CRYSTENGCOMM
·
2020
·Vol. 22
·期 8
·1368-1380
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IF 3.117
Hui Zhou,Kaleemullah Kalware,Ming Shen,Songtao Zhong,Yufeng Yao
A series of BiOCOOH and Bi/BiOCOOH heterojunction micro-/nanostructures with various morphologies have been successfully synthesized by a one-step hydrothermal process with the assistance of formamide. The morphology, structure and composition of the as-obtained samples and the effect of formamide were systematically characterized and investigated. The results reveal that formamide plays multiple roles in the synthesis of the BiOCOOH and Bi/BiOCOOH heterojunctions, which acts as the carbon and alkali source. Moreover, the formic acid abundantly provided by the hydrolysis of formamide serves as the reductant and structure-directing agent. The photocatalytic activities of all the catalysts were evaluated by the degradation of rhodamine B (RhB) and reduction of potassium dichromate (K2Cr2O7) under simulated sunlight irradiation. It is found that the photocatalytic activity is closely related to the morphology and composition of the photocatalyst. The well-defined 3D flower-like BiOCOOH prepared at 20 vol% formamide shows a higher photocatalytic activity than the other BiOCOOH samples, which could be attributed to its hierarchical nanostructure, larger specific surface area and stronger adsorption capacity. Meanwhile, the Bi/BiOCOOH heterojunction obtained at 60 vol% formamide shows the best photocatalytic performance due to the increased light absorbance capacity and more efficient separation and transfer of photogenerated carriers with the existence of in situ deposited metallic Bi. Trapping experiments reveal that h+ and ˙O2− are the main active species in the photodegradation process and a possible photocatalytic mechanism is proposed.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Zi-Yu Wang,Wei-Lin Li,Chao-Feng Pan,Yan-Hui Sun,Jun-Min Nan
A series of carbon coated SnFe 2 O 4 (SFO) with octahedron, decahedron and tetrakaidecahedron morphologies have been synthesized by a simple hydrothermal process using ferrocene as common source of iron and carbon, applying a cationic surfactant CTAB to modify the morphology. Compared with the octahedral SFO (no CTAB) and decahedral SFO-0.1 (with CTAB at the first critical micelle concentration (CMC)), the tetrakaidecahedral SFO-0.7 (with CTAB at the second CMC) as an anode of LIB shows a high charge/discharge capacity of 481.0/482.7 mAh g −1 after 1000 cycles at 2 A g −1 , and 281.0/281.6 mAh g −1 after 2000 cycles at 6 A g −1 . The investigations on Li-ions inter-/de-intercalation kinetics show that the main rate-controlled step of SFO-0.7 is pseudocapacitive behavior, with higher contribution of 95.88% at a scan rate of 2.0 mV s −1 . The results suggest that the carbon layer obtained directly from ferrocene can effectively inhibit the volume expansion and structure damage of SnFe 2 O 4 . At the same time, more oxygen-vacancies increase the conductivity, the enhanced strength of the dominant (1 1 1) plane can adsorb Li-ions more easily, and the smaller SnFe 2 O 4 can reduce the diffusion distance of Li-ions, all of which lead to a high and stable Li-ions storage capacity and rate capability.
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 59
·88866-88881
·
IF 5.19
Xia Xuewen,Li Junqi,Chen Chaoyi,Lan Yuan-Pei,Mao Xisong,Chu Zhiyao,Ning Deyang,Zhang Junshan,Liu Fengyuan
Tuning morphology and doping additional rare earth (RE) cations are potential techniques to promote the photocatalytic performance of ceria (CeO 2 ), evaluating the collaborative effects of morphology and RE dopants is significant for producing high active ceria-based catalysts. So in this work, cubic, polyhedral and rod-like nanoceria doped with 10 mol % La (lanthanum), Y (yttrium), or Sm (samarium) were synthesized by a facile template-free hydrothermal method. Phases, morphologies, oxygen vacancies (OVs) concentration, energy band structure, photo-carriers separation/recombination, and photodegradation ratio toward methylene blue (MB) dye of as prepared ceria were studied. Results show that doped CeO 2 maintains a similar morphology structure with un-doped sample and the band gap narrows slightly. Y-doped nanoceria, with an improved separation and a reduced recombination of photo-excited electrons ( e − ) and holes ( h + ), owns a higher MB photodegradation ratio than that of samples doping with La or Sm, which is measured as 79.04, 84.43, and 85.59% for Y-doped cubic, polyhedral, and rod-like CeO 2 . The collaborative influence of morphology tuning and RE (La, Y, and Sm) doping on photocatalytic performance of nanoceria includes the effects of doped elements and the formation of OVs. The elevation of OVs concentration as well as the separation efficiency of photo-generated e − / h + are suggested to further enhance the photocatalytic performance of ceria.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Fei Wang,Li Li,Chaohui Yang,Zhongxing Cai,Ziyi Guo,Siyu Hou,Xiaoya Xie,Yinghao Chen,Jing Huang,Long Zhang
