ACTA PHYSICO-CHIMICA SINICA
·
2017
·Vol. 33
·期 7
·1462-1473
·
IF 0.767
HUANG Xue-Hui,SHANG Xiao-Hui,NIU Peng-Ju
Mesoporous SBA-15 with mesopore diameter up to 10.1 nm was prepared by a hydrothermal method, and was further functionalized to obtain different surface properties. Thus-prepared SBA-15 was employed as a template to synthesize rhombohedrally crystallized mesoporous La0.8Sr0.2CoO3
perovskite via a nanocasting method. The surface properties of the SBA-15 were adjusted by treatment with concentrated hydrochloric acid, trimethylchlorosilane (TMCS), and 3-aminopropyltriethoxysilane (APTES). A series of characterization techniques verified that all the synthesized
templates possessed ordered two-dimensional hexagonal mesoporous structure, and the surface was successfully modified with methyl and amino groups. The mesoporous perovskite structure was formed in the samples and the surface properties of SBA-15 significantly influenced the structure and
properties of La0.8Sr0.2CoO3 perovskite oxides. Wide-angle X-ray diffraction patterns suggested that the modified silica templates were conducive to the formation of pure perovskite frameworks with good crystallinity. The catalysts also possessed mesoporous
structure, as confirmed by small-angle XRD patterns, high-resolution transmission electron microscopy images, and nitrogen adsorption analysis. Moreover, the La0.8Sr0.2CoO3 materials synthesized using surface-functionalized templates exhibited relatively higher
catalytic activity and stability in CO oxidation. Complete CO conversion could be achieved at 140°C #xb0;Cusing the thus-prepared La0.8Sr0.2CoO3 materials, and no significant loss in catalytic activity was observed after 100 h of on-stream reaction experiments.
X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, and O2 temperature-programmed desorption experiments revealed that the existence of Co4+, Sr enrichment in the perovskite structure, and high content of adsorbed oxygen species play a critical
role in the enhanced catalytic activity of the catalysts. We also proposed the possible reasons for the effect of surface properties of the silica templates on the structure and properties of the La0.8Sr0.2CoO3 nanomaterials.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Dong Li,Yuexiao Pan,Xunan Wei,Jun Lin
Red phosphors based on Mn 4+ doped fluorides emitting narrow red light under the excitation of blue GaN chips, which can help to improve the luminescence efficiency and color rendering index (CRI) of white light-emitting diodes (WLEDs). In this paper, we carried out a room-temperature synthesis method to obtain a new phosphor of CsNaGe x Sn 1-x F 6 :Mn 4+ (CNGSFM) which contains double-central ions Ge 4+ and Sn 4+ . By controlling the different ratios of the central ions Ge 4+ /Sn 4+ , the contraction and expansion of the matrix lattice CNGSF can be freely changed, which provides a new direction for exploring the trimming method of the lattice effect on the luminescence performance of phosphors. Mn 4+ in CNGSFM shows weak stability and its luminescence quenches fastly in humid environments , so that we explored a facile strategy to improve its humidity resistance. Furthermore, the quenched luminescence of the CNGSFM can be restored through surface modification. Therefore, our results not only establish the tunable mechanism between luminescence performance and microstructure, but also provide a feasible strategy to improve the humidity resistance of Mn 4+ doped double-composite fluoride phosphors.
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
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2023
·Vol. 48
·期 4
·e202200154
·
IF 1.8
Chengcheng Zeng,Zongwei Yang,Jiahui Liu,Ling Ding,Shilong Hao,Feiyan Gong,Zhijian Yang
Low melting point compound MTNP was usually adopt to form co-crystal explosive with CL-20 to reduce sensitivity, and the co-crystal may have the potential of green engineering application. Improving mechanical properties of co-crystals explosive is one of the effective ways to broaden its practical application. In this work, CL-20/MTNP energetic co-crystal was selected to be coated by polydopamine (PDA) and neutral bonding agent (NBA), with enhanced mechanical properties and developed interfacial strength between crystal and binder. The TG-DSC curve showed that thermal decomposition of co-crystal explosives divided into two steps, and the melting point delayed to 210 °C compared with that of MTNP. After surface modification, the storage modulus of PBX was increased by more than 20 % at the temperature range of (25–120) °C, and creep strain was also effectively reduced. The Brazilian and compressive strength of PDA coating samples increased by 69.89 % and 210.53 % respectively, as well as improved elongation, leading to increased fracture toughness. Here, the highlighted modification on the surface of CL-20/MTNP co-crystal can be used as a reference insight to improve the mechanical properties of new explosives.
