APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Xi-Lin Wu,Yanpeng Shi,Shuxian Zhong,Hongjun Lin,Jian-Rong Chen
Herein, we have developed a facile and low-cost method for the synthesis of novel graphene based nanosorbents. Firstly, well-defined Fe 3 O 4 nanoparticles were decorated onto graphene sheets, and then a layer of mesoporous SiO 2 were deposited on the surface of the Fe 3 O 4 -graphene composites. The obtained Fe 3 O 4 -graphene@mesoporous SiO 2 nanocomposites (denoted as MG@m-SiO 2 ) were characterized by scanning electron microscopic (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transformed infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The adsorptive property was investigated by using MG@m-SiO 2 as sorbents and Methylene Blue (MB), a common dye, as model of the organic pollutants. Adsorption kinetics, isotherms, thermodynamics as well as effects of pH and adsorbent dose on the adsorption were studied. The adsorption isotherms and kinetics are better described by Langmuir isotherm model and pseudo-second-order kinetic model, respectively. Thermodynamic studies suggest that the adsorption of MB onto the MG@m-SiO 2 is endothermic and spontaneous process. The results imply that the MG@m-SiO 2 can be served as a cost-effective adsorbent for the removal of organic pollutants from aqueous solutions.
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
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Xueqian Wu,Jin Zhao,Jiangyan Tao,Jiawen Chi,Xin Min,Songjian Zhao
As a major greenhouse gas, the rational conversion and utilization of CO 2 can help reduce carbon emissions and mitigate the greenhouse effect. In this study, mesoporous SiO 2 as a carrier, with CuO and NiO employed to construct a binary metal composite silica-based catalyst, coupled with dielectric barrier discharge (DBD) plasma, for the conversion of CO 2 . Physicochemical analysis confirmed the successful introduction of CuO into the mesoporous SiO 2 . NiO and CuO bimetals were dispersed on SiO 2 surfaces with large specific surface areas, ensuring an optimal distribution of metal oxide. Gas chromatography was utilized to investigate the performance of DBD-coupled x%CuO-3 %NiO/Si for CO 2 conversion. The results indicated that the CuO-NiO binary composite silica catalysts significantly improved CO 2 conversion, CO yield, and energy efficiency compared to the monometallic 3 %NiO/Si materials. Further microstructural analysis of the 9 %CuO-3 %NiO/Si catalyst revealed near-elliptic particles with dimensions of 200 by 500 nm and a large number of irregular fine particles attached to the surface. When the CuO loading reached an optimal level and the input power was set at 30 W, the energy efficiency of the 9 %CuO-3 %NiO/Si catalyst increased by 119.6 %. The CuO-NiO binary composite Si-based catalyst developed in this study boasts simple operation and environmental friendliness, making it highly significant for CO 2 treatment.
研究领域:
环境科学
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材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2013
·Vol. 18
·期 11
·14258-14267
·
IF 2.428
Huan Liu,Chao Lin,Zhen Ma,Hongbo Yu,Shenghu Zhou
Fe3O4spheres with an average size of 273 nm were prepared in the presence of CTAB by a solvothermal method. The spheres were modified by a thin layer of SiO2, and then coated by mesoporous SiO2(m-SiO2) films, by using TEOS as a precursor and CTAB as a soft template. The resulting m-SiO2/Fe3O4spheres, with an average particle size of 320 nm, a high surface area (656 m2/g), and ordered nanopores (average pore size 2.5 nm), were loaded with gold nanoparticles (average size 3.3 nm). The presence of m-SiO2coating could stabilize gold nanoparticles against sintering at 500 °C. The material showed better performance than a conventional Au/SiO2catalyst in catalytic reduction ofp-nitrophenol with NaBH4. It can be separated from the reaction mixture by a magnet and be recycled without obvious loss of catalytic activity. Relevant characterization by XRD, TEM, N2adsorption-desorption, and magnetic measurements were conducted.
