RSC Advances
·
2015
·Vol. 5
·期 117
·96483-96487
·
IF 3.84
Ruike Li,Meicheng Li,Yingfeng Li,Pengfei Fu,Younan Luo,Rui Huang,Dandan Song,Joseph Michel Mbengue
Metal-assisted chemical etching is a very popular method of fabricating silicon nanostructures. For the dissolution and recrystallization of Ag and the inertia of Au, we present a co-catalytic mechanism of silicon etching using non-overlapping Au and Ag nanofilms. Meanwhile, two kinds of novel nanostructures are obtained by changing the relative positions of the two nanofilms. The results show that regardless of whether the Ag or Au nanofilm is the upper layer, the Ag nanofilm will first react to etch the silicon substrate into silicon nanowires (Si NWs). Afterwards, the Au nanofilm will re-etch the Si NWs into thick pillars (Ag upper) or ultrathin porous Si NWs (Au upper). It should be noted that the vertical etching rates of the two layers are not observably different, in contrast to when the Au and Ag nanofilms are used separately, in which the vertical etching rate of the Ag nanofilm is much higher than that of the Au nanofilm. This occurs because the subsequent re-etching process by the Au nanofilm is conducted at multiple surfaces because Au can generate excessive holes during the decomposition of hydrogen peroxide. Furthermore, this study presents a feasible method for the fabrication of individual, thick (∼200 nm) silicon pillars and ultrathin (∼25 nm) porous Si NWs. These insights are significant for the syntheses of many nanostructures.
研究领域:
材料科学
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纳米技术
·
化学工程
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Zhongling Cheng,Yi Hu,Keshi Wu,Yusheng Xing,Peng Pan,Liyuan Jiang,Jieting Mao,Changke Ni,Zixi Wang,Mengmeng Zhang,Yaru Zhang,Xiaofeng Gu,Xiangwu Zhang
Silicon anodes are one of the most promising candidate materials for next-generation lithium-ion batteries because of their high theoretical capacity and natural abundance. Unfortunately, the poor conductivity of silicon and large volume expansion (>400%) during the cycle restrict its commercialization. Herein, we combine Si with stable TiO 2 and electrically conductive Ti 2 O 3 to significantly increase the capacity and cycle stability of the Si-based anodes. The preparation of a Si/TiO 2 /Ti 2 O 3 -Carbon Nanofiber (denoted as STTC) composite via mechanical blending, electrospinning and subsequent carbonization of Si, TiO 2 , and polyacrylonitrile (PAN). This material exhibits a reversible specific capacity of 924 mAh g −1 after 500 cycles of 1 A g −1 current density. Moreover, it also exhibits excellent rate performance even at current densities of 6 A g −1 . The outstanding electrochemical performance can be ascribed to Ti 2 O 3 generates in the carbonization process has high ion diffusivity and electrical conductivity. Furthermore, the disordered frame of TiO 2 /Ti 2 O 3 forms voids, which can alleviate the volume expansion of silicon, maintain the electrode integrity during charge and discharge, and form a thin and stable solid electrolyte interphase (SEI). Additionally, the conductive frame of carbon nanofibers also significantly improves the ion and electron conductivity of the complete electrode.
研究领域:
材料科学
·
电化学
·
纳米技术
·
能源存储
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DOI
高影响因子
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
·
2026
·Vol. 131
·期 3
·e2025JE009644
·
IF 3.7
Xiaolong Guo,Peixin Du,Hongmei Liu,Jiacheng Liu,Shangying Li,Xinyi Xiang,Shun Wang,Peng Yuan
Poorly ordered Al/Si phases are widely distributed across the surface of Mars, among which allophane and amorphous silica are the two main constituents. Both allophane and amorphous silica can form in Al-Si systems through surface chemical weathering or subsurface hydrothermal alteration of volcanic materials. Nevertheless, our comprehension of the products derived from Al-Si hydrolysis systems remains poorly constrained. Hydrolysis experiments were conducted on Al-Si systems across an unprecedentedly wide range of Si/(Al + Si) molar ratios ( n , 0 ≤ n ≤ 0.9), followed by characterizing the products using multiple techniques. At n ≤ 0.1, the products consist predominantly of Al 30 (an Al polycation with a Keggin structure) and poorly ordered Al hydroxides. The introduction of Si resulted in formation of a small amount of proto-allophane. At n = 0.2 and 0.3, poorly ordered materials were still dominant, along with the presence of well-crystallized bayerite and gibbsite. The proto-allophane increased in quantity and began to assemble into allophane. At n = 0.5, well-crystallized minerals were absent and allophane dominated the product. At n = 0.7, the amount of allophane decreased significantly and at n = 0.8 and 0.9, allophane was probably absent, although proto-allophane still formed. Meanwhile, an increasing amount of amorphous silica was formed. X-ray diffraction, Fourier transform infrared, and VNIR provide information for differentiating Al-rich phases and Si-rich phases but show limited capability in identifying poorly ordered Al/Si-rich phases. NMR is powerful for identifying poorly ordered Al/Si phases, although widespread iron on the martian surface and the large instrument pose challenges to its application on Mars.
