Nanomaterials
·
2024
·Vol. 14
·期 20
·1629
·
IF 4.4
Penghui Lei,Qing Chang,Mingkun Xiao,Chao Ye,Pan Qi,Fangjie Shi,Yuhua Hang,Qianwu Li,Qing Peng
A new type of SiCf/TiC-Ti3SiC2composite was prepared by the Spark Plasma Sintering (SPS) method in this work. The phase transformation and interface cracking of this composite under ion irradiation (single Xe, Xe + He, and Xe + He + H ions) and subsequent annealing were analyzed using transmission electron microscopy (TEM), mainly focusing on the interface regions. Xe ion irradiation resulted in the formation of high-density stacking faults in the TiC coatings and the complete amorphization of SiC fibers. The implanted H ions exacerbated interface coarsening. After annealing at 900 °C for 2 h, the interface in the Xe + He + H ion-irradiated samples was seriously damaged, resulting in the formation of large bubbles and cracks. This damage occurred because the H atoms reduced the surface free energy, thereby promoting the nucleation and growth of bubbles. Due to the absorption effect of the SiCf/TiC interface on defects, the SiC fiber areas near the interface recovered back to the initial nano-polycrystalline structure after annealing.
研究领域:
材料科学
·
核材料
·
复合材料
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2018
·
IF 0
Shanshan Jie,Congqiang Yang,Yuan Chen,Zhigang Liu
The highly dispersed active sites are desirable to optimize the atom efficiency. In this study, a series of novel cobalt grafted in N-doped carbon (Co-N-C) catalysts for selective oxidation of ethylbenzene are synthesized by heating a solution of cobalt porphyrin and peptides in ionic liquids, which are also characterized by techniques such as FT-IR, XRD, SEM-EDX, HR-TEM, and XPS. The results show that the as-prepared catalysts have an attractive catalytic performance, namely, 40% of ethylbenzene conversion and 75% of selectivity to acetophenone. Especially, the activity and selectivity of the as-prepared catalysts remain almost similar even after the 10th run. Moreover, the modified-complexometry method is verified to improve the dispersion of metal active sites. The remarkable catalytic performance of the as-prepared catalysts is attributed to the highly dispersed active sites and strong interactions between Co and N species in Co-N x moieties.
研究领域:
催化
·
材料科学
·
化学工程
·
分析化学
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产品关联
DOI
FUEL PROCESSING TECHNOLOGY
·
2018
·
IF 3.956
Qilei Yang,Ang Cao,Na Kang,Kang An,Zhao-Tie Liu,Yuan Liu
The catalyst for direct ethanol synthesis (DES) from syngas was investigated in this work, which is Co/La 2 O 3 -doped La 4 Ga 2 O 9 . The catalyst was prepared by using LaCo 1−x Ga x O 3 with perovskite phase as the precursor to intensify the interaction in the elements of Co, La and Ga. The catalysts were characterized by using XRD , H 2 -TPR, TEM , EDS, XPS , BET, ICP and TG techniques. This catalyst showed high selectivity to ethanol and excellent stability including excellent resistance to sintering and carbon deposition . It seems that the ethanol is generated in the interface between metallic Co and La 4 Ga 2 O 9 , and in the interface cobalt would be positively charged due to the interaction between Co nanoparticles and La 4 Ga 2 O 9 . The results and the related discussions indicate that Co/La 2 O 3 -doped La 4 Ga 2 O 9 catalyst is a promising catalyst for DES from syngas. Graphical abstracts.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Qianqian Chen,Xiaobing Yang,Xingping Fu,Junjie Pan,Junmei Zhou,Gengwu Zhou,Kejun Cheng
Currently, antibiotics are extensively utilized in the pharmaceutical industry to assist humans and animals in combating various infectious diseases. The extensive use of various antibiotics enhances the quality of life. However, it can also have negative effects on the environment and human health, including water pollution and the rise of antibiotic-resistant microorganisms. To date, antibiotics have been detected in rivers, groundwater, and even drinking water. There is an urgent need to design and develop advanced materials for the remediation of antibiotics present in our environment. In this paper, we successfully synthesized a novel Ag 2 S-ZnS/ZIF-8 hollow heterojunction via facile sulphuration and solvothermal methods. This heterojunction was employed as a catalyst for the degradation of tetracycline (TC) in water under UV and visible light irradiation. The physicochemical properties of the as-synthesized catalysts were thoroughly analyzed using XRD, EDS, SEM, BET, XPS, TEM, ESR, UV–vis techniques. The results demonstrate that Ag 2 S-ZnS/ZIF-8 displays enhanced photocatalytic activity for TC degradation no matter under visible or UV light irradiation. After 10 min of UV light irradiation, its photocatalytic degradation efficiency was achieved 92.74 %. Additionally, Ag 2 S-ZnS/ZIF-8 was able to degrade 92.14 % of TC (visible light, with 35 min). The corresponding kinetic rate constant of Ag 2 S-ZnS/ZIF-8 is 0.145 min −1 (UV light) and 0.043 min −1 (visible light), respectively. Furthermore, Ag 2 S-ZnS/ZIF-8 also shown excellent stability for the degradation of TC in the presence of visible light. This is a result of its high specific surface area, superior photocurrent and efficient separation of photo-generated electrons-hole pairs. Apart from this, the photocatalytic degradation mechanism of TC over Ag 2 S-ZnS/ZIF-8 is discussed in detail.