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Xin Ning,Yiyuan Lu,Heyun Fu,Haiqin Wan,Zhaoyi Xu,Shourong Zheng
Supported Ni catalysts on three mesoporous SiO2 supports (i.e., SBA-15, MCM-41, and HMS) were prepared using a solid-state reaction between Ni(NO3)2 and organic template-occluded mesoporous SiO2. For comparison, supported Ni catalysts on mesoporous SiO2 synthesized by the conventional impregnation method were also included. The catalysts were characterized by scanning electron microscopy, X-ray diffraction, UV–vis diffuse reflectance spectroscopy, N2 adsorption, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, transmission electron microscopy, and transmission electron microscopy–energy-dispersive X-ray. The catalytic properties of the catalysts were evaluated using gas-phase catalytic hydrodechlorination of 1,2-dichloroethane. The results showed that upon grinding Ni(NO3)2 with template-occluded mesoporous SiO2, strong coordination between Ni2+ and dodecylamine was identified in the Ni(NO3)2–HMS system. Additionally, the results of H2 temperature-programmed reduction revealed that NiO in calcined NiO/HMS was reduced at higher temperature than those in calcined NiO/SBA-15 and NiO/MCM-41, reflecting the presence of a strong interaction between NiO and mesoporous SiO2 in NiO/HMS. Consistently, the average particle sizes of metallic Ni were found to be 2.7, 3.4, and 9.6 nm in H2-reduced Ni/HMS, Ni/SBA-15, and Ni/MCM-41, respectively, indicative of a much higher Ni dispersion in Ni/HMS. For the catalytic hydrodechlorination of 1,2-dichloroethane, Ni/MCM-41 synthesized by the solid-state reaction method exhibited a catalytic activity similar to that prepared by the impregnation method, while higher catalytic activities were observed on Ni/HMS and Ni/SBA-15 than on their counterparts prepared by the impregnation method. Furthermore, a higher conversion was identified on Ni/HMS than on Ni/SBA-15 and Ni/MCM-41, highlighting the importance of template type for the preparation of highly dispersed metal catalysts on mesoporous SiO2.
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2019
·
IF 4.175
Wei Wang,Jiaojiao Fang,Hu Chen
Mesoporous materials offer attractive routes for designing photocatalysts with nano-confined structures, high activities, and recyclability. Here we take the core-shell and mesoporous SiO 2 nanoparticles as the template for the in situ synthesis of nano-confined g-C 3 N 4 with controllable structures and quantum size effects by varying the precursor species and concentrations. Results indicate that decrease the cyanamide, the precursor, concentration will improve the specific surface area, adsorption ability, and quantum size effect of the final photocatalysts. Cyanamide aqueous solution with a weight ratio of 50.0 wt% results in the most active photocatalyst containing 31.17 wt% of the confined g-C 3 N 4 with a tetracycline degradation rate of 6.63 times higher than that of the cyanamide-derived bulk g-C 3 N 4 (C) under the xenon lamp irradiation. Replacing the cyanamide with urea can further improve the photocatalytic activity even the more active SiCN(U10) contains only 12.47 wt% of the confined g-C 3 N 4 . The improved photocatalytic activity is resulted from the synergistic effects of the high adsorption ability, low aggregation, enhanced quantum size effect, and more exposed active sites. The present study gives new sight on improving the aqueous phase recyclability of the few-layered and high-reactive g–C 3 N 4 –based photocatalysts, and may promote its industrial application process.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2018
·Vol. 125
·期 1
·199-211
·
IF 1.515
Hao Fang,Yang Yongzhe,Xiong Wei,Liu Pingle,You Kuiyi,Luo He’an
