RSC Advances
·
2015
·Vol. 5
·期 93
·76182-76189
·
IF 3.84
Xiaotian Zhang,Guangqin Luo,Mingyuan Zhu,Lihua Kang,Feng Yu,Bin Dai
Designing a catalyst with excellent recyclability to improve oxidative desulfurization continues to challenge many researchers. In this study, a H4SiMo12O40@SiO2 catalyst with a core–shell structure was successfully prepared and applied to desulfurize a model oil. Various characterization methods demonstrated that the synthesized H4SiMo12O40@SiO2 catalyst presents a hollow spherical structure and that the active H4SiMo12O40 species is incorporated into the mesoporous SiO2 shell. Under optimal reaction conditions, the desulfurization rate of dibenzothiophene is nearly 100%, and the activation energy of the oxidation reaction of dibenzothiophene is 22.08 kJ mol−1. These results reveal the excellent catalytic activity of H4SiMo12O40@SiO2 for oxidative desulfurization. The catalyst can be recycled by up to 13 times without significant reductions in catalytic activity; such enhanced recyclability may be attributed to the core–shell structure of the synthesized catalyst.
研究领域:
催化化学
·
材料科学
·
环境化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2016
·
IF 4.839
Na Li,Fenglian Fu,Jianwei Lu,Zecong Ding,Bing Tang,Jiabin Pang
Chromium-contaminated water is regarded as one of the biggest threats to human health. In this study, a novel magnetic mesoporous MnFe 2 O 4 @SiO 2 −CTAB composite was prepared by a facile one-step modification method and applied to remove Cr(VI). X-ray diffraction, scanning electron microscopy, transmission electron microscopy , specific surface area, and vibrating sample magnetometer were used to characterize MnFe 2 O 4 @SiO 2 −CTAB composites. The morphology analysis showed that the composites displayed a core-shell structure. The outer shell was mesoporous silica with CTAB and the core was MnFe 2 O 4 nanoparticles , which ensured the easy separation by an external magnetic field. The performance of MnFe 2 O 4 @SiO 2 −CTAB composites in Cr(VI) removal was far better than that of bare MnFe 2 O 4 nanoparticles. There were two reasons for the effective removal of Cr(VI) by MnFe 2 O 4 @SiO 2 −CTAB composites: (1) mesoporous silica shell with abundant CTA + significantly enhanced the Cr(VI) adsorption capacity of the composites; (2) a portion of Cr(VI) was reduced to less toxic Cr(III) by MnFe 2 O 4 , followed by Cr(III) immobilized on MnFe 2 O 4 @SiO 2 −CTAB composites, which had been demonstrated by X-ray photoelectron spectroscopy results. The adsorption of Cr(VI) onto MnFe 2 O 4 @SiO 2 −CTAB followed the Freundlich isotherm model and pseudo-second-order model. Tests on the regeneration and reuse of the composites were performed. The removal efficiency of Cr(VI) still retained 92.4% in the sixth cycle. MnFe 2 O 4 @SiO 2 −CTAB composites exhibited a great potential for the removal of Cr(VI) from water.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
Advanced Materials Technologies
·
2021
·Vol. 7
·期 6
·2101169
·
IF 7.848
Wei Liu,Xue Wang,Zhiyang Zhao,Xin Zhou,Shiliang Huang,Longjin Huang,Zihan Wang,Jingru Li,Junjie Fu,Yu Liu,Sheng Cui,Xuan He
Flexible surface-enhanced Raman spectroscopy (SERS) substrates have received more and more attention for their non-invasive sample collection ability. However, majority of them have poor stability and reproducibility because noble metal is easily oxidized and led to lose SERS activity. Herein, SiO 2 -TiO 2 -Ag hybrids aerogel (STAHA) material is first applied as a flexible SERS substrate for explosives and dyes long-term sensitive detection. The sensitive non-invasive detection of 3-nitro-1, 2, 4-triazol-5-one (NTO) residues can be achieved with a limit of 1 × 10 −6 m by wiping sample collection method. Meanwhile, similar SERS sensitivity from long-term (50 days) kept substrates is observed compared with fresh-made substrates. This long-term sensitivity is contributed to electronic transfer compensation from TiO 2 aerogel. This proposed flexible STAHA enrich the type of SERS substrates, and their long-term sensitivity can provide a prospective application for trace analyses of explosives and other hazardous residues in criminal forensic, military, and security check.
