INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jiaming Wang,Huixian Zhong,Kang An,Qiang Liu,Wu Jin,Yuan Liu
In this work, Ni–Co alloy nanoparticles (NPs) on La-doped SiO2 showed excellent selectivity toward ethanol for direct ethanol synthesis via CO hydrogenation. Over the catalyst with an optimal ratio of Ni/Co, the total alcohol selectivity reached 33.5%, of which ethanol occupied 47.0 wt %. The results demonstrated that the interaction between Co and Ni improved the ability to activate H2 and CO and adjusted the amount of the dissociatively and associatively adsorbed CO. Besides, the mutual dilution of nickel and cobalt in Ni–Co alloy NPs effectively reduced the isolated Co or Ni-clusters; thus, the formation of heavy hydrocarbons was suppressed. In the reaction process, Ni@Co–Co2C, a core–shell composite with a nickel core and Co–Co2C shell, was formed, which suppressed the loss of nickel species. Moreover, with the reaction going on, a small amount of poorly alloyed Co-clusters would be covered gradually by the formed coke, resulting in an increase in alcohol selectivity.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Lu Li,Xin Lyu,Saibo Liang,Zhanfang Liu
Hydrogen peroxide (H 2 O 2 ) is an important oxidant that exists widely in biological systems and the environment, and has been extensively used in medical, environmental, food, and industrial fields. Accurate, rapid, and sensitive detection of H 2 O 2 content is of great significance in the fields of biomedicine, environmental monitoring, food safety, and public safety. In this study, a probe was developed by utilizing Rhodamine 6G (Rh6G), a readily available commercial fluorescent dye, within hollow SiO 2 photonic crystals (HSPCs) to produce an amplified fluorescent signal. Furthermore, I - were incorporated into the system, which can be oxidized to I 2 in the presence of H 2 O 2 . The I 3 - produced can react with Rh6G to form a complex that quenches the fluorescence signal, enabling highly efficient detection of H 2 O 2 . The method does not require complex organic synthesis or modification of fluorescent groups. Additionally, the sensors exhibit good performance in terms of repeated use and can also potentially detect different concentrations of ethanol solutions.
研究领域:
生物医学
·
环境监测
·
食品安全
✓ 已验证
产品关联
DOI
高影响因子
ANALYST
·
2014
·Vol. 140
·期 2
·623-629
·
IF 3.906
Yonghai Song,Dongqin Hu,Fenfen Liu,Shouhui Chen,Li Wang
A simple strategy to fabricate a fluorescent SiO2@zeolitic imidazolate framework-8 (ZIF-8) core–shell nanosensor for Cu2+ detection was demonstrated in this work. The nanosensor was synthesized using carboxyl-functionalized SiO2 nanoparticles (SiO2 NPs) as a template to induce the growth of ZIF-8 on its surface. The porous SiO2@ZIF-8 exhibited extremely good adsorption properties and a large specific surface area to accumulate Cu2+, and the pyridyl nitrogen sites in imidazole played vital roles in the recognition of Cu2+. The fluorescent intensity decreased linearly with the increasing of Cu2+ concentration in the range of 10–500 nM and the detection limit was estimated to be 3.8 nM. The SiO2@ZIF-8 nanosensor could be further used to determine trace amounts of Cu2+ in real water samples, while some previous sensors had to be dispersed in organic solution for use, such as DMSO and MeCN. The core–shell nanostructures of SiO2@ZIF-8 made it possible for it to be dispersed directly in aqueous solution and prevented ZIF-8 from aggregation, which enhanced the sensing performance of the SiO2@ZIF-8 nanosensor.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 16
·13371-13376
·
IF 3.289
Yunshi Liu,Ping Yang,Jia Li,Katarzyna Matras-Postolek,Yunlong Yue,Baibiao Huang