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高影响因子
MOLECULES
·
2023
·Vol. 28
·期 10
·4082
·
IF 4.6
Jinbo Yang,Xiangxue Cao,Lanfeng Wei,Jianshu Zhang,Jinli Zhang,Ping Liu,Liang Xu,Pengfei Li
Herein, a four-coordinated organoboron compound, aminoquinoline diarylboron (AQDAB), is utilized as the photocatalyst in the oxidation of silane to silanol. This strategy effectively oxidizes Si–H bonds, affording Si–O bonds. Generally, the corresponding silanols can be obtained in moderate to good yields at room temperature under oxygen atmospheres, representing a green protocol to complement the existing preparation methods for silanols.Keywords:photocatalytic oxidation;silane;silanol;aminoquinoline diarylboron
研究领域:
有机化学
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光化学
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催化
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绿色化学
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DOI
高影响因子
ENVIRONMENTAL RESEARCH
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2025
·
IF 7.7
Xiuqiong Fu,Qian Wan,Yong Fan,Yimin Zhang,Ruobing Zhang,Zhijie Guo
The preparation of geopolymers from tailings rich in quartz typically requires activation to enhance final strength, though the underlying mechanism remains unclear. Quartz, as a common inert gangue mineral in tailings, was selected as the research subject. Quartz with varying reactivity was prepared through mechanical activation of different particle sizes and used for geopolymer synthesis, aiming to elucidate the strengthening mechanism of activated quartz on geopolymers. When the activation time was identical, quartz particles of different sizes exhibited the same soluble silicon content. However, due to the increased surface-active groups after activation, geopolymers derived from larger quartz particles (5–8 mm) achieved compressive strengths of 57.24–64.73 MPa, while those from smaller particles (0.08–0.12 mm) only reached 43.83–50.42 MPa. After activation, the main active groups on the quartz surface were the Q n (n = 1, 2, 3) structures containing non-bridging oxygens and silicon radicals. The Q 1 and Q 2 structures mainly provide soluble silicon in geopolymerization and have little effect on the strength of the geopolymer. While the Q 3 structure can combine with the geopolymer gel through Si-O-Si bonds, reducing the porosity at the interface between quartz and geopolymer, significantly enhancing the strength of geopolymer. The results indicate that, compared to soluble silicon content of quartz, the content of active groups on its surface is the main factor influencing the performance of geopolymer. For the activation of tailings, increasing the reactivity of their surface is more effective in improving geopolymer strength than enhancing the leaching of soluble silicon and aluminum through overall activation.
研究领域:
材料科学
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土木工程
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矿物加工
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表面化学
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聚合物科学
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DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Yongsheng Ren,Shun Ueda,Kazuki Morita
Based on (i) the low liquidus temperature of Si–Cu systems, (ii) low solubility of Cu in solid Si, and (iii) a strong affinity of Zr to B for the enhanced boride formation, a novel method to remove B from Si using Zr as a trapping agent via a Si–Cu solvent was developed in this study. B-bearing polygonal ZrBx precipitations found at the bottom of test samples were confirmed as ZrB2 by electron probe microanalysis. Thermodynamic analysis revealed that the solubility products of ZrB2 in a Si–Cu melt were 2.50 × 10–12 (1258 K, Si-57.0 atom % Cu) and 4.11 × 10–12 (1345 K, Si-50.0 atom % Cu). Finally, the compositions of Si–Cu alloys that can form stable ZrB2 particles were estimated by calculating the solubility products of ZrB2 and the equilibrium contents between B and Zr at different corresponding liquidus temperatures. The proposed method provides the potential for B removal via Si–Cu solvent refinement to realize the large-scale production of solar-grade silicon, thereby overcoming the key limitation to the sustainable utilization of solar energy.
