Optoelectronics Letters
·
2014
·Vol. 10
·期 3
·164-167
·
IF 0
Yang Ai-ling,Li Shun-pin,Wang Yu-jin,Bao Xi-chang,Yang Ren-qiang
By adjusting pH values of reactant system, the mass ratio of stabilizer/water and aging temperature, size controllable spherical silver nanoparticles (NPs) were synthesized. The properties of silver NPs are characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and ultraviolet visible (UV-VIS) absorption spectra. Within the pH values of 7.0–11.0, the aging temperature of 80 °C is better to improve silver NPs in shape to nearly sphere, concentrate size distribution and reduce aggregation than the aging temperature of 25 °C. The shape and dispersibility of silver NPs are the best when the pH of the reactant system is within 7.0–8.0. With pH of 7.5, aging at 80 °C, and stabilizer/water mass ratio of 1%, the spherical silver NPs with sizes of 50–70 nm were synthesized. The results are promising to be used to synthesize core/shell NPs when silver NPs are as core.
研究领域:
纳米技术
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材料科学
·
化学
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产品关联
DOI
CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Yuyang Wu,Xincheng Jiang,Jiangya Ma,Jingbo Wen,Shuang Liu,Hongxia Liu,Huaili Zheng
A kind of starch-based flocculant (starch- graft -poly[(2-methacryloyloxyethyl) trimethyl ammonium chloride], denoted St-g-PDMC-LPUV) has been synthesized by low-pressure ultraviolet initiation and was employed to remove humic acid (HA) for water purification . The physicochemical characteristics of starch and St-g-PDMC-LPUV were characterized by FT-IR, 1 H NMR, XRD, TGA , SEM and BET to confirmed the successful grafting DMC onto starch. Effects of flocculant dosage, pH, the adding amount of Fe 3 O 4 , initial HA concentration and stirring speed were investigated systematically. The prepared St-g-PDMC-LPUV flocculant with non-toxic, biodegradability and environmental friendliness exhibited effective performance for removing HA from water in a wide pH range (5–10). The flocculation mechanism was attributed to the effective collision between function groups of the St-g-PDMC-LPUV flocculant and HA by charge neutralization, adsorption, bridging and patching.
研究领域:
环境科学
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化学工程
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材料科学
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Yanliang Zhai,Yunshan Shang,Luoming Zhang,Xiaoling Meng,Yanjun Gong,Lirong Zheng,Jing Zhang,Ping Liu
Hydrothermally modified nanosheet ZSM-5 zeolite by directly using MnO x nanoparticles was carried out and this substantially offered a high performance catalyst for methanol to propylene (MTP) reaction. The properties of as synthesized ZSM-5 nanosheets with different MnO x amounts (NS-x) were compared with ZSM-5 nanosheets modified by impregnation method (IM-0.5) and physically mixed method (PM-0.5), respectively. The initial state of MnO x nanoparticles was close to Mn 2 O 3 with 20 nm in size. XRD , H 2 -TPR and XAFS results confirmed under high temperature hydrothermal condition, the Mn 2 O 3 nanoparticles disaggregated into Mn 2 O 3 clusters and entered the framework defects of nanosheet zeolite with high dispersion. Infrared spectra of hydroxyl groups (OH-IR) showed that the Mn 2 O 3 clusters were bonded with silanol defects both on the surface and inside zeolite, which substantially increased the stability of Mn 2 O 3 clusters and healed the framework defects. In contrast, the Mn species in the impregnated sample was close to the co-existence of Mn 2+ ions and MnO 2 nanoparticles with 2–3 nm, no interaction between Mn species and Si–OH group was determined. Notably, the typical sample (NS-0.5) with MnO x cluster modification performed much higher propylene selectivity and catalytic stability (~52%, 240 h, WHSV = 3 h −1 ), while the conventional IM-0.5 and PM-0.5 showed poor propylene selectivity (48%, 46%) and catalytic stability (166 h, 133 h) in MTP reaction. The excellent result should be attributed to the subtle control of external strong acid and the less structural defects, due to specific existence of bonded Mn 2 O 3 clusters.