Mesoporous SiO 2 –Al 2 O 3 supported Cr 2 O 3 catalysts were prepared by the sol–gel and impregnation methods. These catalysts were characterized and applied in cyclohexane nitrosation reaction. The effects of the preparation conditions and the catalyst deactivation were studied. The results show that 20% Cr 2 O 3 /SiO 2 –Al 2 O 3 catalyst calcined at 400 °C exhibits not only the larger surface area, smaller particle size, but also the larger amount of Cr 2+ and Brønsted acid sites. These catalysts show good catalytic performances in the cyclohexane nitrosation to ε-caprolactam and could be recycled for several times in this reaction system for the first time. The catalyst of Cr 2 O 3 /SiO 2 –Al 2 O 3 calcined at 400 °C gives 10.8% conversion with 79.9% selectivity to ε-caprolactam.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Xiao Miao,Guina Ren,Xiaolong Zhang,Jianhua Jiao,Changqing Zhu,Qianqian Du,Bo Ge,Cancan Liu
Solar steam generation devices assembled based on interfacial heating technology show the ability to produce clean water, while it faces challenges in the sewage environments. The superhydrophobic fabric was used to selectively adsorb surface oily pollutants based on its non-wettability. Soluble pollutants remaining in water after evaporator treatment can be further removed through photodegradation . Herein, the device composed of superhydrophobic C 3 N 4 /Bi 2 MoO 6 heterojunction , water supply layer and CuO photothermal layer was assembled to remove oily and water-soluble pollutants and produce clean water. The contact angle of water on the superhydrophobic C 3 N 4 /Bi 2 MoO 6 surface reaches 154° and shows the selective adsorption of cyclohexane . The prepared bulk catalyst C 3 N 4 /Bi 2 MoO 6 not only indicate the stability of reuse, but also maintained the degradation efficiency of 98.7% under outdoor light conditions. Through the active species capture experiments, •O 2 − was verified as the main active material in the photodegradation process. The formation of Type II heterojunctions between C 3 N 4 and Bi 2 MoO 6 facilitated the separation of e − /h + at the C 3 N 4 /Bi 2 MoO 6 interface.
研究领域:
环境科学
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 12
·13161-13170
·
IF 1.798
Qin Tianxiu,Zhang Shuxia,Chen Pei,Zhao Fengqi,Gao Hongxu,Chen Xinbing,An Zhongwei
TiO 2 nanocrystals are inserted in the pores of monodispersed mesoporous SiO 2 nanospheres with 20–35 nm diameter by a facile two-step method involving vacuum-rotary evaporation and subsequent calcination. Characterization by XRD, TEM, EDX, FT-IR and N 2 sorption techniques suggests that, the pores of the mesoporous SiO 2 nanosphere can effectively stabilize the anatase phase of TiO 2 nanocrystals with size about 6 nm even at high temperature of 750 °C. The photocatalytic activities of the samples with different TiO 2 loading amount were evaluated by the degradation of Rhodamine B dye in aqueous solution under UV-light irradiation. It is found that photocatalytic efficiencies of these materials are much better than commercial P25. Where the sample with TiO 2 loading of 43 % exhibits the highest photocatalytic efficiencies with complete degradation of Rhodamine B within 32 min, which is attributed to the balance between high surface area and suitable TiO 2 loading amount.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
PROCESS BIOCHEMISTRY
·
2019
·
IF 2.883
Bin Zou,Pengyun Wang,Zhenjiang Liu,Jiaojiao Xia,baihan Chen,Zhiyuan Tan
2,5-Furandicarboxylic acid (FDCA) has the potential to replace terephthalic acid (TPA) as a building block in the preparation of bio-based and degradable polyester materials. However, the lack of efficient and stable catalysts limits the commercial viability of FDCA production. In this work, metalloporphyrins were immobilized on mesoporous SiO 2 and used as a novel oxidase to convert 5-hydroxymethylfurfural (HMF) to FDCA. As the catalytic active center of P450 monooxygenases and horseradish peroxidase, supported palladium, manganese, ferri, and cobalt porphyrins via ionic-liquid-functionalized SiO 2 (PdPOP-SiO 2 , MgPOP-SiO 2 , FePOP-SiO 2 and CoPOP-SiO 2 ) were able to simulate oxidase alone under mild conditions. 100% HMF (0.02 M) conversion and 94.94% FDCA yield were achieved using PdPOP-SiO 2 as a biomimetic oxidase after a 12 h reaction at 373 K in water at atmospheric pressure. This type of mimetic oxidase is stable, inexpensive, and readily available, and the method developed in this work can potentially be used to oxidize HMF to FDCA in an industrial setting.