研究领域:
环境科学
·
材料科学
·
化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Xiaoping Wu,Qiao Zhang,Lungang Chen,Qiying Liu,Xinghua Zhang,Qi Zhang,Longlong Ma,Chenguang Wang
The development of thermally stable Pt-based catalysts with superior performance for propane dehydrogenation reactions remains a daunting challenge. In this study, a series of PtSn-Mg(Zn)AlO catalysts with different Zn and Pt contents were synthesized by the anion-exchange method for the propane dehydrogenation reaction. To investigate the influence of Zn on the reaction performance and the catalyst structure, the prepared catalysts were characterized with several analytical techniques, including XRD , TEM, HRTEM, H 2 -TPD and CO pulse chemisorption . A good propane conversion (initially higher than 55% and averaging 45.2% over a period of 2 h) and propene selectivity (higher than 99%) were obtained experimentally with PtSn-Mg(3Zn)AlO at 550 °C. The results demonstrated that Pt provided the active sites and that Zn was a promoter. The HRTEM and CO pulse chemisorption results indicated that the addition of Zn to the PtSn-MgAlO catalyst can stabilize the dispersion of metal particles and thus inhibit the sintering of Pt particles. Furthermore, the activities of the used catalysts were almost recovered through reaction-regeneration cycles with the burning-off of coke during five cycles.
研究领域:
催化
·
化工
·
材料科学
✓ 已验证
DOI
高影响因子
ChemistrySelect
·
2025
·Vol. 10
·期 27
·e01710
·
IF 2
Jialu Ju,Xingyu Liang,Yongxin Tao,Weiming Zhang,Shan Li
Graphical Fluorescent CQDs and N-CQDs are prepared via a facile hydrothermal process using dried mulberry (fruit of Morus nigra L.) aqueous extract as the carbon precursor, with urea as the nitrogen dopant for N-CQDs. Their markedly enhanced antibacterial performance is attributed to their higher production of ROS under illumination, especially ·O2− and ·OH. Carbon quantum dots (CQDs) have attracted significant interest due to their intriguing physicochemical properties, and those derived from natural sources can inherit traits of the source material. Here, we report a facile one-step hydrothermal synthesis of fluorescent CQDs and nitrogen-doped CQDs (N-CQDs) using dried mulberry (fruit of Morus nigra L.) aqueous extract as the carbon precursor, with urea as the nitrogen dopant for N-CQDs. X-ray photoelectron spectroscopy (XPS) confirmed that N-CQDs contained a higher nitrogen and a lower oxygen content, compared with CQDs. Transmission electron microscopy (TEM) revealed spherical nanoparticles with diameters of 0.5–4.5 nm for CQDs and 1.2–2.6 nm for N-CQDs. CQDs exhibited concentration-dependent photoluminescence, shifting from strong blue to green emission, whereas N-CQDs consistently showed intense blue emission. In photodynamic antibacterial tests against Escherichia coli and Staphylococcus aureus , CQDs had a minimum inhibitory concentration (MIC) of 0.48 mg/mL after 1 h of 400–410 nm illumination, whereas N-CQDs had an MIC of only 0.06 mg/mL at 450–460 nm. This markedly enhanced antibacterial performance of N-CQDs is attributed to their higher production of reactive oxygen species (ROS) under illumination, especially superoxide radical (·O 2 − ). Therefore, this process can expand the potential application of mulberry, enabling deeper exploitation.
研究领域:
纳米技术
·
材料科学
·
光动力治疗
·
抗菌应用
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Xuesheng Liu,Xueli Li,Xuewei Liu,Sisi He,Junsu Jin,Hong Meng
To improve the photocatalytic performance of ZnO nanoparticles , based on the collective effect as electron sink of Ag and perfect two-dimensional (2-D) feature of graphene, Ag-ZnO-rGO nanoparticles were prepared by polyvinyl alcohol assisted freeze-drying and subsequent hydrothermal reduction method. Through photocatalytic degradation of methyl orange solution under UV irradiation , all as-prepared samples were assessed and compared with those of published works. The surface morphology , microstructure and optical property of materials were systematically studied by XRD , XPS , SEM , TEM and DRS , respectively. XPS and Raman spectra results confirmed that GO has successfully been reduced to rGO; SEM and TEM characterizations manifested that Ag-ZnO NPs were uniformly distributed in rGO with two-dimensional sheets structure; DRS characterization and Kubelka-Munk formula calculation illustrated that Ag-ZnO-rGO exhibited the smallest band gap and the best optical absorption performance. Moreover, the photocatalytic degradation results indicated that Ag-ZnO-rGO NPs combine the advantages of graphene and Ag which not only has significant adsorption but also maintains high photoreactivity.