研究领域:
化学
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材料科学
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催化
·
纳米技术
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Kun Jiang,Kun Liu,Qian Peng,Muyang Zhou
Montmorillonite (MMT) and humus have a good adsorption effect on heavy metal ions . This study proposed a synthetic method for a novel composite of humus-like substances/MMT (HLS-MMT) by introducing humus precursors into the interlayer domain of MMT and then forming HLS through in situ catalytic polycondensation reaction. The structure and morphology of samples were characterized by XRD , FTIR, and SEM , which demonstrated the successful loading of HLS on the internal and external surfaces of MMT. The experimental results showed that the loading of HLS on MMT was very stable, and the adsorption capacity of the modified MMT for lead and zinc ions was greatly enhanced. The effects of single-factor experiments showed that the pH value was the key factor affecting the adsorption process . In addition, the adsorption process was found to be in good agreement with the Langmuir isotherm model and the pseudo-second-order kinetic model . The competitive adsorption experiment displayed that HLS-MMT had a higher affinity for Pb ions than Zn ions, and the cycling experiment presented that the adsorbent had good regeneration and cycling performance. This study shows that HLS-MMT is a novel adsorbent with a good capacity to separate and enrich Pb and Zn ions similar to ion-exchange resin.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 18
·53355-53369
·
IF 5.8
Ding Chunsheng,Lei Jia,Cai Zhiyue,Gao Mengying,Zou Zhaozheng,Li Yuanfeng,Deng Jing
In this research, FeCo 2 O 4 nanomaterial was successfully synthesized by a typical sol–gel method and conducted as an effective agent for peroxymonosulfate (PMS) activation to eliminate antibiotics flurbiprofen (FLU), a strong nonsteroidal drug. FeCo 2 O 4 nanomaterial was characterized by XRD, TEM, SEM, and XPS. Various characterization results proved that FeCo 2 O 4 held stable spinel structure. The interfering factors including initial pH, PMS concentration, catalyst dosage, inorganic anions, and humic acid on FLU removal were also discussed. The conclusion was that the removal efficiency of FLU reached 98.2% within 120 min after adding FeCo 2 O 4 (0.4 g L −1 ) and PMS (3 mM). The optimal pH for FLU degradation was the initial pH of 6.5; too acidic or alkaline was not conductive to the degradation. The existence of HA and Cl − restrained the degradation of FLU, and HCO 3 − promoted the removal, while the influence of NO 3 − and SO 4 2− could not be considered. The radical scavenging experiment confirmed that • OH, O 2 •− , and SO 4 •− participated in FLU removal and SO 4 •− functioned a leading role. FeCo 2 O 4 showed high efficiency for PMS activation in pH range of 3.0 to 10.0. After the fourth cycle operation, the FLU removal rate exceeded 76.9%, and the Co leaching rate was low during the catalytic reaction. This study shows that FeCo 2 O 4 nanomaterial is an efficient and environment-friendly catalyst, which can be applied for PMS activation to remove organic pollutants in water.
研究领域:
环境科学
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化学
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材料科学
·
水处理
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Xiaohui Wu,Qin Zhang,Fangyi Huang,Xingyu Huo,Fuyu Li,Yulan Jing,Yuanxun Li,Hua Su
In this work, a new low loss Ba 3 Ti 4- x (Mn 1/3 Nb 2/3 ) x Nb 4 O 21 (MN-BTN, 0 ≤ x ≤ 12 mol%) ceramics configuration was presented through preparing by the solid-state route. The XRD patterns, Rietveld refinement , microstructure, and microwave properties were systematically analyzed. All the fabricated MN-BTN ceramics belonged to the hexagonal structure with a P 6 3 / mcm space group. More specifically, the 6MN-BTN ceramic exhibited a high relative density of ~92.3 %, homogeneous grains distribution with an average size of ~71.95 µm, and several excellent microwave dielectric properties : ε r = 59.67, Q× f = 16,226 GHz, τ f = +103.9 ppm/℃ sintered at 1220 ℃. The incorporation of 1.5 wt % BaCu(B 2 O 5 ) (BCB) compound within the 6MN-BTN ceramic not only effectively reduced the sintering temperature from 1220 ℃ to 950 ℃, but also the excellent microwave dielectric properties were maintained: ε r = 42.33, Q× f = 11,300 GHz, τ f = +24.7 ppm/℃. Interestingly, the 6MN-BTN + 1.5 wt % BCB ceramic showed better chemical compatibility with Ag. The proposed 6MN-BTN + 1.5 wt % BCB ceramic configuration could be regarded as a promising material for LTCC applications.
