Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 25
·9816-9821
·
IF 8.262
Li Cheng,Qing Chang,Yu Chang,Nannan Zhang,Changyuan Tao,Zhaona Wang,Xing Fan
Hierarchical forest-like photoelectrodes were prepared by assembling nano-ZnO on an array of micro-metal dendrites, aiming to demonstrate the idea of highly efficient photon-harvesting inside a biomimetic dendrite structure. Via a facile aqueous electrochemical deposition process, the metal dendrites were deposited on both flat and wire substrates with different alignments, showing wide adaptability. A strong, broadband anti-reflection effect was observed, owing to the diffuse reflection inside the microdendrites. By increasing the dendrite height, the overall reflectivity of the metal electrode can be reduced from 75% to 45%, which could be further reduced to 12% after combining with acicular-leaf-like ZnO nanoarrays. Its applications in light-driven water splitting were successfully demonstrated. Taking advantage of the forest-like photoelectrode, we have artificially constructed an efficient photo-electrochemical system similar to plants in a forest, with photons harvested by the crown-like photoanodes in the sunshine, and synthetic reactions driven by the root-like electrode in the shadow.
研究领域:
材料科学
·
纳米科技
·
光电化学
·
可再生能源
·
仿生学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 19
·11715-11721
·
IF 4.036
Baokang Zou,Yipeng Zhan,Xiuli Xie,TongTong Zhang,Runkai Qiu,Fangming Zhu
Two salalen titanium(IV) complexes ((H-salalen)TiCl2 and (F-salalen)TiCl2) containing hydrogen and fluorine respectively on the phenolate ring close to the imine were synthesized for the copolymerization of ethylene with 1-octene to prepare poly(ethylene-co-1-octene) in the presence of methylaluminoxane (MAO). The (F-salalen)TiCl2/MAO showed higher catalytic activity and better copolymer characteristics such as a higher molecular weight, narrower molecular weight distribution, and higher 1-octene incorporation than (H-salalen)TiCl2/MAO, which revealed that the electron-withdrawing conjugated effect introduced by fluorine substituents led to improvements on catalytic performance and thermal stability. The influences of copolymerization conditions including temperature, Al/Ti molar ratios and comonomer feed ratios on the copolymerization behavior of (F-salalen)TiCl2/MAO and the copolymer microstructure were investigated in detail. Under the activation of MAO, the (F-salalen)TiCl2 could produce ultrahigh molecular weight poly(ethylene-co-1-octene) with 1-octene incorporation ratios in the range of 0.9–3.1 mol% and exhibit relatively high activity. It could be inferred that long ethylene sequences in the copolymer were segregated by the isolated 1-octene units based on the 13C NMR characterization of the copolymer. Moreover, the thermal properties and crystallization of copolymers were determined by DSC and XRD and correlated to the ethylene sequence length distribution. The reactivity ratios calculated by the triad distribution in 13C NMR revealed the random comonomer distribution in the copolymer chain.
研究领域:
高分子化学
·
配位聚合
·
催化化学
·
材料科学
·
高分子物理
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Dan Baohui,Mahmood ul Haq,Salah Ud Din,Shabab Hussain,Shao Wenyi,Wu Jingmin,Chi Hanwen,Zhizhen Ye,Liping Zhu
The SF 6 gas in gas-insulated switchgear (GIS) systems decomposes into SO 2 F 2 , SOF 2 , SO 2 , and H 2 S under abnormal conditions such as partial discharge. The detection of these decomposition gases with high sensitivity is essential for the safe operation of GIS devices. Herein, we report the synthesis of cerium oxide and multiwalled carbon nanotube composite (CeO 2 @MWCNTs). The CeO 2 @MWCNTs composite was characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy , X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis. The CeO 2 @MWCNTs composite sensor provided a response value of 7.7 at 100 ppm of SO 2 F 2 at a low operating temperature (50 °C), and the response and recovery features of the CeO 2 @MWCNTs composite sensor were recorded at 43 and 28 s, respectively. Moreover, the composite sensor exhibited excellent stability after two months. The developed CeO 2 @MWCNTs composite sensor can offer an exceptional platform for gas sensing applications in diverse fields.