SiO2@SnO2 core–shell nanofibers (NFs) were successfully prepared by single-spinneret electrospinning and subsequent calcination process. The precursor solutions were prepared from poly(vinylpyrrolidone), SnO2 precursors, and tetraethylorthosilicate (TEOS) with prehydrolysis. The prehydrolysis of TEOS plays an important role for the formation of core–shell structure. After calcining, the resulting fiber sample had an amorphous SiO2 core and a shell consisted of SnO2 particles. The fibers with various morphologies were obtained through adjusting the molar ratio of Sn and Si and the possible formation mechanism of core–shell NFs was proposed. Both Kirkendall effect and grain growth played important roles for the formation of core–shell structure. Furthermore, SiO2 was used as support material to fix the SnO2 particles and avoid the collapse of the SnO2 structure. The amount of SnO2 precursors directly determined the compactness of the shell, resulting in the different gas sensing properties. The SiO2@SnO2 core–shell NF network sensor responds to ethanol, ammonia, benzene, toluene, chloroform, and hexane gases, but it exhibited enhanced gas response to ethanol with a short response time. Those SnO2 particles formed on the exterior of the fibers provided lots of contact area with the target gas to reduce resistance. In addition, the connectivity between particles also had certain influence on the electrical conductivity of the sample. The results demonstrate that single-spinneret electrospinning can also be used to prepare core–shell fibers with various applications.
研究领域:
材料科学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 11
·2886
·
IF 5.076
Chao Bai,Shi He,Huai-Ming Hu,Hui Zeng,Feng Zou,Ji-Jiang Wang
A europium(III) hybrid material Eu(tta)3bpdc-SiO2@mTiO2(Htta = 2-thenoyltrifluoroacetone, H2bpdc = 2,2′-bipyridine-3,3′-dicarboxylic acid) was successfully designed and synthesized by the covalent grafting complex Eu(tta)3bpdc to SiO2@mTiO2core–shell nanosphere. The FT-IR, PXRD, XPS, TEM, HRTEM, SAED, TGA and PL were performed to characterize these materials. The results indicate that core–shell nanosphere structure and anatase crystallites of SiO2@mTiO2are retained well after grafting the europium complex. Hybrid material Eu(tta)3bpdc-SiO2@mTiO2displays uniform nanosphere structure, bright red color and long lifetime, which can serve as a multicolor emission material modulated by using Al3+ions via the cation exchange approach under a single-wavelength excitation. To the best of our knowledge, this work is the first multicolor emissive sensor for Al3+ions based on the lanthanide hybrid material.Keywords:lanthanide hybrid materials;SiO2@mTiO2core–shell nanosphere;bipyridine derivative;multicolor luminescence
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2022
·
IF 4.132
Gang Wang,Hua Tan,Chunjing Lu,Ao Sun
SiO2@PEGMA composites were synthesized by grafting poly(ethylene glycol) methacrylate (PEGMA) on SiO2 nanoparticles via radical polymerization. The chemical structures of the SiO2@PEGMA composites were analyzed by Fourier transform infrared, 1H NMR, and transmission electron microscopy methods. The mechanical and fresh properties, hydration products, heat of hydration, microtopography, and pore structures were studied. The shell formed by the grafted PEGMA gave the SiO2@PEGMA composite a steric hindrance effect, which enabled it to have excellent dispersion stability even in the cement pore solution. The SiO2@PEGMA composites could not only effectively facilitate hydration reaction and generate calcium silicate hydrate (C–S–H) through the seeding effect but also make the pore structure more compact by the filling effect. Compared with other control groups, SiO2@PEGMA composites could obviously enhance the compressive strength of cement samples, which was increased by 36.7% after curing for 28 days.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Wei Zhang,Shilu Zhang,Jing Wang,Meng Wang,Qiulai He,Jianyang Song,Hongyu Wang,Jinping Zhou
In this study, we prepared a novel hybrid functionalized chitosan-Al 2 O 3 @SiO 2 composite (FCAS) for removing hexavalent chromium [Cr(VI)] from aqueous system. Spectroscopic studies like Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy dispersive spectroscope (EDS) were characterized. The effects such as dosage of adsorbent, pH, contact time and initial Cr(VI) concentration were evaluated. It has been illustrated that a wide acidic condition in the pH range of 2–6 was conducive to Cr(VI) adsorption and only 10 min was required to reach about 80% adsorption. Also, the adsorption properties of prepared adsorbent such as kinetics, thermodynamics and isotherms were comprehensively studied. Additionally, the adsorption capacity barely declined even after five cycles. Studies found that FCAS with characteristics of high performance of adsorption rate and capacity and better reusability would be a potential adsorbent for wastewater treatment .
