Bangchuan Zhao
Transition metal nitrides are of great interest for lithium storage application due to their high electrical conductivity and low voltage plateau. However, the relative cycling stability restricts their practical application. Herein, a stable bimetal nitride NiCo 2 N hollow sphere material with interconnected nanosheets shell was successfully synthesized via a facial solvothermal route. When used as anodes for lithium-ion batteries, the unique structure can effectively relieve the volume change of the electrode material , and shorten the diffusion distance of lithium ions during the repeated cycling processes. As a result, the NiCo 2 N electrode exhibits an excellent electrochemical performance. It delivers high discharge capacity of 1244.5 mAh g −1 at a current density of 1 A g −1 after 400 cycles, the capacity can maintain 529.4 mAh g −1 at high current density of 5 A g −1 . Furthermore, the electrochemical reaction mechanism of the electrodes is revealed by ex situ XRD, ex situ EIS, and ex situ HRTEM characterization.
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
Catalysts
·
2021
·Vol. 12
·期 1
·33
·
IF 4.146
Yulin Li,Ping She,Rundong Ding,Da Li,Hongtan Cai,Xiufeng Hao,Mingjun Jia
Polyacrylonitrile hollow nanospheres (HPAN), derived from the polymerization of acrylonitrile in the presence of polystyrene emulsion (as template), were modified by surface amination with ethylenediamine (EDA), and then used as support for loading Pd or PdCo nanoparticles (NPs). The resultant bimetallic catalyst (named PdCo0.2/EDA-HPAN) can efficiently catalyze the additive-free dehydrogenation of formic acid with very high activity, selectivity and recyclability, showing turnover frequencies (TOF) of 4990 h−1at 333 K and 915 h−1at 303 K, respectively. The abundant surface amino groups and cyano group as well as the hollow structure of the support offer a suitable environment for achieving high dispersion of the Pd-based NPs on the surface of EDA-HPAN, thus generating ultra-small bimetallic NPs (bellow 1.0 nm) with high stability. The addition of a small portion of Co may adjust the electronic state of Pd species to a certain extent, which can further improve their capability for the dehydrogenation of formic acid. In addition, the surface amino groups may also play an important role in synergistically activating formic acid to generate formate, thus leading to efficient conversion of formic acid to hydrogen at mild conditions.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2024
·
IF 5.4
Lichao Zuo,Yuanyuan Bao,Ke Wu,Shujing Li,Zhaohui Qu,Yongbo Lyu,Xiaozhen Li,Hong Meng,Yifan He
The increasing prevalence of antibiotic-resistant bacteria is regarded as one of the worst threats to the environment and global health, and antimicrobial nanomaterials have been increasingly explored to provide solutions for antimicrobial resistance problems. In this paper, mesostructured Zn-doped CeO 2 hollow spheres (ZDCHS) with various Zn/Ce ratios were successfully prepared by a conventional one-pot hydrothermal synthesis method. The ingenious incorporation of Zn playing a vital role in the fabrication of hollow structure of ZDCHS with high specific surface area, and detailed transmission electron microscopy (TEM) characterization confirmed the homogeneous distribution of Zn element across the ZDCHS. The X-ray photoelectron spectroscopy (XPS) and Raman results indicated that a higher concentration of oxygen vacancies was obtained on the ZDCHS compared to the undoped CeO 2 counterparts. In addition, the in vitro antioxidant properties evaluated toward scavenging DPPH radicals, hydroxyl radicals and superoxide radicals further revealed the enhanced antioxidant activity of ZDCHS derived from the doping with Zn ions. Furthermore, the bacteriostatic assay against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria showed that the ZDCHS possessed synergistically improved bacteriostatic performance and were more susceptible to S. aureus with a maximal antimicrobial ratio of 99.5 %, which is higher than that of the undoped CeO 2 samples (80.7 %). These results represent a new paradigm to the design of novel hollow-structured materials, highlighting the doping of Zn ions in the lattice structure of CeO 2 provides a feasible means for the preparation of effective antioxidants and antimicrobial agents.
研究领域:
材料科学
·
微生物学
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Xinyu Wang,Yuhan Yao,Wei Gao,Zhaolin Zhan
TiO 2 is exceptionally useful anode material for Li-ion batteries, and the ability to modify TiO 2 makes it a very attractive and challenging research object for use in different functional materials . In this paper, mesoporous TiO 2 nano hollow spheres (dubbed TiO 2 -1 andTiO 2 -2) with moderate oxygen vacancies were successfully prepared. Structure and composition characterizations revealed that the spheres had a hollow structure, surface oxygen vacancies and an excellent Ti 3+ /Ti 4+ molar ratio of 0.181. In addition, TiO 2 -2 demonstrated synergistic effects in terms of electron and lithium ion transportation, with impedances as low as 3.05 Ω, and its Li-ion diffusion coefficient (7.8 × 10 −12 cm 2 s −1 ) was at least a factor of 10 larger than that of TiO 2 -1(6.2 × 10 −13 cm 2 s −1 ). More importantly, experiments demonstrated that the well-balanced Li + /e − transportation arising from the synergetic effect between structure and Ti 3+ /oxygen vacancy in the optimal TiO 2 -2 sample had a high specific capacity of 233 mAh·g −1 at 0.1C, and 79.8% capacity retention after 100 cycles, as well as greatly enhanced rate performance and electrochemical reactivity and stability in comparison with the other TiO 2 . Our method for creating oxygen vacancies in TiO 2 nano hollow spheres can be generalized to other electrochemical energy storage materials .
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Shujuan Wu,Zhaoqi Zhu,Chao Liu,Yanning Su,Fei Wang,Wei Bai,Hanxue Sun,Weidong Liang,An Li
The development of functional materials with better flame-retardant and thermal insulation properties has attracted considerable attention for energy storage applications in modern society. Here, we describe a facile approach for the preparation of conjugated microporous polymer hollow spheres (CMP-HSs) by using SiO 2 nanoparticles as a template via the Sonogashira-Hagihara cross-coupling reaction. The as-synthesized CMP-HSs have good thermal stability with a thermal decomposition temperature of up to 281 °C, high porosity (the BET specific surface area is measured to be approximately 666 m 2 g −1 ) along with lipophilic and hydrophobic characteristics. To further improve their flame retardancy, CMP-HSs were treated with dimethyl phosphonate (DMMP) though an immersion method to prepare the CMP-HSs composite (CMP-HSs-DMMP) flame-retardants. By introducing CMP-HSs-DMMP into the epoxy resin (EP) matrix, the as-prepared EP composites showed excellent flame-retardant properties, e.g., the peak heat release rate (pHRR) and total heat release (THR) value of EP composites containing only 0.2% CMP-HSs-DMMP flame-retardant were 650.9 kW m −2 and 79.4 MJ m −2 respectively, in the range of 0 °C − 650 °C, which are 19.6 ± 2% and 19.1 ± 5% lower than that of pure EP within the same temperature range. Considering the significant enhancement of its flame retardancy with only a slight dosage of CMP-HSs-DMMP, such CMP hollow sphere-based flame-retardant composites may have great potential as functional bulk materials or coatings in a variety of fireproofing applications.
研究领域:
材料科学
·
能源存储
·
阻燃材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）