A series of GdPO 4 :5%Eu 3+ micro/nanomaterials with different morphologies and crystal structures were successfully prepared by the one-step solvothermal method using only the gadolinium source, the phosphoric acid source and ethanol as solvents, without any surfactants or templates, without further calcination and by adjusting only the ratio of phosphoric acid and gadolinium sources. They all have good dispersion and homogeneity. The morphology of the products was mainly regulated by the ratio of H 3 PO 4 to Gd(NO 3 ) 3 · 6H 2 O, with ratios of 2:1, 8:1, 16:1, 24:1, 32:1, 40:1 and 48:1 mL/g resulting in the formation of square, pillow, star, carambola, hollow cylinder, drum and jujube shaped GdPO 4 :5%Eu 3+ micro/nanomaterials, respectively. Ratios of 2:1–24:1 and 32:1–48:1 allow for the direct solvothermal synthesis of monoclinic and hexagonal phase gadolinium phosphate, simultaneously. In addition to their crystal structure and morphology, chemical bonding, thermal stability and specific surface area, their luminescence properties and magnetic resonance imaging (MRI) tracing properties have also been studied in comparison. Interestingly, the GdPO 4 :5%Eu 3+ micro/nanoparticles in the carambola shape had a higher photoluminescence intensity and relaxation rate of 0.7709 mM −1 s −1 (r 1 ) among all the morphologies. The possible mechanisms by which various morphologies of GdPO 4 :5%Eu 3+ were prepared in different ratios were analyzed, and the reasons for their effects on the fluorescence and MRI tracer properties were further investigated. This study is of reference significance for the simple-regulated synthesis of rare earth inorganic gadolinium-containing micro/nanomaterials and provides a reliable guarantee for the expansion of their multifunctional applications in UV–Vis luminescence and MRI tracing for implants.
研究领域:
材料科学
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医学影像学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2011
·
IF 2.146
Aifang Geng,Yubing Liu,Wuping Liao
CdS microtrumpets with the length being of about 4 μm and the bell wall being of 100 nm have been prepared using a cadmium di-(2-ethylhexyl) phosphoric acid chelate as the precursor by a two-phase thermal approach. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV–vis spectroscopy. The effects of temperature, reaction time, and co-surfactant on the morphology were also examined. It was found that the co-surfactant triethanolamine plays a crucial role in the formation of the cubic phase trumpet-like CdS microstructures.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2016
·
IF 3.782
Xiaoning Wang,Hongche Chen,Hongjing Li,Gilles Mailhot,Wenbo Dong
BiOCl 0.75 I 0.25 crystals with irregular three-dimensional (3D) flower-like and hierarchical nanosphere-like structures were successfully synthesized in different alcohol–water mixed solvents by precipitation method. The primary formation mechanism of BiOCl 0.75 I 0.25 nanospheres was investigated by taking water, monohydric alcohols (ethanol and isopropanol), and polyhydric alcohols (ethylene glycol, diethylene glycol , and glycerol) as solvents in the synthesis process. The obtained BiOCl 0.75 I 0.25 samples were characterized by powder X-ray diffraction, Raman spectroscopy , field emission scanning electron microscopy , and nitrogen adsorption . Results showed that the alcohol solvents with different physical and chemical properties used in the synthesis process performed significant functions in directing the morphology and surface pore structure of BiOCl 0.75 I 0.25 crystals. Meanwhile, BiOCl 0.75 I 0.25 synthesized in various solvents exhibited morphology-dependent adsorption and photocatalytic degradation abilities in removing p -hydroxyphenylacetic acid ( p -HPA), which was used as a model pollutant, in aqueous solutions under simulated solar light (λ ⩾ 290 nm). In addition, the fabrication process of the crystal products was proposed through a series of time-dependent experiments.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2016
·Vol. 18
·期 31
·5940-5951
·
IF 3.849
Jingjing Cao,Li Yuan,Shanshan Hu,Jianfeng Tang,Xianju Zhou,Jun Yang
Monodisperse ScF3 and NaScF4 nano-/micro-crystals were prepared by a simple solvothermal method. There were many important factors including the molar ratio of Na/F/(Sc + Ln) and Ln3+ doping to control the synthesis of the products. A phase transformation from monoclinic ScF3 to hexagonal NaScF4 was observed with different molar ratios of Na/F/Sc. Herein, the products doped with 1% Ln3+ (La–Lu, except Pm) demonstrated abundant phases, morphologies and sizes. Moreover, the products with different Lu3+ doping concentrations from 1% to 60% were prepared. The results revealed that different kinds of 1% Ln3+ (La–Lu, except Pm) and diverse concentrations of Lu3+ can modify the phase, morphology and size of the prepared products. A possible formation mechanism for the products with diverse morphologies is proposed. In addition, Ln3+-doped ScF3 or NaScF4 nano-/micro-crystals presented characteristic up/down-conversion fluorescence spectra.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2017
·
IF 2.446
Chuan Ding,Xiaoshu Jiang,Xiaohong Huang,Hu Zhang,Wenqing Zhong,Yifei Xia,Chongjiang Dai