研究领域:
材料科学
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冶金学
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半导体材料
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回收技术
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热力学
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DOI
高影响因子
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
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2024
·Vol. 129
·期 4
·e2023JE008031
·
IF 3.9
Xinyi Xiang,Peixin Du,Binlong Ye,Hongling Bu,Dong Liu,Jiacheng Liu,Jian Hua,Xiaolong Guo
Ferrihydrite, a nanocrystalline iron (oxyhydr)oxide mineral, is widely distributed in soils and sediments on Earth and is probably an important component and/or precursor of widespread nanophase iron minerals on Mars. Terrestrial ferrihydrite often co-occurs with amorphous silica and/or contains a certain amount of Si in its structure. However, it remains ambiguous how environmental Si concentration affects the formation-evolution and structure-spectral features of ferrihydrite in the Fe(III)-Si systems. To this end, hydrolysis experiments were carried out for Fe-Si systems at an unprecedentedly wide range of initial Si/(Fe + Si) molar ratios (0–0.80), followed by characterizing the products detailly. X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, Mössbauer spectroscopy, and transmission electron microscopy results showed that at Si/(Fe + Si) molar ratios ≤0.30, the main phase of the products was ferrihydrite, of which the unit cells enlarged, the crystallinity decreased, and the existing state of Fe changed with increased Si contents; at Si/(Fe + Si) molar ratios ≥0.40, ferrihydrite was no longer formed and a novel amorphous Fe-O-Si phase was instead obtained, with the excess Si forming amorphous silica. The visible and near-infrared spectroscopy, the most powerful tool to detect hydrous minerals on the surface of Mars at global or regional scales, showed weakness in identifying ferrihydrite-like materials obtained in the Fe-Si systems. Raman spectroscopy can identify ferrihydrite and Si-containing ferrihydrite but cannot differentiate between them. Mössbauer spectroscopy showed great potential in both identifying and differentiating between ferrihydrite and Si-containing ferrihydrite, and thus can be used to characterize the poorly ordered iron (oxyhydr)oxides on Mars. Key Points Hydrolysis experiments of Fe(III)-Si systems were performed at an unprecedentedly wide range of initial Si/(Fe + Si) molar ratios (0∼0.80) The environmental Si concentration controls the formation and evolution of ferrihydrite in the Fe(III)-Si systems Mössbauer spectroscopy shows great potential in identifying and differentiating between ferrihydrite-like materials Plain Language Summary On the surface of ancient Mars where liquid water was available, Fe-Si hydrolysis systems were likely common as a result of the high abundances of Fe and Si in the crust of Mars. By performing hydrolysis experiments of Fe-Si systems at an unprecedented wide range of Si/(Fe + Si) molar ratios, we found that the hydrolysis products of Fe-Si systems varied among combinations of ferrihydrite, Si-containing ferrihydrite, an unknown Fe-O-Si phase, and amorphous silica. We also found that the visible and near-infrared reflectance spectroscopy, the most powerful tool to remotely detect hydrous minerals on the surface of Mars at global and regional scales, showed weakness in identifying ferrihydrite, Si-containing ferrihydrite, and the novel Fe-O-Si phase; Raman can be used to identify ferrihydrite-like materials but cannot be used to differentiate between ferrihydrite and Si-containing ferrihydrite; mid-infrared spectroscopy can differentiate ferrihydrite from Si-containing ferrihydrite and the novel Fe-O-Si phase; Mössbauer spectroscopy (recorded at varied temperatures) provided clues to identifying and further differentiating between ferrihydrite-like materials and thus holds great potential for detecting Fe/Si-rich phases on the surface of Mars.
