RSC Advances
·
2018
·Vol. 8
·期 59
·34069-34077
·
IF 2.936
Minhua Zhang,Xuechao Tan,Tong Zhang,Zheng Han,Haoxi Jiang
A deactivation study on the ethanol/acetaldehyde conversion to 1,3-butadiene over a ZnO promoted ZrO2–SiO2 catalyst prepared by a sol–gel method was performed. The samples were characterized by N2 adsorption–desorption isotherms, scanning electron microscopy (SEM), NH3 temperature programmed desorption (NH3-TPD), X-ray powder diffraction characterization (XRD), thermogravimetric analyses (TGA), Fourier transform infrared resonance (FT-IR), 13C magic-angle spinning nuclear magnetic resonance (13C NMR) and X-ray photoelectron spectroscopy (XPS). The pore structure characteristics and surface acidity of Zn0.5–Zr–Si catalysts were largely decreased with time-on-stream and no crystal structure was formed in the used catalyst, indicating that the deactivation was caused by carbon deposition. Two main types of carbon deposition were formed, namely low-temperature carbon deposition with the oxidation temperature of around 400 °C and high-temperature carbon deposition with the oxidation temperature of 526 °C. The carbon species were mainly composed of graphitized carbon, amorphous carbon, carbon in C–O bonds and carbonyls. The deactivated catalyst could be regenerated by a simple oxidation process in air. Adding a certain amount of water into the feed had a positive effect on reducing the carbon deposition.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2018
·
IF 2.955
Guomin Wu,Di Liu,Jian Chen,Guifeng Liu,Zhenwu Kong
Nanocomposite films with super hydrophobic surface were prepared by building rough micro/nano structure on the surface of siloxane-modified two-component waterborne polyurethane (2K-WPU) with hydrophobic nano SiO 2 . Firstly, nano SiO 2 prepared by StÖber method with tetraethoxysilane (TEOS) as precursor was modified with trimethylethoxysilane (TMES), in order to cover a layer of hydrophobic methyl groups on the surface of nano SiO 2 . Then, a series of nanocomposite films with different water contact angles were obtained by adding different contents of TMES modified SiO 2 into the siloxane-modified 2K-WPU. The effects of the content of nano SiO 2 on the morphology and hydrophobicity of film surface were investigated. The results showed that the surface structures of the nanocomposite films became rougher and the water contact angle of nanocomposite films was increased obviously with the increase of the content of hydrophobic nano SiO 2 . Super hydrophobic nanocomposite film with water contact angle over 150° was successfully fabricated by using polysiloxane as low surface energy material and hydrophobic nano SiO 2 as micro/nano rough structure builder on the polymer surface. Moreover, incorporating nano SiO 2 into the 2K-WPU matrix could increase the glass transition temperature and thermal stability of the nanocomposite films.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Nanomaterials
·
2015
·
IF 1.644
Song Yang,Tian Zeng,Yaling Li,Jun Liu,Qian Chen,Ji Zhou,Yong Ye,Bin Tang
The fast detection and removal of organic dyes from contaminated water has become an urgent environmental issue due to their high toxicity, chemical stability, and low biodegradability. In this paper, we have developed graphene oxide decorated Fe3O4@SiO2 (Fe3O4@SiO2-GO) as a novel adsorbent aiming at the rapid adsorption and trace analysis of organic dyes followed by surface enhanced Raman scattering (SERS). The structure and morphology of the nanocomposites were characterized by transmission electron microscopy (TEM), Fourier infrared spectrometry (FT-IR), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The obtained nanocomposites were used to adsorb methylene blue (MB) in aqueous solution based on π-π stacking interaction and electrostatic attraction between MB and GO, and the adsorption behaviors of MB were investigated. Moreover, the obtained nanocomposites with adsorbed dyes were separated from the solution and loaded with silver nanoparticles for SERS detection. These nanocomposites showed superior SERS sensitivity and the lowest detectable concentration was 1.0 × 10−7 M.
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
CATALYSIS LETTERS
·
2022
·Vol. 153
·期 8
·2504-2516
·
IF 2.936
Chen Jiaxuan,Hu Shen,Chen Zhuo,Sun Xincheng,Chen Minhao,Chen Tianjiao,Ye Guanghua,Zhou Xinggui
The effects of molecular size on SiO 2 deposition regulated surface barriers and zeolite catalysis are probed, taking n -pentane isomerization and benzene alkylation with ethylene as model reactions. Chemical liquid deposition of SiO 2 on the parent ZSM-5 sample only modifies its external surface slightly and passivates a small proportion of Brønsted acid sites. The apparent diffusivities increase significantly at 363–393K after SiO 2 deposition, indicating SiO 2 on ZSM-5 crystals reduces surface barriers at low temperatures. The conversion for n -pentane isomerization increases by up to 26% after SiO 2 deposition, while the conversion for benzene alkylation decreases by up to 19%. Obviously, the positive effect of SiO 2 deposition can be balanced out by the pore confinement effect at high temperatures, which is stronger for a larger molecule. This work provides a unique understanding of molecular size effects on surface barriers, which should serve to guide the design of zeolite catalysts. Graphical Abstract
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
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Shuibo Wang,Chunzheng Wu,Hongbo Yu,Yuting Chu,Shiwei Wang,Tong Li,Hongfeng Yin
Tailoring the interface between active metals and promoters to improve catalytic performance is a challenging issue for bicomponent catalysts. Herein, we developed a series of silica supported Pt-CoO x hybrid nanocatalysts though in situ oxidation of supported bimetallic PtCo nanoparticles (NPs) with different Pt/Co ratios. Focusing on the hydrogenation of acetophenone to 1-phenylethanol as the model reaction, the obtained Pt-CoO x /SiO 2 catalysts showed superior activity and selectivity compared to Pt/SiO 2 , and the sample with a Co/Pt molar ratio of 1/3 performed the best. Our research showed that the CoO x on Pt not only changed its electronic and geometric properties, but also promoted the adsorption of reactants and the dissociation of H 2 . A further increase of the Co/Pt ratio to 1/1, however, reduced the activity due to blockage of the Pt surface.