研究领域:
材料科学
·
陶瓷工程
·
微波工程
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Qionghao Wang,Yaqi Peng,Min Chen,Mengxia Xu,Jiamin Ding,Qi Yao,Shengyong Lu
The process of urbanization has resulted in a continuous growth of the production of municipal solid waste , consequently leading to the increase of municipal solid waste incineration fly ash (MSWI FA) over time. This has prompted the need for effective disposal and value-added utilization strategies for MSWI FA. In this study, a hydrothermal method was employed to synthesize Ca Al layered double hydroxides (LDHs) using MSWI FA as the raw material. The main objective was to investigate how different synthesis parameters affect the crystallinity of the layered bimetallic hydroxides. Subsequently, the synthesized LDHs were characterized using various techniques such as BET, SEM , XRD, FT-IR, and XPS. The results revealed the presence of calcium and aluminum cations in the interlayer region of the synthesized material, with chloride ions, sulfate ions, and acetate ions being the predominant anions. Moreover, the formation of LDHs presents an effective approach for the self-purification of leachates derived from MSWI FA. The LDHs exhibited excellent adsorption capacity for Cd 2+ and Cu 2+ in wastewater, with maximum values of 730 mg·g −1 and 446 mg·g −1 , respectively. The adsorption mechanisms involved isomorphous substitution, complexation, as well as the precipitation of hydroxides or interlayer anions. This method presents a novel approach for effectively utilizing MSWI FA to produce environmentally friendly value-added adsorbents.
研究领域:
环境科学
·
废物管理
·
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Yuchun Ji,Zhengde Li,Laiping Zhang,Jilin Wang,Wenbiao Li,Wenzhuo Chen,Guoyuan Zheng,Fei Long,Zhengguang Zou
In this paper, a novel boron nitride hollow microtube (BNHM) structure by annealing assisted high-pressure etching method. The products were characterized by XRD , FTIR, Raman, XPS , SEM, TEM, TGA , BET, UV–vis, and PL. The result shows that the sample displayed a one-dimensional hollow tube structure directionally covered with nanosheets . The average inner diameter of the hollow tube is 1 µm with a length of 2–4.5 µm. And the wall thickness of the hollow tube structure is about 100 nm. In addition, the band gap value of the sample is 5.51 eV presenting the strongest absorption peak at 225 nm. The specific surface area of the sample is 272.6 m 2 ·g −1 , showing good adsorption efficiency on Congo red (absorbed 75% in 5 min). Meanwhile, the possible growth mechanism of BNHM is also discussed.
研究领域:
材料科学
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纳米技术
·
化学
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
Science of Advanced Materials
·
2017
·
IF 1.671
Zhou Zhiping,Yu Yingsen,Sun Quanmin,Liu Xiaotang,Lei Bingfu,Yan Yun
In this work, up-conversion phosphor CaF2:Yb3
+, Er3+ was synthesized by the co-precipitation method. X-ray Diffraction (XRD) and Photoluminescence Spectra (PL) were used to characterize the samples. The effects of annealing temperature and
Yb3+ and Er3+ concentrations on the luminescence properties were discussed. Strong green and red light were obtained under 980 nm laser excitation, the optimal annealing temperature was 600 °C, while the optimal doping concentration was 8 mol% Yb3+ and
0.6 mol% Er3+. The green (540 nm and 552 nm) and red (652 nm and 669 nm) up-conversion luminescence peaks can be ascribed to the transitions of 4S3/2-4I15/2 and 4F9/2-4I15/2, respectively. The
up-conversion luminescence intensities of the green and red emitting peaks can be changed by adjusting the concentration ratio of Yb3+ and Er3+. Hence, it can potentially be used as the red light conversion agent. The dependence of up-conversion intensities (CaF2:Yb3+,
Er3+) on excitation power indicated that two-photon absorption processes were responsible for green and red luminescence.