研究领域:
地质学
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行星科学
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矿物学
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DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 13
·5170
·
IF 4.6
Jinyuan Zhu,Yingying Zhu,Yifan Zhou,Chen Wu,Zhen Chen,Geng Chen
The direct or indirect discharge of organic pollutants causes serious environmental problems and endangers human health. The high electron–hole recombination rate greatly limits the catalytic efficiency of traditional TiO2-based catalysts. Therefore, starting from low-cost activated carbon (AC), a photocatalyst (F-Si-TiO2/AC) comprising fluorine (F)- and silicon (Si)-doped TiO2loaded on AC has been developed. F-Si-TiO2/AC has a porous structure. TiO2nanoparticles were uniformly fixed on the surface or pores of AC, producing many catalytic sites. The band gap of F-Si-TiO2/AC is only 2.7 eV. In addition, F-Si-TiO2/AC exhibits an excellent adsorption capacity toward methyl orange (MO) (57%) in the dark after 60 min. Under the optimal preparation conditions, F-Si-TiO2/AC showed a significant photodegradation performance toward MO, reaching 97.7% after irradiation with visible light for 70 min. Even under the action of different anions and cations, its degradation efficiency is the lowest, at 64.0%, which has good prospects for practical application. At the same time, F-Si-TiO2/AC has long-term, stable, practical application potential and can be easily recovered from the solution. Therefore, this work provides new insights for the fabrication of low-cost, porous, activated, carbon-based photocatalysts, which can be used as high-performance photocatalysts for the degradation of organic pollutants.Keywords:F-Si-TiO2;methyl orange;visible light;doped;electronic cage
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
Advanced Composites and Hybrid Materials
·
2022
·Vol. 5
·期 2
·1362-1375
·
IF 11.806
Wang Deng,Wang Rui,Huang Kai,Lei Ming,Tang Haolin
The Si-P nanohybrids, as an underlying candidate for the anode material of the next-generation lithium-ion batteries (LIBs), possess a high theoretical specific capacity of 2900 mAh g −1 but decays rapidly owing to the large volume change during lithiation/delithiation. Meanwhile, two-dimensional transition metal carbides (MXenes) with outstanding conductivity and specific crystal structure have been revealed with a relative low Li + diffusion barrier, which exhibits underlying application prospects in the area of energy storage and can be particularly utilized as the conductive matrix for realizing the outstanding performance of lithium storage. Herein, we employ an MXenes (Ti 3 C 2 T x )-buffer strategy to improve the electrochemical properties of the traditional Si-P anode by a relatively simple mechanical ball-milling method. Obvious chemical bonds between Si-P and Ti 3 C 2 T x have been confirmed for as-prepared Si-P/Ti 3 C 2 T x composites, where P nanolayer acts as an intermediate layer and guarantees the composite integrity and the tight contact between red phosphorus, Si, and Ti 3 C 2 T x matrix. Moreover, the Si-P/Ti 3 C 2 T x composite electrode, in comparison with Si-P composite and Si, exhibits an enhanced rate performance (632.4 mAh g −1 at 5A g −1 ) and a higher reversible capacity (980.8 mAh g −1 after 500 cycles at 500 mA g −1 ), indicating it’s a promising candidate for advanced LIBs anode. Graphical abstract The high-performance chemically bonded double-conductive protective layer lithium-ion battery anode was developed by mechanical ball-milling strategy.