研究领域:
材料科学
·
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2019
·
IF 3.78
Tian Liu,Xingrong Zeng,Xuejun Lai,Hongqiang Li,Yanlin Wang
Organosilicon materials with high capacity of organic-to-inorganic conversion at elevated temperature are always favorable in the field of high-temperature-resistant materials, flame retardant materials, chemical engineering and functional materials in electrical engineering. In this work, it was found out that the platinum-nitrogen catalytic system could obviously enhance the organic-to-inorganic conversion efficiency of silicone rubber (SiR) at elevated temperature. The residual rate of Pt/N/SiR (SiR containing 0.33 phr Karstedt's catalyst (Pt) and 2 phr nitrogenous silane (N)) at 1000 °C was significantly improved from 3.0% to 44.8% in comparison with SiR and its thermal stability was also enhanced. DLS , TEM and UV–vis absorption spectrometry revealed that the platinum in Karstedt's catalyst would aggregate at elevated temperature and deteriorate its catalytic activity for organic-to-inorganic conversion of SiR. And the addition of nitrogenous silane can efficiently inhibit the aggregation and retain the high catalytic efficiency of platinum. A thorough TG-FTIR study, together with SEM/EDX and XPS analyses suggested that the platinum-nitrogen system might suppress the intramolecular cyclic transition and enhance the radical coupling between polymer chains of SiR during thermal degradation , which resulted in the high capacity of organic-to-inorganic conversion of Pt/N/SiR at elevated temperature.
研究领域:
材料科学
·
化学工程
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 32
·21882-21889
·
IF 3.9
ManLu Wang,JiaCheng Wu,LiYing Hao,Qiang Wei
Herein, a facile method is proposed for the bulk synthesis of conductive non-metallic carbon nanospheres with controllable morphology to replace conventional metal calibration reference materials (CRMs), such as gold nanoparticles and copper grids. The prepared nanospheres had an average diameter of ∼222 ± 23 nm, where silicon dioxide formed the core and the shell was comprised of the carbon layer. The structure of the conductive carbon nanospheres was characterized using FTIR, SEM, EDS and TEM. Additionally, an innovative design was demonstrated by 3D printing the calibration carrier device. Furthermore, the stability and image linear distortion of the conductive carbon nanospheres were verified using analysis of variance (ANOVA). The results demonstrated that the accelerating voltage, magnification, and various positions in the X/Y axes had no significant effect on measured diameter of nanospheres, which was evident from all the p values being greater than 0.05. The comprehensive set of results reveal that conductive carbon nanospheres have great potential to replace traditional CRMs.
研究领域:
材料科学
·
纳米技术
·
显微镜技术
·
3D打印
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2013
·
IF 2.39
Xiong Song,Qiang Ru,Beibei Zhang,Shejun Hu,Bonan An
A novel flake-by-flake ZnCo 2 O 4 (ZCO) with porous nanostructure is prepared by a typical and facile co-precipitation method using oxalic acid as complex agent. XRD, SEM, and TEM analyses show the as-prepared ZCO nanoparticles have a high purity and a good crystallinity, and the ZCO nanoflakes with a thickness of 30–80 nm are composed of uniform ZCO nanocrystals with a diameter of 20–40 nm. The novel structure with enough free space is beneficial to improving the electrochemical performance. The as-prepared ZCO used as an anode material for lithium-ion batteries exhibits a high specific capacity of 1275 mA h/g at a current rate of 100 mA/g after 50 cycles, as well as a high power capability at elevated current rates, i.e., 1130 and 730 mA h/g at current rates of 500 and 3000 mA/g, respectively. It has a great prospect for the application of anode materials for lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
纳米技术
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
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
·
材料科学
·
化学
✓ 已验证
产品关联
DOI
COLLOID AND POLYMER SCIENCE
·
2015
·Vol. 293
·期 9
·2625-2634
·
IF 1.865
Li Ping,Yang Xiaoyi,Guo Chaohua,Wang Guoyong,Zhang Wei
The adsorption and aggregation behavior of three tetrasiloxane surface active room temperature ionic liquids, N -(2-aminoethyl)-3-aminopropyltetrasiloxane carboxylic acid ammonium, [Si(4)N(2)-2CA(n) ( n = 1, 2, 3)], have been studied on the basis of static/dynamic surface tension, conductivity, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The static surface tension of the Si(4)N(2)-2CA(n) aqueous solutions measured at the critical aggregation concentration (CAC) is observed to be significantly lower than that of amide-functionalized ILs and is comparable to those reported for trisiloxane RT-SAILs, N -(2-aminoethyl)-3-aminopropyltrisiloxane carboxylic acid ammonium and 3-aminopropyltrisiloxane carboxylic acid ammonium. The dynamic surface tension results indicate that adsorption process is a mixed diffusion-kinetic adsorption mechanism. DLS and TEM analysis of Si(4)N(2)-2CA(n) solutions reveal that they can self-assemble into vesicles with an average diameter in the range of 70–500 nm.
研究领域:
化学
·
材料科学
·
胶体与界面化学
✓ 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）