研究领域:
材料科学
·
气体传感技术
·
电力设备监测
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纳米复合材料
·
环境监测
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Jiajie Yu,Muzhong Shen,Siyu Liu,Feng Li,Dongping Sun,Tianhe Wang
In this paper, we describe a simple technique for direct growth of gold nanoparticles (GNPs) into a nanostructured porous alumina layer on conductive glass slide (PAOCG). PAOCG was attached firmly with a small piece of steel and was then immersed in a HAuCl 4 solution. Electro-induced electrons from steel were employed to reduce AuCl 4 − on PAOCG. The galvanic replacement reaction (GRR) was adopted as the fundamental mechanism for reducing metal precursors. This mechanism was further studied by open circuit potential-time (OCP-t) experiment and the result demonstrated that steel induced the continuous proceeding of this reaction. This strategy presents a simple and general protocol for preparation of metal nanoparticles (MNPs) on conductive glass substrates. The SERS properties of Au/PAOCG were investigated using aqueous crystal violet (CV) and 4-mercaptopyridine (4-Mpy) as probe molecules. Au/PAOCG allowed as low as 10 −9 M CV and 10 −8 M 4-Mpy to be detected. The reusability of this substrate was achieved by measuring the SERS spectrum of the probe molecules followed with a 400 °C heat treatment for 10 min to remove the residuals. This substrate could be reused for at least ten cycles without any significantly reduced SERS performance. Therefore, this surface can serve as a portable, durable and reusable SERS substrate and has a potential for commercial applications.
研究领域:
材料科学
·
分析化学
·
纳米技术
·
生物传感
·
表面科学
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 30
·期 9
·2313-2320
·
IF 2.162
Hui Zhao,Si-Qi Zhao,Guo-Hua Hu,Qun-Chao Zhang,Yang Liu,Chong-Xing Huang,Wei Li,Tao Jiang,Shuang-Fei Wang
A facile method was developed to synthesize a new type of polyhedral oligomeric silsesquioxane (POSS). It contained a single amine group and seven aliphatic moieties on its corners. FT-IR, 1 H-NMR, 13 C-NMR, 13 C- 1 H COSY, and 1 H- 1 H COSY confirmed that cages with eight corners were the main part of the product. This new POSS was used to modify the structure of hexamethylene diisocyanate trimer and then copolymerized with hexamethylene diisocyanate and poly (tetramethylene glycol) to get a serious of waterborne polyurethane (WPU)/POSS hybrid materials with low dielectric constants for microelectronics applications. The results showed that POSS particles were uniformly dispersed in the WPU dispersions. The WPU/POSS films did not show any macrophase separation, even when the POSS content was as high as 16%. As the POSS content increased from 0% to 16%, the tensile strength was increased from 2.3 to 7.3 MPa, the dielectric constant was decreased from about 2.9 to 2.0, and the thermal stability of the WPU/POSS was also improved.
研究领域:
高分子科学
·
材料化学
·
纳米复合材料
·
电子封装材料
·
功能高分子
✓ 已验证
DOI
高影响因子
THIN SOLID FILMS
·
2018
·
IF 1.939
Yanqi Lv,Yanhong Li,Hongxia Sun,Yi Guo,Yanmei Li,Jinkun Tan,Xingfu Zhou
Crystalline yttrium-doped rutile TiO 2 nanorod arrays were synthesized and successfully implemented as a photoanode of perovskite solar cells . Study shows that yttrium was successfully doped and TiO 2 band gap changes from 3.07 eV to 3.02 eV. A positive shift of 100 mV in the flat-band potential (V fb ) was observed in Y-doped rutile TiO 2 nanorods. A power conversion efficiency of 7.95% and a photocurrent density of 15.13 mA/cm 2 were obtained for the doped sample. The photocurrent density is 1.47 times higher than that of the un-doped device. Incident photon-to-current conversion efficiency shows Y-doped device has a clear increase in quantum efficiency in the visible light range from 450 and 750 nm. Open circuit voltage decay measurements demonstrate the superior ability of Y-doped TiO 2 nanorod for separating electrons and holes and decreasing the recombination events. The improved performance is possibly attributed to the enhanced electron injection and transfer efficiency caused by a positive shift in V fb and a reduction in charge recombination. This study opens a door toward the improvement of photocurrent density of perovskite solar cell via an element doping route.