研究领域:
材料科学
·
分析化学
·
环境安全
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2014
·
IF 3.209
Xuguang Liu,Lei Xu,Baoquan Zhang,Xiufeng Liu
Pd/SiO 2 catalytic hydro-cracking is applied to remove triethylamine template in an AFI type MnMgAlPO-5 molecular sieve . The triethylamine template reacts with spillover hydrogen inletting from the Pd/SiO 2 catalyst, and is hydro-cracked to small molecules at a mild temperature (613 K). This behavior is distinguish to the conventional template removal method of calcination above 823 K, and consistently proved by H 2 -TPR/MS, TG/MS, and N 2 -isotherms results. The catalytic hydro-cracking method does not damage the crystal structure of MnMgAlPO-5, indicated by XRD characterization. Its novelty is suggested as reserving the local symmetric structure of MnMgAlPO-5 ( i.e. , keeping framework Mn and Mg), consistently verified by EPR, UV–vis, and Raman spectra. This provides an alternative option for the template removal from molecular sieves.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
FERROELECTRICS
·
2020
·
IF 0.669
Qi Tang,Ting Yang,Song Wang,Hai-Lin Cong,Xin-Rui Yang,You-Qing Shen,Bing Yu
Magnetic composites have been widely used in the area of wastewater treatment, which own the properties of simple and quick adsorption and separation functions. This article presented a cost-effective and chemically modified adsorbent (Fe3O4@SiO2@Chitosan) based on a novel facile light-assisted technique for methyl orange (MO) removal. The characterization results of FT-IR, TEM, XRD and the hysteresis loop showed that Fe3O4@SiO2@Chitosan was successfully prepared. The adsorption properties of the magnetic Fe3O4@SiO2@Chitosan composite had been discussed in detail. Results show that the magnetic composite was able to remove more than 99.15% of dyes in water under optimized conditions. The Fe3O4@SiO2@Chitosan composite was stable and easily recovered, which demonstrated that the Fe3O4@SiO2@Chitosan can be successfully used as a reusable absorbent for effective removal of methyl orange from wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Mingliang Ma,Wenting Li,Zhouyu Tong,Yong Ma,Yuxin Bi,Zijian Liao,Jian Zhou,Guanglei Wu,Mingxia Li,Jiewei Yue,Xinyu Song,Xinyue Zhang
One-dimensional (1D) ZnFe 2 O 4 @SiO 2 (ZS) nanochains were prepared with Stöber method under external magnetic field. Then, 1D ZS nanochains were covered with a uniform polydopamine (PDA) shell, and the pyrolysis process was completed to obtain 1D ZnFe 2 O 4 @SiO 2 @C (ZSC) nanochains. Finally, 1D flower-like ZnFe 2 O 4 @SiO 2 @C@NiCo 2 O 4 (ZSCNC) nanochains were fabricated through a simple hydrothermal method. The carbon layer with strong dielectric loss enabled the 1D ZSC nanochains to achieve an ultra-wide effective absorption bandwidth (EAB) of 6.22 GHz. Compared with the above nanochains, the 1D ZSCNC nanochains showed more excellent microwave absorption (MA) properties because of the unique 1D flower-like architectures having large surfaces and multiple interfaces. The sample loaded with 30 wt% 1D flower-like ZSCNC nanochains showed strong MA performances with a minimum reflection loss (RL) value of −54.29 dB (11.14 GHz) and an EAB of 5.66 GHz (11.94–17.60 GHz) at the thickness of 2.39 mm. The 1D flower-like ZSCNC nanochains with strong absorption, broad absorption bandwidth (almost the entire Ku band) and thin layer has a good application prospect for the absorption of electromagnetic waves in Ku band.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2019
·Vol. 89
·期 3
·623-633
·
IF 1.986
An Zhimin,Ye Changshou,Zhang Rubing,Qu Qiang