研究领域:
材料科学
·
爆炸物工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Jing Luo,Chenghao Zhang,Wei Liu,Bingqi Xie,Jisong Zhang
2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) has vital applications in the field of multiphase reaction, especially for the aerobic oxidation of alcohols. Activated carbon (AC) has a porous structure, rigid surface property, and low cost, which was the prominent carrier for TEMPO immobilization to produce the heterogeneous catalyst. However, the brilliant strategy of TEMPO immobilization on AC for long-term aerobic oxidation of alcohols was still challenging. In this work, surface-formylation and reductive amination were conducted to achieve the covalent TEMPO grafting on AC, which opened up a novel routine for surface modification and preparing heterogeneous catalysts based on carbon materials. The catalysts were packed in a micro-packed bed reactor to perform continuous aerobic oxidation of various alcohols. The catalytic performance of benzyl alcohol to benzaldehyde (turnover number: 1160.6, turnover frequency: 99.6 h −1 ) was much superior to those in the literature by using covalently grafted heterogeneous TEMPO catalysts.
研究领域:
化学工程
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
INTEGRATED FERROELECTRICS
·
2017
·
IF 0.457
Si Ma,Aihua Sun,Jianjun Guo,Gaojie Xu,Jianjun Xie
An electrically tunable photonic crystal is developed utilizing crystalline colloidal arrays of particles with low density and high optical contrast. Through modulation of the charge on the surface of particle, and the applied electric field, the peak position of the reflection changes with the increasing voltage. The possibility of using phenolic resin to realize the full color modulation was obtained, which paves a way to develop a novel reflective display with organic nanospheres.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Xiaobing Chen,Ruihang Wen,Gaocan Qi,Hechao Xu,Zhihao Yuan
Lotus leaves usually get the superhydrophobicity from the presence of epicuticular wax on its multilevel micro- and nano-structured surface. It is known that the epicuticular wax is weakly hydrophilic with a contact angle of ∼ 74°, and inorganic elemental sulfur also has a weak hydrophilicity similar to the wax. Inspired by the waxy feature, here we first attempt a superhydrophobicity-harvested strategy by modifying a rough surface with weakly hydrophilic elemental sulfur. The superhydrophobicity of a series of materials including metal hydroxides, oxides, sulfides and chlorides, metals, and even hydrophilic organics, can be achieved by prefabricating their topographic textures combined with elemental sulfur surface modification. DFT calculation suggests that the presence of V S defects on the elemental sulfur coatings can make their rough surfaces have a stronger affinity for O 2 2– than for H 2 O, which allows for the formation of O 2 2– -adsorbed layer on their surface, and thus imbues the hydrophobicity or superhydrophobicity. Our study offers a new and general approach to enhance the surface hydrophobicity via inorganic rather than low surface-energy organic modification.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 11
·5830-5840
·
IF 11.9
Xue Zhao,Mengshan Chen,Yingtang Zhou,Haibo Zhang,Guangzhi Hu
The development of water electrolysis hydrogen production technology is related to the process of large-scale application of green energy, but the high cost of Pt based materials with high catalytic activity that have been commercialized has slowed the pace of industrialization in this field owing to inherent scarcity. In this study, the surface modification technology was used to introduce closo-[B12H12]2− with weak reduction ability into a two-dimensional MXene basal plane to realize the in situ evolution of Pt4+ into snowflake like Pt nanoclusters. The reported MXene/B-Pt enables highly efficient catalytic hydrogen evolution reaction (HER) over the full pH range with an overpotential (η10) as low as 20 mV and 14 mV under basic and acidic conditions, respectively. Overall, the HER performance of MXene/B-Pt surpasses that of commercial Pt/C catalysts by about an order of magnitude improvement in mass activity. For MXene/B-Pt, the snowflake-like Pt nanoparticles not only exposed more active sites, but –Ti and –F enhance the adsorption of active H* on Pt, leading to the high HER activity of MXene/B-Pt. In situ SEIIRAS well demonstrates that whether MXenes are loaded with Pt or not has a significant effect on the HER.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Hongbing Wang,Jianfeng Zhang,Yuping Wu,Huajie Huang,Gaiye Li,Xin Zhang,Zhuyin Wang
Herein we report a simple and facile method to delaminate MXene Ti 3 C 2 multilayers by the assistance of surface modification using aryl diazonium salts. The basic strategy involved the preparation of layered MAX Ti 3 AlC 2 and the exfoliation of Ti 3 AlC 2 into Ti 3 C 2 multilayers, followed by Na + intercalation and surface modification using sulfanilic acid diazonium salts. The resulting chemically grafted Ti 3 C 2 flakes were characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to confirm the presence of the surface organic species. Ultraviolet-visible spectroscopy revealed that surface-modified MXene Ti 3 C 2 sheets disperse well in water and the solutions obey Lambert–Beer’s law. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to demonstrate the morphology and structure of delaminating MXene Ti 3 C 2 flakes. The results indicated that chemical modification for MXene multilayers by aryl diazonium salts induced swelling that conversely weakened the bonds between MX layers, hence leading to large-scale delamination of multilayered MXene Ti 3 C 2 via mild sonication. Advantages of the present approach rely not only on the simplicity and efficiency of the delamination procedure but also on the grafting of aryl groups to MXene surfaces, highly suitable for further applications of the newly discovered two-dimensional materials.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 6
