JOURNAL OF MATERIALS SCIENCE
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2011
·Vol. 47
·期 2
·711-719
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IF 1.859
Jin Quan,Zheng Mingtao,Wu Yongjian,Xie Chunlin,Xiao Yong,Liu Yingliang
A facile approach was developed for synthesis of carbon hollow microspheres (CHM) via carbonization of the hollow polymer microspheres prepared from polymerization in the presence of l -lysine acted as in situ template. The physical and chemical structures of the samples were investigated by X-ray powder diffraction, Raman spectrum, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). SEM and TEM images show that the products consist of a large scale of monodisperse CHM with a size of about 1.1–1.3 μm. Furthermore, the resulting CHMs possess a surface area of 559 m 2 g −1 and a pore volume of 0.27 cm 3 g −1 . The morphology and the size of the as-obtained samples can be controlled by the polymerization temperature, polymerization time, and the dosage of l -lysine. Moreover, a possible formation mechanism of the CHM has been put forward according to the experimental data available.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Lei Wang,Zeen Yv,Licheng Ma,Qi Zheng,Tong Wang,Xiaokui Che,Xinglan Cui,Hongxia Li,Shenyv Wei,Xinyue Shi
Calcium carbonate is a common natural mineral with a wide range of applications. In this study, hollow calcite microspheres were successfully synthesized by using calcium chloride and sodium carbonate as raw materials in an SDS–PEG system. The results suggested that the appropriate concentration of SDS is necessary during the spherical crystallization of calcium carbonate. It was found that the crystals started to aggregate under the effect of SDS, and aggregation was enhanced with an increase in SDS concentration, leading to the transformation from hollow to solid microspheres. However, high temperatures will lead to the transformation from calcite to aragonite, resulting in the collapse of the formed spherical structure. Infrared spectroscopy and conductivity analysis suggested that when the concentration of SDS reached 0.3 g/L in the PEG–SDS system, SDS and PEG formed a spherical supramolecular structure. This structure could act as a template, leading to the aggregation of calcite through electrostatic attraction and finally to the formation of a hollow spherical structure.
研究领域:
材料科学
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化学工程
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DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2017
·Vol. 93
·期 4
·1147-1158
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IF 3.135
Chongzhuo Bao,Chen Mingxin,Guangrong Liu,Xin Jin,Qiang Huang
BACKGROUND Uniform and well-dispersed hollow microspheres of oligoaniline were synthesized by a facile and template-free method in alkaline medium. The morphology of oligoanilines was controlled from hollow to hard microspheres, by simply changing the volumes of alkaline medium. SEM, TEM, XRD, FTIR and physical adsorption of nitrogen were used to characterize the products. Hexavalent chromium ion uptake experiments were run with these aniline oligomers. RESULTS Adsorption experiments showed that the removal of chromium ions was strongly dependent on the initial pH of the solution. The pseudo-second-order kinetic and Langmuir isotherm models were well correlated with the experimental data. The adsorption of Cr(VI) and synergistic reduction to Cr(III) were confirmed by analyzing remnant chromium in the liquid and XPS detection of the exhausted adsorbent. A redox/pseudo-protonation process was suggested as the mechanism to explain the Cr(VI) removal. The adsorbed chromium ions could be desorbed by NaOH solution. The higher desorption efficiency of 96.2% was achieved by using 1.0 mol L -1 NaOH as the desorption agent. CONCLUSIONS It was observed that the hollow microsphere were the most effective adsorbent of the three adsorbents and its removal efficiency reached 99% to remove 60 mg L -1 Cr(VI). The facile fabrication, efficient removal of Cr(VI) and simple regeneration offered an option to remove Cr(VI) contamination from natural water and industrial wastewater. © 2017 Society of Chemical Industry
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
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2025
·
IF 4.6
Xin Tian,Jianru Chen,Ruobing Jiang,Haiyang Chen,Jielin Zhang,Jinlong Ren,Xihao Yu,Lina Liu,Chenchen Feng,Cuixia Li,Fucheng Yu,Kechao Hu,Xiaogang Hou