Abstract A C/SiO 2 /SiC ternary aerogel was prepared from a formaldehyde–catechol/silicon source via the sol−gel method, supercritical drying, and high-temperature carbothermal reduction. The effects of different carbon/silicon molar ratios on the microstructure, chemical composition, and mechanical and shielding properties of the C/SiO 2 /SiC aerogels were investigated. The fabricated aerogels exhibited low density of 0.118–0.271 g/cm 3 , low thermal conductivity of 0.044 to 0.089 W/(m∙K) and a high specific surface area of 774 m 2 /g. The aerogel exhibited electromagnetic interference shielding effectiveness (SE) properties; the maximum SE value was 24 dB over 12.4–18.0 GHz with an absorption-dominant shielding characteristic. To improve the mechanical properties of the ternary aerogel, novel SiC w -C/SiO 2 /SiC aerogel composites were prepared by adding different contents of SiC whiskers into precursor solutions. The mechanism affecting thermal and mechanical properties of aerogel composites was investigated. This composite having high strength and low thermal conductivity had potential applications in space shuttles and reusable carrier thermal protection materials.
The fabricated C/SiO 2 /SiC ternary aerogels exhibited low density of 0.118–0.271 g/cm 3 and low thermal conductivity of 0.044−0.089 W/(m∙K). The aerogel exhibited electromagnetic interference shielding effectiveness (SE) properties; the maximum SE value was 24 dB over 12.4–18.0 GHz with an absorption-dominant shielding characteristic.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2011
·
IF 1.795
Mengjia Yuan,Shengtian Wang,Xiaohong Wang,Lingling Zhao,Tianhong Hao
A new macroporous ZnO/MoO 3 /SiO 2 hybrid was synthesized by a method involving sol–gel technology and biomimetic synthesis. It was characterized by Elemental analysis, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectrum (XPS) and scanning electron microscopy (SEM). Chemical degradation of 0.3 g/L Safranin T (ST) by air oxidation over macroporous ZnO/MoO 3 /SiO 2 hybrid was studied. It was found that the decolorization efficiency and the chemical oxygen demand (COD) removal of ST reached above 95.3% and 93.2%, respectively, within 25 min at room temperature and atmospheric pressure. And the organic pollutant was mineralized to simple inorganic species such as HCO 3 − , Cl − and NO 3 − , while the total organic carbon (TOC) decreased 95.4%. The structure and morphology of the catalyst were still stable after six cycling runs and the leaching test showed negligible leaching effect.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Na Chen,Huan Zhang,Xu-Dong Luo,Chuan-Yu Sun
In this paper, the SiO 2 -decorated graphite felts are obtained by silicic acid etching graphite felts in hot air, and their performance as the electrodes of iron-chromium redox flow battery (ICRFB) is investigated. The surface morphology, microstructure and surface chemical composition of SiO 2 -decorated graphite felts are characterized in detail through scanning electron microscopy, specific surface area analysis, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy. The electrocatalytic activity of SiO 2 -decorated graphite felts and the performance in ICRFBs are studied by electrochemical impedance spectroscopy , cyclic voltammetry , and single-cell charge-discharge cycling tests. Results indicate that the SiO 2 introduced by the decomposition of silicic acid can increase the effective specific surface area of the graphite felts, and concurrently facilitate the oxidation of the SiO 2 -decorated graphite felts in hot air. The number of oxygen functional groups and the defect sites on the surface of the SiO 2 -decorated graphite felts increase to a great degree that especially have a considerable influence on the negative reaction activity of the