研究领域:
材料科学
·
纳米科技
·
能源化学
·
光电子学
·
半导体物理
·
可再生能源
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Zhenzhen Jia,Qiuxin Liu,Jiatang Hu,Shiyu Li,Hujunjie Chen
Water hypoxia and metal pollution are commonly co-existed in urbanized estuaries. This study focuses on the effect of an extended dissolved oxygen (DO) full-life dynamics (86 days) on metal behavior across the sediment-water interface through laboratory microcosms from two typical zones in Pearl River Estuary. Combining our time-series results of concentrations and fluxes, it showed that Co, Ni, and Zn consistently presented a release-precipitation-release trajectory with an oxic-hypoxic-anoxic-reoxic transition, characterized with highly variable behavior in the hypoxic-anoxic hotmoments. In parallel, changing DO dynamics significantly activated a repartitioning process of Co, Ni, and Zn among several species and elevated their risk in sediments, promoting the formation of more labile species in the 0–10 mm hotspots, where metals sensitively responded. Over DO transition, metal cycling was tightly co-related with Fe, Mn, and S elements. It was found that Mn was dominated in low oxygen-hypoxic period, but switched to S and Fe in anoxic stage, limiting sustained metal liberation to overlying water. Enlarging this experiment to practice, released Zn fluxes from sediments in hypoxic summer could contribute about ∼2.0% to their stocks in water column, while increase to 20% (1 m bottom water) in highly-stratified zones. This study has certain significance in understanding the long-term metal behavior and fate in estuarine regions, even lakes and reservoirs.
研究领域:
环境科学
·
地球化学
·
水生生态学
·
污染生态学
·
生物地球化学
·
环境毒理学
·
河口学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Xiangyang Zhuang,Yao Zhang,Lingxiao He,Yunfeng Zhu,Quan Shi,Quan Wang,Guanzhou Song,Xiaoxiao Yan,Liquan Li
Overheating caused by exothermic effect of magnesiothermic reduction reaction is usually considered as a drawback in preparing porous silicon anode materials for Li-ion batteries. However, in the present work, thermal effect is available in facile preparation of macroporous Si by tabletting pretreatment . The released heat in magnesiothermic reaction is easily accumulated on the tablet with high density, leading to the collapse of the mesoporous structure of the precursor and formation of uniform macroporous silicon . Such macroporous silicon shows a higher initial Coulomb efficiency (86.5%) and enhanced cycling stability in comparison with mesoporous silicon prepared without tabletting treatment. XRD analysis indicates that the reaction temperature decreases to 430–435 °C (based on set temperature), much lower than that of the reaction without pretreatment. Since the structure of product has less dependency on precursor, a wide variety of precursors can be used to synthesize macroporous silicon, e.g. low cost biosilica. Being ascribed to low reaction temperature, heating rate insensitivity, less dependency on precursor, enhanced cycling performance and high initial Coulomb efficiency of the Si products, the modified magnesiothermic reduction method is promising for application in fabricating Si anode.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
无机合成
·
功能材料
·
电池技术
✓ 已验证
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2017
·
IF 4.075
Guangshun Wu,Lei Chen,Li Liu
Effects of silane and silica enrichment of carbon fibers (CFs) on interfacial properties of methylphenylsilicone resin (MPSR) composites were investigated. CFs were oxidized, grafted with 3-aminopropyltriethoxysilane (APS) and then modified with silica nanoparticles prepared by the sol-gel polymerization of tetraethoxysilane (TEOS). Chemical structures of CFs were characterized by confirming the successful grafting. Scanning electron microscopy (SEM) showed a uniform distribution of silica nanoparticles on the CFs surface. The interlaminar shear strength (ILSS) and impact toughness of silanized CF (CF-Siloxane) composites were 12.05% and 7.46% higher than those of untreated composites. However, ILSS and impact toughness of the hybrid fiber (CF/Si) composites obtained from the hydrolysis of different concentrations TEOS improved significantly, especially for grafting silica enrichment with the TEOS concentration of 0.05 mol/L (CF/Si0.05), increasing 45.64% in ILSS and 29.59% in impact properties. Moreover, the hydrothermal aging resistance was also improved greatly. Meanwhile, functionalization processes did not decrease fiber tensile strength .