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
ACS Applied Energy Materials
·
2023
·
IF 6.4
Hao Li,Shenyue Gao,Hang Ding,Yuetong Tao,Shenghua Ma,Gang Wang,Beibei Wang
Interfacial solar steam generation is considered the next-generation desalination and sewage treatment technology. However, realizing solar evaporators with broad-spectrum absorption, efficient thermal conversion, and high stability remains a challenge. The high light-trapping surface structure and fast water transport channels of the evaporator improve the evaporation efficiency, and solar evaporators have great potential in the field of solar steam generation. Herein, the mixture of transition-metal carbide (Ti3C2Tx) and core–shell Ag–SiO2 nanoparticles (Ag@SiO2 NPs) is fabricated as a three-dimensional (3D) vertical porous Ti3C2Tx/Ag@SiO2 gel evaporator via ice templating technology. The synergistic interaction between dual Ti3C2Tx–Ag plasma materials confined in a cross-linked microcapillary structure realizes 97.6% wide absorption in the wavelength range of 250–2500 nm. The SiO2 coating on the surface of Ag NPs can inhibit the oxidation of Ag NPs and conduct heat collection management. The 3D vertically cross-linked porous structure promotes efficient water transport and improves the mechanical strength of the evaporator. The Ti3C2Tx/Ag@SiO2 gel evaporator exhibits a high evaporation rate of 1.42 kg m–2 h–1 and a photothermal conversion efficiency of 98% under 1 sun illumination. The Ti3C2Tx/Ag@SiO2 gel evaporator shows great application prospects in seawater desalination and sewage purification.
研究领域:
材料科学
·
能源技术
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 24
·7970
·
IF 4.6
Gang Deng,Lu Yao,Mingzhao Chen,Yuanyuan Yang,Song Lu,Guohua Wu
With the improvement in people’s living standards, the development and application of smart textiles are receiving increasing attention. In this study, a carbon nanosurface was successfully coated with a SiO2layer to form C@SiO2nanomaterials, which improved the dispersion of carbon nanomaterials in an aqueous solution and enhanced the absorption of light by the carbon nanoparticles. C@SiO2nanoparticles were coupled on the surface of silk fabric with the silane coupling agent KH570 to form C@SiO2nanosilk fabric. The silk fabric that was subjected to such surface modification was endowed with a special photothermal function. The results obtained with scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and infrared spectroscopy (FTIR) showed that C@SiO2nanoparticles were successfully modified on the surface of the silk fabric. In addition, under the irradiation of near-infrared light with a power of 20 W and a wavelength of 808 nm, the C@SiO2nanosilk fabric experienced rapid warming from 23 °C to 60 °C within 30 s. After subjecting the functional fabric to hundreds of photothermal experiments and multiple washes, the photothermal efficiency remained largely unchanged and proved to be durable and stable. In addition, the thermogravimetric (TG) analysis results showed that the C@SiO2nanoparticles contributed to the thermal stability of the silk fabric. The UV transmittance results indicated that C@SiO2nanofabric is UV-resistant. The silk modification method developed in this study is low-cost, efficient, and environmentally friendly. It has some prospects for future applications in the textile industry.