研究领域:
化学工程
·
生物催化
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Interfaces
·
2022
·Vol. 9
·期 19
·2200571
·
IF 6.389
Tingyu Yang,Yihua Zhu,Xiaoling Yang,Jianhua Shen
Perovskite quantum dots (PQDs) have attracted widespread attention in optoelectronic fields due to their excellent optical properties. However, their instability issue hampers their further development and practical application. Herein, CsPbBr 3 PQDs embedded in mesoporous SiO 2 microspheres (CsPbBr 3 PQDs/MSs) are prepared by the high-temperature solid-phase melting method due to the confinement effect. The prepared CsPbBr 3 PQDs/MSs are treated by saturated Na 2 SO 4 to form PbSO 4 precipitation to fulfill the mesoporous gap. And such treatment endows the QDs with excellent water, light irradiation, and heating stability. The prepared products can maintain over 80% of the original fluorescence intensity even when it is immersed in water for 2 weeks. The CsPbBr 3 PQDs/MSs are utilized in the white light-emitting diode device with Commission Internationale de L'Eclairage color coordinates of (0.3407, 0.3357) at 20 mA, and exhibit excellent photo stability at high power.
研究领域:
材料科学
·
光学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Asian Journal of Organic Chemistry
·
2022
·Vol. 11
·期 8
·e202200234
·
IF 3.116
Yifei Ye,Yanglin Chen,Junzhe Huang,Jianmin Sun
Graphical A series of functionalized ionic liquids (ILs) immobilized on B-doped mesoporous SiO 2 catalysts were fabricated for effectively converting CO 2 into cyclic carbonates under metal-absent and cocatalyst-free conditions A series of functionalized ionic liquids (ILs) immobilized on B-doped mesoporous SiO 2 catalysts were fabricated for effectively converting CO 2 into cyclic carbonates under metal-absent and cocatalyst-free conditions. Functionalized imidazolium ILs were in-situ synthesized by Debus-Rdziszewski imidazole reaction. Among the prepared catalysts, 5B−SiO 2 −NH 2 −3−I catalyst owing to the synergistic effects of nucleophile, Lewis acid-base and hydroxyl hydrogen bond donors in the catalyst, presented the better catalytic activity for propylene epoxide to the product of propylene carbonate with 99% yield and selectivity at 110 °C and 2 MPa CO 2 . The catalyst also displayed moderate yield for various mono-substituent epoxides. Besides, the gradual decline in the product yield during consecutive runs could be easily refreshed by aqueous acidic solution washing.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2015
·
IF 4.321
Xinhong Qi,Xiangcun Li,Gaohong He,Yangzhi Zhu,Yurong Diao,Huilan Lu
Noble metal nanocrystals (Au, Pt or AuPt) with controlled compositions and nanostructures were embedded into hollow silica submicrospheres with highly ordered radial mesopores through a one-step sol–gel process. 2,4-Dihydroxybenzoic acid–formaldehyde (RF-COOH) resin submicrospheres were utilized simultaneously as a hard template to create hollow interiors inside the silica submicrospheres and as carriers to transport pregrown metal nanocrystals, including Au nanoparticle (NP), Pt NP, and AuPt nanoalloy, into the submicrospheres. Calcination removes the resin submicrospheres and causes metal nanocrystals embedded into the RF-COOH submicrospheres break into multiple smaller nanoparticles (2–6 nm) that are randomly dispersed in the hollow space of SiO 2 submicrospheres M@SiO 2 (M = Au, Pt or AuPt). The AuPt@SiO 2 submicrospheres showed good catalytic performance for epoxidation of styrene with the conversion and selectivity of 74% and 85%, respectively. The approach reported in this study could potentially be used to simplify the fabrication process of noble metal nanoalloys, which usually entails multiple steps and a previously synthesized hard metal template, and thus guide the design and creation of high-performance catalysts.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）