Hydroxylated carbon quantum dots (OH-CQDs) modified g-C 3 N 4 hollow microspheres were prepared using a supramolecular precursor self-assembly method. The incorporation of OH-CQDs into the precursor resulted in the formation of a hollow flower-like microsphere structure composed of g-C 3 N 4 nanoflakes in the final samples, which exhibited a morphology that was roughly inherited from that of the supramolecular precursor. The incorporation of an optimal quantity of OH-CQDs did not result in a deterioration of the g-C 3 N 4 product morphology; rather, it led to an enhancement in its microsphere structure. The modified nanostructure of g-C 3 N 4 resulted in a significant increase in reaction sites and promoted the adsorption of organic dye molecules on the surface of the g-C 3 N 4 photocatalyst during degradation reactions. Furthermore, despite the reduction in carrier concentration of g-C 3 N 4 resulting from the decoration with OH-CQDs, the impedance was significantly diminished and the photocurrent density was also markedly improved. It can thus be concluded that the decoration of OH-CQDs has significantly enhanced the mobility of g-C 3 N 4 , thereby contributing to the improvement of the photocatalytic performance of the g-C 3 N 4 photocatalyst.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Yijun Yao,Jiannan Xue,Miao Wang,Dong Fu,Yanqin Shen,Ying Xue,Fan Zhang,Pengbi Liu,Hongru Wang,Hailiang Wu
Herein, a facile, green, and universal method to prepare polymer fluorescent films was proposed. Firstly, hollow cellulose-based microspheres were prepared by cross-linking copolymerization and self-assembly strategy. Then, after encapsulating the hydrophobic fluorescent dye fluorescein isothiocyanate (FITC) into the cavity of a hollow cellulose-based microsphere through the ultrasonic/dialysis method, a series of flexible fluorescent microsphere films with tunable fluorescence was obtained. The formation of hollow cellulose-based microspheres was confirmed by SEM. DLS, AFM, and UV–vis analysis provided evidences for the successful encapsulation of FITC in hollow cellulose-based microspheres. Benefiting from the synergistic effects of “anchoring”, “diluting” and “isolation” for cellulose polymer chain as well as the hollow structure, the aggregation and self-quenching of FITC were effectively inhibited, which promoted the fluorescent films with different loading amount to emit green fluorescence under 365 nm UV light irradiation, and the fluorescence intensity was tunable. Moreover, the fluorescent films exhibited strong UV absorption, excellent optical stability, foldability, and easy scrollability. Particularly, compared with the luminescent film constructed by whisker-like cellulose-based microgel, the hollow cellulose-based fluorescent microsphere film obtained in this work had higher solvent resistance, water contact angle, and thermal stability. Due to the high stability and easy processability of hollow cellulose-based fluorescent microspheres, they could be processed into coating materials and fibers that were durable and widely used. They have potential application value in the fields of light-emitting devices, safety warnings, smart labels, and anti-counterfeiting materials, etc.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
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IF 4.939
Hongmei Zhao,Tingting Zhang,Dongyu Shan,Ying Zhu,Ge Gao,Ye Liu,Jing Liu,Meiying Liu,Wansheng You
An intervening barrier for photocatalytic water decomposition and pollutant degradation is the frustratingly quick recombination of e − - h + pairs. Delicate design of heterojunction photocatalysts by coupling the semiconductors at nanoscale with well-matched geometrical and electronic alignments is an effective strategy to ameliorate the charge separation. Here a facile and environment-friendly l -cysteine-assisted hydrothermal process under weakly alkaline conditions is demonstrated for the first time to fabricate ZnIn 2 S 4 /In(OH) 3 hollow microspheres with intimate contact, which are verified by XRD, SEM, (HR)TEM, XPS , N 2 adsorption-desorption, UV–Vis DRS and photoluminescence spectra. ZnIn 2 S 4 /In(OH) 3 heterostructure (L-cys/Zn 2+ = 4, molar ratio) with a band-gap of 2.50 eV, demonstrates the best photocatalytic performance for water reduction and MB degradation under visible light, outperforming its counterparts (In(OH) 3 and ZnIn 2 S 4 ). The excellent activity of ZnIn 2 S 4 /In(OH) 3 heterostructure arises from the intercrossed band-edge positions as well as the unique hollow structure with large surface area and wide pore-size distribution, which are beneficial for the efficient charge migration from bulk to surface as well as at the interface between ZnIn 2 S 4 and In(OH) 3 . This work provides an efficient and eco-friendly strategy for one-pot synthesis of heterostructured composites with intimate contact for photocatalytic application.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Fanyong Yan,Yao Wang,Chunhui Yi,Jinxia Xu,Bowei Wang,Ran Ma,Ming Xu