研究领域:
材料科学
·
纺织工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·
IF 3.9
Renhan Li,Gongxun Bai,Hongbin Zhang,Enhai Song,Jiasong Zhang,Denghao Li,Junjie Zhang,Shiqing Xu
As an environment-friendly powder with good coloring performance, rare earth sulfide is one kind of the important choices to replace cadmium and lead colorants. In particular, γ-Ce 2 S 3 belongs to rare earth sesquisulfide, which has a bright red color. However, the uncoated γ-Ce 2 S 3 is easy to decompose and release H 2 S in a humid or acidic environment, and its air thermal stability is limited to 350°C. In this work, γ-Ce 2 S 3 powders coated with zinc oxide were prepared by heterogeneous precipitation method, and a dense protective layer was formed by ZnO to improve chemical and thermal stability. Moreover, silicon dioxide was deposited on the surface of the zinc oxide coating using the microemulsion process to strengthen the powder's acid resistance. The double shells structure greatly promoted thermal stability and acid resistance of γ-Ce 2 S 3 powders. The results showed that rare earth sulfide powders with double shells have good stability for coloring applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Wenyue Jiao,Zunyi Liu,Tianwen Huang,Lei Tan,Yan Hao,Yicheng Wang,Tingrui Lin,Hui Yang,Huazheng Sai
A superhydrophilic and underwater superoleophobic cellulose graft copolymer/SiO 2 coated metal mesh (CASi/M) was fabricated through a facile and cost-effective process. As-prepared CASi/M could separate different oil-water mixture with a separation efficiency higher than 99.4 % and a flux up to 26940 L·m −2 ·h −1 only driven by gravity. The reusability experiment showed that the separation efficiency still exceeded 99.2 % after 25 cycles, which displayed superior reusability. Furthermore, CASi/M displayed superior stability in corrosive liquids such as acidic, alkaline, and salty environments. This work provides new sights in the development of durable and low-cost functional materials for rapid and efficient oil/water separation.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 24
·21089-21095
·
IF 2.195
Sun Fan,Chen Guixiong,Zhou Xiongtu,Wu Chaoxing,Sun Lei,Yan Qun,Guo Tailiang,Zhang Yongai
Thin-film encapsulation (TFE) is essential and challenging for flexible organic/quantum dot light-emitting diodes (OLEDs/QLEDs). In this work, SiO 2 nanoparticles were added into the NEA 121 polymer (s-NEA) to prolong the permeation pathways, showing good barrier property and high optical transparency. With increasing the concentration of SiO 2 nanoparticles up to 20 mg/ml, the value of water vapor transmission rate (WVTR) decreased. A single s-NEA layer with silica concentration of 20 mg/ml and thickness of ~ 75 µm exhibited WVTR of 2.5 × 10 −3 g/m 2 /day and light transmittance of above 80%. Al 2 O 3 thin films fabricated using atomic layer deposition were inserted between s-NEA layers to form dyad-style Al 2 O 3 /s-NEA multilayers. The Al 2 O 3 (60 nm)/s-NEA (20 µm) multilayers with 3 units exhibited WVTR of 2.6 × 10 −5 g/m 2 /day and consistently demonstrated a significantly extended QLED lifetime.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Han Jia,Xuehao Zhang,Qiuxia Wang,Yingbiao Xu,Lingyu Zhang,Jiajun Dai,Yuanbo Wang,Qiuyu Xie,Haidong Jia,Lin Song
Wormlike micelles (WLMs) with superior viscoelasticity exhibited great potential application in petroleum industry. Compared with polymer systems, the relatively low viscoelasticity of WLMs should be further improved effectively. In this study, the amphiphilic Janus-SiO 2 nanoparticles (JAnC NPs, n represents the carbon atoms number of modified alkyl chain) were successfully fabricated, which were verified by Fourier transform infrared spectra and water contact angle measurements. Then the effects of additional JA3C NPs on the viscoelasticity of WLMs solutions formed by stearyltrimethylammonium bromide/sodium salicylate were systemically explored via rheology behavior and cryo-TEM pictures. Compared with original isotropic SiO 2 NPs, the amphiphilic JAnC NPs showed greater ability to improve the WLMs viscoelasticity. To explore the enhanced mechanism, the zeta potential of STAB/SiO 2 dispersions and the viscosity of WLMs formed by various surfactants with additional JAnC NPs were studied in the controlled experiments. In addition, a mathematical model was employed to calculate the quantity of junctions between micelles and NPs in different WLMs/NPs systems to confirm the proposed mechanism. This work firstly investigated the effects of the novel Janus-SiO 2 NPs on the WLMs viscoelasticity.
研究领域:
材料科学
·
石油工程
·
胶体与界面化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Liping Du,Binfei Li,Teng Lu,Boliang Li,Zhaomin Li,Jiqian Wang
To address problematic low reservoir recovery rates, a new porous SiO 2 aerogel nanosuspension (NS) with emulsifying effects was developed, and its microstructure and flow characteristics were analysed with physical property and rheological tests. Moreover, macro- and microlevel flooding experiments were carried out to explore the mechanism for enhanced oil recovery (EOR). The results showed that the final recovery rates were 58.23% and 60.68% with 0.8 PV NS and NS foam slug, respectively, which were 10.03% and 13.62% higher than those of secondary oil recovery. Oil-water emulsions with different emulsification degrees were generated after sufficiently oscillating the NS and condensate oil mixture. NS flooding exhibited evident nonpiston characteristics in the early stage, and particles were transferred from water into the oil phase, which resulted in differential emulsification of the oil. The oil flow status was altered from flakes to droplets due to emulsification and the changing passage cross-section caused by particle accumulation. With NS foam flooding, the oil was first replaced by coherent large bubbles and then migrated under the effects of multiple systems. A particle circumfluence layer around the foam absorbed oil to generate an adhesive oil film.
研究领域:
石油工程
·
材料科学
·
流体力学
✓ 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）