研究领域:
复合材料科学
·
高分子材料
·
表面改性
·
界面工程
·
材料化学
✓ 已验证
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2021
·
IF 7.328
Hongyuan Zhao,Bo Li,Runqiang Liu,Yuqi Chang,Hongliang Wang,Lin Zhou,Sridhar Komarneni
Herein, a cost-effective and scalable ultrasound assisted approach was proposed to prepare the nanocomposite of halloysite nanotubes/zirconia/carbon black (Hal/ZrO 2 /CB), which was used to fabricate a novel electrochemical sensor for the highly sensitive determination of methyl parathion (MP). In the Hal/ZrO 2 /CB nanocomposite, Hal with large specific surface area and numerous active sites could enhance the adsorption capacity and accelerate the redox reaction of MP; ZrO 2 nanoparticles with high affinity toward the phosphate group could contribute to good recognition performance for MP; CB nanoparticles with good dispersibility formed an interconnected pearl-chain-like conductive network. Benefitting from the synergistic effect of the three components, the Hal/ZrO 2 /CB/GCE (glassy carbon electrode) sensor showed a remarkably low detection limit of 5.23 nM in a good linear MP detection range of 0.01–10 μM. The Hal/ZrO 2 /CB/GCE sensor possessed a pretty decent practicality with satisfactory RSD and recovery results for the determination of MP in peach, pear, and apple juices. Therefore, the Hal/ZrO 2 /CB/GCE sensor has important implication on the quite sensitive detection of MP.
研究领域:
分析化学
·
纳米科学与技术
·
环境监测
·
食品安全
·
电化学传感
·
农药残留检测
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2015
·
IF 6.217
Jian Zhi,Houlei Cui,Angran Chen,Yian Xie,Fuqiang Huang
Dye-sensitized solar cells (DSSCs) on flexible plastic substrates usually suffer from a slower electron diffusion rate and insufficient surface area due to no sintering process . Therefore, the conversion efficiency (ƞ) of such flexible DSSCs is normally below 6%. Here, the highly flexible DSSCs with enhanced performance are fabricated at room temperature, employing 3D graphene decorated nanocrystalline TiO 2 films (3DGT) as anode on plastic substrates. Owing to the enhanced charge transportation and increased surface area from 3D conductive graphene skeleton, the 13 μm-thick 3DGT-0.85 (0.85 wt% 3D graphene plus TiO 2 nanoparticles) anode achieves a power conversion efficiency of 6.41%, which is 56% higher than pristine TiO 2 based anode. This efficiency is among the highest values for the previously reported TiO 2 photoanodes on plastic substrates.
研究领域:
材料科学
·
纳米科技
·
能源化学
·
光电转换
·
柔性电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2015
·Vol. 54
·期 3
·368-380
·
IF 3.113
Jingang Li,Yixin Xiang,Sixun Zheng
In this contribution, we reported the synthesis of a hyperbranched block copolymer composed of poly(ε-caprolactone) (PCL) and polystyrene (PS) subchains. Toward this end, we first synthesized an α-alkynyl- and ω,ω′-diazido-terminated PCL- b -(PS) 2 macromonomer via the combination of ring-opening polymerization and atom transfer radical polymerization. By the use of this AB 2 macromonomer, the hyperbranched block copolymer ( h -[PCL- b -(PS) 2 ]) was synthesized via a copper-catalyzed Huisgen 1,3-dipolar cycloaddition (i.e., click reaction) polymerization. The hyperbranched block copolymer was characterized by means of 1 H nuclear magnetic resonance spectroscopy and gel permeation chromatography. Both differential scanning calorimetry and atomic force microscopy showed that the hyperbranched block copolymer was microphase-separated in bulk. While this hyperbranched block copolymer was incorporated into epoxy, the nanostructured thermosets were successfully obtained; the formation of the nanophases in epoxy followed reaction-induced microphase separation mechanism as evidenced by atomic force microscopy, small angle X-ray scattering, and dynamic mechanical thermal analysis. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54 , 368–380
研究领域:
高分子化学
·
材料科学
·
纳米结构功能材料
·
聚合物自组装
·
热固性树脂改性
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）