研究领域:
材料科学
·
光学
·
光子学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
Jinning Wang,Qiufeng Shi,Konstantin V. Ivanovskikh,Lei Wang,Jianwei Qiao,Haijie Guo,Ping Huang
A series of Mn 4+ -doped NaSr 10 Y 5 W 4 O 30 (NSYWO) phosphors have been successfully synthesized and further characterized to estimate their potentials for application as a far-red emitting component of pc-LED. An XRD analysis and crystal structure refinement have been carried out to characterize its quality. The doping concentration and temperature (80–500 K) dependent luminescence properties as well as decay kinetics have been studied and analyzed. It has been found that Mn 4+ substitutes for W 6+ sites resulting in far-red emission at 688 nm. The temperature quenching is attributed to thermal activation of an electron from Mn 4+ 2 E g to 4 A 2g state via crossover, yielding an activation energy of 0.35 eV. Furthermore, to assess practical application of the novel phosphor, a blue-emitting LED chip combined with NSYWO: 0.8 mol% Mn 4+ has been packaged. The light from both the blue-emitting LED chip and NSYWO: Mn 4+ phosphor was shown to be effectively utilized, revealing a good promise for application of the phosphor in the field of plant growth lighting.
研究领域:
材料科学
·
光电
·
植物生物学
·
光子学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Weiqian Song,Yangxi Yan,Maolin Zhang,Dongyan Zhang,Li Jin,Zhimin Li
In this study, Co-doped 0.49 Pb(Ni 1/3 Nb 2/3 )O 3 -0.51 Pb(Hf 0.3 Ti 0.7 )O 3 ceramics with high piezoelectric constants, electromechanical coupling coefficients, and low dielectric losses were prepared by conventional solid-phase reaction method for use as piezoelectric energy harvesters in both resonant and non-resonant working states. XRD results showed the dissolution of Co ions in the crystal lattice , thereby replacing B-sites and transforming the crystal phase into tetragonal phase. Valence states of Co obtained from fitted XPS data confirmed the existence of Co as Co 2+ in the lattice. The introduction of Co 2+ effectively increased grain size, improved ferroelectric properties , reduced leakage current density, and enhanced electromechanical coupling coefficient k p . Impacts of Co-doping on properties of the as-obtained ceramics were discussed. The optimal performances were obtained at x = 1.25, with piezoelectric constant d 33 ~780 pC/N, electromechanical coupling coefficient k p ~0.62, and dielectric loss tan δ = 0.78%. In sum, the excellent piezoelectric properties of Co-doped PNN-PHT ceramics look promising for use as piezoelectric energy harvesters.
研究领域:
材料科学
·
陶瓷
·
压电材料
·
能量收集
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2022
·Vol. 26
·期 4
·917-927
·
IF 2.747
Zhang Lang,Chang Shiying,Lu Xingjie,Han Tao,Jin Ruoheng,Zhao Tenglong,Fang Dong,xie Ming,Wang Mingjun,Yi Jianhong
Vanadate-based synthesis of battery electrodes has become a topic of research interest due to the high lithium storage performance. However, the rapid capacity decay seriously hinders its practical application. In order to improve the potential for Co 3 V 2 O 8 (CVO) as an electrode in lithium batteries, a Na 5 V 12 O 32 nanowire precursor with a smooth surface was obtained using the hydrothermal method. Next, the CVO nanowires assembled by nanosheets were fabricated by cation exchange from the Na 5 V 12 O 32 precursor. Finally, the elemental phosphorus-coated CVO was successfully synthesized by a custom furnace. The characterization of X-ray diffraction (XRD) and inductively coupled plasma emission spectroscopy (ICP-ES) quantified the ratio of P and CVO, and Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) revealed the presence and coverage. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) further demonstrated the existence and morphology of P and CVO. Meanwhile, electrochemical measurements illustrated the stable lithium storage and notable rate performance of the P-CVO electrode as compared to AN-CVO. The P-CVO electrode holds a higher stable cycle performance after 190 cycles, with discharge specific capacity of 415.3 mA h g −1 and capacity retention of 97% at a current density of 1.0 A g −1 (872 mA h g −1 , 2.0 A g −1 , 98.8%), versus AN-CVO with 320.6 mA h g −1 (capacity retention of 79.5%) after only 100 cycles. Thence, the synthetic strategy provides a potential solution to enhance the stability of electrodes for high-performance lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
能量存储
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）