Fe 3 O 4 nanocrystals (NCs) composed of different proportion of {100} and {111} facets were prepared using oleic acid and decanoic acid as surfactant to mediate their growth process. It has been found that the morphology of Fe 3 O 4 NCs can be tuned by changing the ratio of oleic acid and decanoic acid. When tested as the anode materials in LIBs, the Fe 3 O 4 octahedrons obtained after annealing at 450 °C was found to exhibit superior electrochemical performances with a high reversible capacity of 882.6 mAh g −1 at 1 A g −1 over 200 cycles, whereas the Fe 3 O 4 cubooctahedron and cubes bearing poor electrochemical performances. The present results prove that the surface structure of Fe 3 O 4 polyhedrons significantly influence the utilization of Fe 3 O 4 active materials and hence their electrochemical performance although the morphology will be destroyed during cycling.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2014
·
IF 2.726
Chuanying Wang,Xianhua Cheng
Using a facile hydrothermal method , hexagonal β-NaYF 4 :Yb 3+ 20 mol%, Er 3+ 1 mol% crystals with predictable size and morphology were synthesized and the upconversion (UC) luminescence properties were investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectra were used to characterize the samples. The results indicated that the size and morphology of the crystals can be precisely controlled by tuning the pH values of the initial reaction solution and the molar ratio of NaNO 3 to RE 3+ (RE = Y + Yb + Er), and the mechanism was proposed. The UC luminescence properties of β-NaYF 4 :Yb 3+ /Er 3+ crystals were found to strongly depend on the crystal morphologies and sizes. The peak area ratio of green to red (R/G) increased from 0.29 to 1.03 with pH values increasing from 3 to 10, and increased from 1.03 to 1.26 with the increase of molar ratio of NaNO 3 to RE 3+ from 0 to 90. The emission colors were tuned from pure green to orange yellow. This study provides a facile way to synthesize β-NaYF 4 :Yb 3+ /Er 3+ crystals with predictable morphology and size, and tunable luminescence properties, which can be applicable for other rare earth fluoride compounds.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 35
·27901-27911
·
IF 3.84
Chunling Xin,Haijuan Zhan,Xin Huang,Hongguang Li,Ning Zhao,Fukui Xiao,Wei Wei,Yuhan Sun
Two type of modulators, including sodium acetate and triethylamine were used to synthesize nanosized HKUST-1 crystals with tailored size and morphology using a coordination modulation method. The results of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and N2 sorption isotherms confirm that the size of the HKUST-1 crystals can be tuned from the micron scale to the nanoscale through precise modulation of the amounts of the modulators. Moreover, hierarchical porous structures are obtained with the addition of modulators. It is suggested that a moderate acid–base environment and capping groups play an important role in controlling the size and morphology of HKUST-1. Dynamic CO2 breakthrough experiments illustrate that the CO2 capacity of nanosized HKUST-1 crystals is superior to that of micron-sized HKUST-1 crystals under low CO2 partial pressure conditions (0.1 bar). Besides, the CO2 adsorption capacity of nanosized HKUST-1 crystals was maintained after ten adsorption/desorption cycles.
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
Results in Chemistry
·
2022
·
IF 0
Deqing Chu,Yundalai Wu,Limin Wang
Bismuth oxide, a widely studied semiconductor material, has been discovered in a variety of forms. Novel coral spherical α-Bi 2 O 3 with a diameter of 2–4 μm was successfully prepared by a simple template-free and surfactant-free hydrothermal method. The structure and morphology of the samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission electron scanning microscopy (FESEM), energy dispersive spectroscopy (EDX) and transmission electron microscopy (TEM). The experimental results revealed that the reaction time and the urea concentration could regulate the morphology of Bi 2 O 3 , and a possible formation mechanism was proposed based on the results. This study provides a new idea for the morphological synthesis of bismuth oxide.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
Reaction Chemistry & Engineering
·
2023
·Vol. 8
·期 5
·1185-1191
·
IF 3.9
Lingjiang Kou,Yong Wang,Jiajia Song,Taotao Ai,Koji Kajiyoshi,Panya Wattanapaphawong,Jintao Wang
Developing a structurally controlled electrode has attracted widespread attention in recent years, which is ascribed to the morphology of cathode materials having an influence on the electrochemical performance. Herein, we present Mn-decorated (NH4)2V10O25·8H2O (NVOH) materials with a cauliflower-like, tremella-like, and purslane-like structure via a solvothermal approach. When examined as a cathode material for aqueous zinc-ion batteries (ZIBs), all three materials with different morphologies exhibited superior electrochemical performances. Especially for materials with a tremella-like structure, benefiting from the uniqueness of the porosity structure of the tremella, the active material has a larger contact area with the electrolyte, which increases the active sites and diffusion coefficient of Zn2+. This tremella-like NVOH delivered a high rate capability of 159 mA h g−1 at 500 mA g−1 together with long-term stability (85% retention after 500 cycles at 500 mA g−1). This study has great significance for the exploitation of cathode electrodes of aqueous ZIBs with high reversible specific capacity and long cycle life and provides a promising candidate cathode for practical rechargeable aqueous ZIBs.
研究领域:
材料科学
·
电化学
✓ 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）