研究领域:
材料科学
·
能源存储
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Shengpeng Jiang,Jiahui Wu,Bingrong Ma,Meihong Liu,Sanchuan Yu,Congjie Gao
This work focused on the construction of an acid-resistant composite nanofiltration membrane with the selective layer of bulk cross-linked hydroxyethyl cellulose (HEC)-silica and a support of porous polypropylene . Membranes were fabricated through in-situ sol-gel reaction and slot-die coating method employing tetraethyl orthosilicate (TEOS) as the silica precursor and cross-linking agent of HEC. Membrane structure and performance were tuned by controlling the hydrolysis time of TEOS and differentiating TEOS and HEC contents, and systematically characterized in terms of physico-chemical property, permeation attribution and acid stability. It was found that membrane performance was strongly correlated with the relative contents of C–O–Si and Si–O–Si bonds of the formed HEC-silica selective layer. High content of C–O–Si bond formed via condensation reaction of HEC and TEOS endowed the selective layer with denser network structure and good rejection ability. Both insufficient and excessive hydrolysis led to a poor rejection ability of formed membrane. The optimized HEC-silica membrane possessed an average pore size of about 1.43 nm within the scope of nanofiltration membrane, a high pure water permeability coefficient of around 10.5 LMH/bar, and a medium rejection of 85.2% to 500 mg/l Na 2 SO 4 aqueous solution at 5.0 bar. No changes in both chemical structure and separation performance occurred with the HEC-silica composite membrane after being soaked in aqueous H 2 SO 4 solution of 4.9 wt% for 7 days, while evident structure destruction and serious performance degradation occurred with the compared polyamide-based commercial membrane NF270. Long-term soaking test using 15.0 wt% H 2 SO 4 aqueous solution for 30 days also demonstrated that the acid resistance HEC silica membrane was comparable with those reported acid stable nanofiltration membranes. Furthermore, the HEC-silica membrane also maintained its water permeation and solute rejection abilities during a 30-day continuous filtration of aqueous solution of 4.9 wt% H 2 SO 4 and 50 mg/l polyethylene glycol fraction (PEG2000). The good acid resistance of the HEC-silica composite membrane was attributed to its bulk cross-linked network structure composed of C–O–Si, Si–O–Si and C–C bonds.
研究领域:
材料科学
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化学工程
·
膜技术
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产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2019
·
IF 3.218
Zheng-Guang Hu,Zhi-Yuan Tan,Zhong Lin,Jun Chen,Fang Sun,Xuyao Tang,Rui-Ting Zheng,Yong-Chong Chen,Guo-An Cheng
Si is one of the most attractive anode materials because of its extremely high theoretical capacity. In this study, we find that the (111) plane of crystalline Si in the anode is still present after 100 cycles and infer that it is the intercalation site of Li + ions. We believe that Li + ions are inserted into the tetrahedral sites of crystalline Si, and the (111) plane of Si collapses; meanwhile, expansion parallel to 〈220〉 crystal orientation occurs. After full lithiation , the crystalline Si is converted to amorphous silicon . In a Si/ composite anode, although the addition of amorphous carbon may improve the cycling performance of Si anode, the activation process is prolonged as the amount of amorphous carbon increased. We determine that amorphous carbon may reduce the diffusion of Li + , which increases the overpotential and results in the lower formation of the saturated Li/Si alloy.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
Journal of Materials Chemistry B
·
2022
·Vol. 10
·期 43
·8996-9007
·
IF 7.571
Xin Zhang,Ning Wang,Yetong Shen,Yang Zhang,Lu Han,Bo Hu
A novel drug loading system, Au@Si–NN–Si@SiO2, is constructed by a layer-by-layer assembly approach. The core Au nanorods serve as the matrix for a near-infrared light (NIR) responsive photothermal feature. Meanwhile, the assembly's middle shell is composed of azobenzene linked silica, which produces free radicals by breaking –NN– bonds at a high temperature brought about by a NIR irradiation-caused photothermal effect, which further triggers the loaded drug release. The outer shell is formed of SiO2 in order to prevent leakage of drug in the middle layer. The fully drug loaded nanocarriers, Au@Si–NN–Si@SiO2-Dox, exhibit an excellent photothermal effect (43%) at a concentration of 170 μg mL−1 under 808 nm NIR laser at 2.3 W cm−2. The antitumor performance of Au@Si–NN–Si@SiO2-Dox was investigated using human colon cancer cells (HCT116) as a model. By combining NIR-triggered drug release, free radical generation and the photothermal effect, the proposed Au@Si–NN–Si@SiO2-Dox exhibits improved antitumor efficiency. By using a dosage of 170 μg mL−1, a cell viability of 17.56% is achieved for HCT116 (5 × 103–1 × 104 cells per well) with 10 min of NIR laser irradiation (808 nm, 2.3 W cm−2). All the results demonstrate that Au@Si–NN–Si@SiO2-Dox exhibits wonderful dosage-dependent antitumor performance and has great potential as a therapeutic agent for tumors or even for use in the clinic.
研究领域:
癌症治疗
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纳米技术
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药学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）