The composition of composite photocatalysts with both broad spectral response and efficacious separation of photoinduced carriers were essential. The CDs were installed on the surface of the three-dimensional hollow microsphere nanophotocatalyst Bi 2 WO 6 by the hydrothermal approach. Crystal structure, morphology and composition revealed the synthesis of the composite catalyst. The higher photocatalytic capability of 0.5% CDs/Cl–Bi 2 WO 6 (0.0317 min −1 ) was observed in the degradation procedure, explained that the doping of Cl and the presence of CDs remarkably strengthened the visible light capture and depressed the rate of electron-hole pair complexation. Notably, scavenger-quenching assays results verified that activities of h + , •OH and •O 2 ‾ were the primary actors in the degradation procedure. Ultimately, the degradation mechanism of a feasible TCH was submitted. This study presented a novel concept for the exploitation of composite nanophotocatalysts for the effective degradation of organic pollutants.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Micromachines
·
2024
·Vol. 15
·期 1
·109
·
IF 3
Hao Wu,Juzheng Chen,Tianyi Jiang,Wenlong Wu,Ming Li,Shanguo Zhang,Ziyong Li,Haitao Ye,Mengya Zhu,Jingzhuo Zhou,Yang Lu,Hongyuan Jiang
Hollow microspheres as the filler material of syntactic foams have been adopted in extensive practical applications, where the physical parameters and their homogeneity have been proven to be critical factors during the design process, especially for high-specification scenarios. Based on double-emulsion droplet templates, hollow microspheres derived from microfluidics-enabled soft manufacturing have been validated to possess well-controlled morphology and composition with a much narrower size distribution and fewer defects compared to traditional production methods. However, for more stringent requirements, the innate density difference between the core–shell solution of the double-emulsion droplet template shall result in the wall thickness heterogeneity of the hollow microsphere, which will lead to unfavorable mechanical performance deviations. To clarify the specific mechanical response of microfluidics-derived hollow silica microspheres with varying eccentricities, a hybrid method combining experimental nanoindentation and a finite element method (FEM) simulation was proposed. The difference in eccentricity can determine the specific mechanical response of hollow microspheres during nanoindentation, including crack initiation and the evolution process, detailed fracture modes, load-bearing capacity, and energy dissipation capability, which should shed light on the necessity of optimizing the concentricity of double-emulsion droplets to improve the wall thickness homogeneity of hollow microspheres for better mechanical performance.
研究领域:
材料科学
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力学
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DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 10
·期 3
·1547-1559
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IF 12.732
Ran Liu,Gaiping Du,Bin Liao,Weixin Xiao,Zhenguo An,Jingjie Zhang
Due to their multiple dissipation mechanisms, low density and easily tailored impedance matching, heterogeneous hollow structures are promising candidates for microwave absorbents towards wideband absorption and lightweight design. In this work, a new type of hollow microspheres with a porous carbon shell embedded with crystalline FeCo alloy nanoparticles have been prepared via a stepwise spray drying–calcination strategy. The effects of both the FeCo/C molar ratio and the calcination temperature on the structure and property of the porous hollow microspheres (PHMs) have been studied. It is found that the effective absorption bandwidth of the as-prepared FeCo/C PHMs surpassed 7.44 GHz at a matching thickness of 2.64 mm, which covers the full Ku-band. Moreover, with an elevated calcination temperature, high microwave absorbing performance can be achieved at a much reduced matching thickness. A probable absorbing mechanism has been proposed involving the synergistic effect of the hollow interior, the porous shell structure, and the electric and magnetic dissipation due to the coexistence of carbon and magnetic metals. This work opens a new pathway to synthesize microwave absorbents with a heterogeneous hollow structure, and may shed some light on the design and controlled preparation of other hollow structures with various shell compositions.