·983
·
IF 3.9
Huajin Qi,Chenyu Wang,Luping Shen,Hongmei Wang,Yuan Lian,Huanxia Zhang,Hongxia Ma,Yong Zhang,Jin Zhong Zhang
α-NiS/g-C3N4nanocomposites were synthesized and used for photocatalytic hydrogen (H2) evolution and tetracycline hydrochloride (TC) degradation. The fabricated nanocomposites were characterized by XRD, XPS, SEM, TEM, UV-vis DRS, TRPL, and PEC measurements. Photocatalytic studies show that the hydrogen generation rate of the 15%-α-NiS/g-C3N4nanocomposite reaches 4025 μmol·g−1·h−1and TC degradation rate 64.6% within 120 min, both of which are higher than that of g-C3N4. The enhanced performance of the nanocomposite is attributed to the formation of a heterojunction between α-NiS and g-C3N4that enhances visible light absorption, promotes the separation and transfer of charges, and inhibits the recombination of carriers. The photocatalytic mechanism of the α-NiS/g-C3N4heterojunction nanocomposite is discussed in terms of relevant energy levels and charge transfer processes.Keywords:photocatalysis;g-C3N4;surface modification;photodegradation;hydrogen evolution
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
CHEMISTRY-A EUROPEAN JOURNAL
·
2023
·Vol. 29
·期 38
·e202300969
·
IF 4.3
Huaqiang Ju,Qing Li Zhu,Min Zuo,Songmiao Liang,Miao Du,Qiang Zheng,Zi Liang Wu
Graphical Tough hydrogels were developed by forming robust hydrazide-Zn 2+ coordination complexes. The mechanical properties of the resultant gels exhibited a notable temperature dependence and thus a good shape-memory ability due to the dynamic nature of coordination bonds. The reactive amine group of the hydrazide enables facile surface modification and functionalization based on Schiff's base reactions. Energy dissipation based on dynamic fracture of metal ligands is an effective way to toughen hydrogels for specific applications in biomedical and engineering fields. Exploration of new kinds of metal-ligand coordinates with robust bonding strength is crucial for the facile synthesis of tough gels. Here a hydrogel toughening strategy based on the formation of robust coordination complexes between the hydrazide ligands and zinc ions is reported. The resultant hydrogels exhibit high strength and toughness at room temperature. Their mechanical properties show temperature dependence due to the dynamic nature of coordination bonds. In addition, the amine group of hydrazides in the gel matrix provides a reactive site for Schiff's base reaction, enabling surface modification without influence on overall mechanical performances of the gel. The hydrazide ligands are easy to synthesize and can coordinate very well with several transition metals. Such a metal-ligand coordination should be suitable to develop tough soft materials with versatile applications.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Xinting Wu,Ning Ren,Gangsheng Tong,Xinyuan Zhu
Ring-opening metathesis polymerization (ROMP) is a powerful method to graft various types of polymer chains to a given surface. While surface-initiated ROMP (SI-ROMP) serves as an efficient tool for surface modification and is therefore widely reported, the method requires grafting (1) the olefin substrate and (2) the metathesis catalyst to the surface prior to the polymerization with multiple synthetic and work up steps. To overcome this difficulty, we proposed the use of the chain-transfer reaction as an alternative method for surface modification. Terminal olefins are grafted to the surface without the need to graft the metathesis catalysts, and polymers with olefin backbones are polymerized and grafted simultaneously via both ROMP and chain transfer (cross-metathesis between olefins from backbones and surfaces). Compared to SI-ROMP, this surface-chain transfer ROMP (SC-ROMP) method avoids grafting the catalyst and growing polymer chains from the surface and could be achieved in a single step. Various types of surfaces like carbon nanotubes, carbon fibers, graphene nanosheets, and silica microspheres are used for demonstration. We envision that this work could bring a convenient and effective solution to surface modification via ROMP.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
Weiguang Kong,Huizhen Wu,Zhenyu Ye,Ruifeng Li,Tianning Xu,Bingpo Zhang
Carbon dots with unique characters of chemical inertness, low cytotoxicity and good biocompatibility, demonstrate important applications in biology and optoelectronics . In this paper we report the optical properties of pH-sensitive carbon dots with different surface modifications. The as-prepared carbon dots can be well dispersed in water by modifying with acid, alkali or metal ions though they tend to form a suspension when being directly dispersed in water. We find that the carbon dots dispersed in water show a new emission and absorption character which is tunable due to the pH-sensitive nature. It is firstly proved that the addition of bivalent copper ions offers a high color contrast for visual colorimetric assays for pH measurement. The effect of surface defects with different modification on the performances of the carbon dots is also explored with a core–shell model. The hydro-dispersed carbon dots can be potentially utilized for cellular imaging or metal ion probes in biochemistry.
研究领域:
生物技术
·
材料科学
·
光学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）