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2018
·
IF 4.9
Lin Li,Rong Chen,Xun Zhu,Qiang Liao,Dingding Ye,Biao Zhang,Xuefeng He,Long Jiao,Hao Feng,Wei Zhang
In this study, a novel ternary hybrid CdS/SiO 2 /TiO 2 film was proposed as the phonoanode for the photocatalytic fuel cell. The samples were characterized by X-ray diffraction, scanning electron microscopy and UV–vis absorption. The photoelectrochemical activity of the ternary hybrid electrode was characterized by the photocurrent-time transient response, linear sweep voltammetry and electrochemical impedance spectroscopy. It was shown that CdS/SiO 2 /TiO 2 yielded much higher photoelectrochemical activity than CdS/TiO 2 and bare TiO 2 did. The photoanode with CdS/SiO 2 /TiO 2 showed the highest photocurrent density of 4.6 mA cm −2 , exhibiting a 40% improvement over the conventional CdS/TiO 2 photoanode. The roles of SiO 2 and CdS in such a ternary configuration were elaborated. It was demonstrated that CdS could act as an excellent visible light captaturer to generate photo-induced charge carriers, and SiO 2 as a passivation layer to suppress the interfacial recombination of electrons and holes. Moreover, SiO 2 could allow for more CdS to be deposited at the photoanode owing to its high adsorption capacity . In addition, the effects of the SiO 2 content and the SILAR cycle time on the performance of the CdS/SiO 2 /TiO 2 photoanode were investigated. An optimal SiO 2 content of 10% could yield the best performance. Increasing the SILAR cycle time could improve the photoelectrochemical activity.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2020
·
IF 3.442
Tong Wu,Jingyao Li,Meiqi Chang,Yanhua Song,Qi Sun,Fangke Wang,Haifeng Zou,Zhan Shi
Dual functional Sm 3+ ion doped SiO 2 @TiO 2 composites were designed to investigate their luminescence properties and photocatalytic activities under ultraviolet and simulated solar light excitation, respectively. The TiO 2 :Sm 3+ nanoparticles , SiO 2 @TiO 2 :Sm 3+ nanospheres and SiO 2 @TiO 2 :Sm 3+ nanorods were successfully fabricated via the solvothermal method followed by the calcination at 700, 800 and 900 °C, respectively. The effects of morphology and calcination temperature on photocatalytic activities and luminescent properties were studied. The results demonstrated that the SiO 2 @TiO 2 :Sm 3+ nanorods calcined at 700 °C exhibited the highest luminescence intensities. This was attributed to possess the least specific surface area, which decreased the quenching center of surface defects , as well as without rutile phase. Moreover, SiO 2 @TiO 2 :Sm 3+ nanorods annealed at 800 °C were the optimum for improving the photodegradation efficiency of hydrolyzed polyacrylamide (HPAM) under simulated solar light irradiation. The degradation experiments results confirmed that the synergistic effect of the crystallinity/Ti–O–Si bond was the main reason for excellent photocatalytic activities. As a result, SiO 2 @TiO 2 :Sm 3+ nanorods meet our requirements for better photoluminescence intensities and photocatalytic activities.