ICRFB. An ICRFB assembled with graphite felts etched by 50 wt% silicic acid as the electrodes has a voltage efficiency and energy efficiency of 86.27% and 79.66% at a current density of 120 mA/cm 2 , respectively. The decay rate of capacity is only 0.46% per cycle. The cost-effective and convenient method demonstrated in this paper can coordinate the control of oxygen functional groups, surface area and electrical conductivity of graphite felts, which may provide an example for improving the electrode materials for the commercial application of ICRFBs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Energy Technology
·
2016
·Vol. 4
·期 8
·943-949
·
IF 2.557
Dong Pi,Wen Zhi Li,Qi Zhao Lin,Qi Fu Huang,Hui Qing Hu,Chun Yu Shao
A series of Pd-based core–shell catalysts (Pd@SiO 2 , Pd@CeO 2 , and Pd@ZrO 2 ) supported on Si-modified Al 2 O 3 were prepared for the catalytic combustion of lean methane. Pd@SiO 2 exhibited slightly lower catalytic activity than Pd@CeO 2 and higher catalytic activity than Pd@ZrO 2 in dry conditions; however, Pd@SiO 2 had the highest catalytic activity among the three catalysts in the presence of high concentrations of water vapor. Furthermore, the Pd@SiO 2 catalyst showed good thermal stability and resistivity to water poisoning. CO chemisorption and TEM results demonstrated that the core–shell structure could help in the stabilization of the active phase compared to the uncoated Pd/Si-Al 2 O 3 catalyst. XRD and X-ray photoelectron spectroscopy results indicated that a balanced mixed phase of PdO x /Pd 0 is the main active phase of these Pd-based catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2016
·Vol. 146
·期 8
·1408-1414
·
IF 2.294
Kang Yumei,Bu Xiaosong,Wang Guangyu,Wang Xiaoqing,Li Qianwen,Feng Yisi
Abstract A series of bimetallic Cu samples (Cu–Pt/SiO 2 , Cu–Pd/SiO 2 , Cu–Ag/SiO 2 , Cu–Ni/SiO 2 ) were prepared by wetness impregnation method, then investigated for hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO). We furthered the study and found that Cu–Pt/SiO 2 got the smallest particle size and greatest dispersion. Besides, it was found that Pt promoted reduction of Cu 2+ . Compared with other Cu–Pt molar ratio, Cu–Pt/SiO 2 (1:0.2) was the preferable catalyst for hydrogenolysis of glycerol to 1,2-PDO. It is worth noting that Cu–Pt/SiO 2 presented the highest activity with a 96 % selectivity to 1,2-PDO and a nearly 100 % conversion of glycerol at 473 K, 40 bar initial H 2 pressure, 12 h, which is much higher activity than monometallic Cu/SiO 2 , Pt/SiO 2 and other bimetallic Cu samples. Meanwhile, the used Cu–Pt/SiO 2 catalyst still preformed high activity. Furthermore, it was found that the presence of Pt decreased the aggregation of particles during the hydrogenolysis of glycerol. Graphical Abstract
研究领域:
催化化学
·
材料科学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2013
·
IF 2.915
Jie Cui,Ting He,Xu Zhang
Platinum ion doped magnetic TiO 2 (Fe 3 O 4 @SiO 2 @Pt ion –TiO 2 ) hybrid microspheres with uniform magnetic cores were synthesized and characterized in this work. The results indicate that the photoactivity of Fe 3 O 4 @SiO 2 @Pt ion –TiO 2 is much higher than Fe 3 O 4 @SiO 2 @TiO 2 for the decolorization of acid orange 20 under UV–visible light irradiation. The trend for the final degradation ratio with Fe 3 O 4 @SiO 2 @Pt ion –TiO 2 is quite small, even after seven repetitive experiments. These data indicate that the magnetic microspheres possess the potential to be effective and stable catalysts. The results demonstrate that the Pt ion doped magnetic catalyst meets the needs for both immobilization and high photoactivity.
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
危险品化学品经营许可证（带存储）