研究领域:
材料科学
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电磁学
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DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 99
·97129-97136
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IF 3.289
Wen-Bei Yu,Zhi-Yi Hu,Ming Yi,Shao-Zhuan Huang,Dai-Song Chen,Jun Jin,Yu Li,G. Van Tendeloo,Bao-Lian Su
Transition metal oxides with exposed highly active facets have become of increasing interest as anode materials for lithium ion batteries, because more dangling atoms exposed at the active surface facilitate the reaction between the transition metal oxides and lithium. In this work, we probed the electrochemical behavior of hollow Cu2O microspheres with {111} and {110} active facets on the polyhedron surface as anodes for lithium storage. Compared to commercial Cu2O nanoparticles, hollow Cu2O microspheres with {111} and {110} active facets show a rising specific capacity at 30 cycles which then decreases after 110 cycles during the cycling process. Via advanced electron microscopy characterization, we reveal that this phenomenon can be attributed to the highly active {111} and {110} facets with dangling “Cu” atoms facilitating the conversion reaction of Cu2O and Li, where part of the Cu2O is oxidized to CuO during the charging process. However, as the reaction proceeds, more and more formed Cu nanoparticles cannot be converted to Cu2O or CuO. This leads to a decrease of the specific capacity. We believe that our study here sheds some light on the progress of the electrochemical behavior of transition metal oxides with respect to their increased specific capacity and the subsequent decrease via a conversion reaction mechanism. These results will be helpful to optimize the design of transition metal oxide micro/nanostructures for high performance lithium storage.
研究领域:
材料科学
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电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 34
·14071-14081
·
IF 0
Zhong-Jie Jiang,Zhongqing Jiang
Nitrogen-doped hollow graphene microspheres (NHGSs), synthesized through a procedure involving the calcination of graphene–oxide-wrapped amine-functionalized mesoporous silica nanoparticles (AFMSNs) and the subsequent removal of the AFMSNs via HF etching, have been employed as an electrocatalyst for the oxygen reduction reaction (ORR). It has been shown that these NHGSs are highly active toward ORR and exhibit higher electrocatalytic activity than graphene, nitrogen-doped graphene (NG), hollow graphene microspheres (HGSs), and JM Pt/C 40 wt%, and a comparable overpotential to JM Pt/C 40 wt%. Their high electrocatalytic activity could be attributed to the N-doped graphitic structure, which produces more active sites for the ORR, allowing the easier adsorption of oxygen and the subsequent reduction; and the specific microspherical hollow structure, which promotes the exposure of more surface area accessible to electrolytes, thereby allowing an easier diffusion of electrolytes into and out of the electrode catalyst layers. Their low overpotential for the ORR can be attributed to the specific microspherical hollow structure, which reduces the overpotential contribution from the mass transport limitation. The stability measurements show that NHGSs also exhibit a much higher stability than graphene, NG, HGSs, and JM Pt/C 40 wt%, and are immune to the methanol crossover and CO poisoning effects, which all together makes NHGSs highly attractive as an electrocatalyst for the ORR.
研究领域:
材料科学
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电化学
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产品关联
DOI
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Lina Ma,Guohong Wang,Chuanjia Jiang,Helin Bao,Qingchuan Xu
Core-shell composites with titanium dioxide (TiO 2 ) hollow microsphere as the core and graphitic carbon nitride (g-C 3 N 4 ) as the shell were fabricated via a two-step self-assembly procedure with the assistance of ultrasonic dispersion. The as-prepared composite samples with different g-C 3 N 4 contents (0–20%) were thoroughly characterized and the photocatalytic activity was evaluated by the photocatalytic degradation of Rhodamine B (RhB) in aqueous solution under visible light. A g-C 3 N 4 layer of approximately 80 nm was successfully coated on the surface of TiO 2 hollow microspheres with a diameter of 1–3 μm, forming a heterostructure with close interfacial contact. The TiO 2 @g-C 3 N 4 composite exhibited significantly enhanced photocatalytic activity as compared with pure TiO 2 hollow microspheres. At an optimum weight ratio of g-C 3 N 4 to TiO 2 (15 wt.%), the photocatalytic activity of the composite sample was almost 3 times higher than that of reference TiO 2 hollow microspheres. Moreover, the results of recycling test indicated that the TiO 2 @g-C 3 N 4 composite had excellent stability. A possible photocatalytic reaction mechanism of TiO 2 @g-C 3 N 4 composite was proposed, in which superoxide radical anions played the major role in the oxidation of RhB, and the separation of photogenerated charge carriers across the heterostructure interface inhibited electron-hole recombination, thus enhancing the photocatalytic activity.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）