研究领域:
材料科学
·
光学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Nano-Micro Letters
·
2022
·Vol. 14
·期 1
·1-20
·
IF 23.655
Song Limeng,Zhang Fan,Chen Yongqiang,Guan Li,Zhu Yanqiu,Chen Mao,Wang Hailong,Putra Budi Riza,Zhang Rui,Fan Bingbing
Traditional ceramic materials are generally brittle and not flexible with high production costs, which seriously hinders their practical applications. Multifunctional nanofiber ceramic aerogels are highly desirable for applications in extreme environments, however, the integration of multiple functions in their preparation is extremely challenging. To tackle these challenges, we fabricated a multifunctional SiC@SiO 2 nanofiber aerogel (SiC@SiO 2 NFA) with a three-dimensional (3D) porous cross-linked structure through a simple chemical vapor deposition method and subsequent heat-treatment process. The as-prepared SiC@SiO 2 NFA exhibits an ultralow density (~ 11 mg cm − 3 ), ultra-elastic, fatigue-resistant and refractory performance, high temperature thermal stability, thermal insulation properties, and significant strain-dependent piezoresistive sensing behavior. Furthermore, the SiC@SiO 2 NFA shows a superior electromagnetic wave absorption performance with a minimum refection loss ( RL min ) value of − 50.36 dB and a maximum effective absorption bandwidth ( EAB max ) of 8.6 GHz. The successful preparation of this multifunctional aerogel material provides a promising prospect for the design and fabrication of the cutting-edge ceramic materials.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 18
·11041-11048
·
IF 3.108
Yongqiang Li,Chao Zou,Jianzhong Shao,Xiangwu Zhang,Ya'nan Li
The preparation of superhydrophobic micro/nano fibers has been mainly focused on the use of electrospinning; however, practical applications are limited due to cost, scale and controllable research. Herein, we present a novel and simple centrifugal spinning technology that extrudes fibers from polymer solutions by using a high-speed rotary, perforated spinneret. By controlling the concentration of the spinning solutions and adjusting the spinning parameters, polystyrene (PS) fibers with different structures have been prepared. Since PS is a low surface energy material, the surface roughness can further increase the hydrophobicity of the fibers. We prepared hydrophobic SiO2 in different sizes, mixed them with PS dissolved in DMF, and SiO2/PS fibers were obtained by centrifugal spinning, where the maximum water contact angle of SiO2/PS fibers was 151° with superhydrophobicity. The typical surface of the silver ragwort leaf fibers with numerous grooves, and the lotus leaf with nano-protrusions, were successfully imitated on the centrifugally-spun SiO2/PS fiber surface. The as-prepared PS fibers were characterized by scanning electron microscopy and water contact angle/sliding angle measurements, and a processing–structure–performance relationship was established. Results demonstrate that the fiber morphology can be easily manipulated by controlling the spinning parameters, and centrifugal spinning is a promising approach for meeting the growing demand for the mass production of superhydrophobic micro/nano fibers.
研究领域:
材料科学
·
表面科学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Hong Du,Xiuyun Ma,Miao Jiang,Siyuan Zhao,Qi Fang,Xiumei Liu,Zongchao Conrad Zhang
Xylitol is a value-added health product from the hemicellulose component in biomass. In this work, highly efficient Cu–Ni/SiO2 catalysts are developed for the production of xylitol by means of xylose hydrogenation. The bimetallic catalysts exhibit higher activity compared to the corresponding monometallic nickel or copper catalyst and the currently used industrial Raney nickel catalyst. The bimetallic catalyst with a higher ratio of nickel to copper shows a better performance. The 5Cu15Ni/SiO2 catalyst exhibits a xylose conversion of 96% accompanied by higher than 99% selectivity to xylitol under the moderate conditions of 100 °C and 3MPa H2. The bimetallic catalysts show improved performances when they are activated at a low temperature. The apparent activation energies of xylose hydrogenation over the 5Cu15Ni/SiO2 and 20Ni/SiO2 catalysts are 16.6 and 25.2 kJ/mol, respectively. The formation of the Cu–Ni alloy leads to a lower activation energy and thus superior performance for xylose hydrogenation to xylitol.
研究领域:
生物化学
·
催化化学
✓ 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）