APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Xin Wang,Zhe Zhao,Dingrong Ou,Baofeng Tu,Daan Cui,Xuming Wei,Mojie Cheng
Ag/TiO 2 nanocomposites comprising of Ag clusters on TiO 2 nanocrystal surfaces are of great significance in catalysts and advanced functional materials. Herein a novel method to synthesize Ag/TiO 2 nanocomposites with Ag clusters under 2 nm on TiO 2 nanocrystal surfaces have been developed. The success of this method relies on a silver mirror reaction in toluene, which refers to the reduction of silver-dodecylamine complexes by acetaldehyde in the presence of mono-dispersed TiO 2 nanocrystals. The prepared Ag/TiO 2 nanocomposites have been characterized by FT-IR spectra, UV–vis absorption spectra, X-ray diffraction (XRD) analysis, ultra high resolution scanning electron microscope (Ultra-HRSEM), high resolution transmission electron microscope (HRTEM) and X-ray photoelectron spectra (XPS). Catalytic activity of Ag/TiO 2 nanocomposites is evaluated for the reduction of p -nitrophenol (4-NP) into p -aminophenol (4-AP) by NaBH 4 . Results demonstrate that Ag/TiO 2 nanocomposites have shown an outstanding catalytic activity as well as a good stability in successive reduction of 4-NP. Noticeably, TOF of Ag/TiO 2 -0.75 nanocomposites obtained in this work is the highest among Ag based catalysts previously reported.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2015
·
IF 2.752
Na Zhao,Siwen Li,Xin Zhang,Xinyue Huang,Jinyi Wang,Ruimin Gao,Jianshe Zhao,Junlong Wang
Photocatalytic oxidative desulfurization of dibenzothiophene (DBT) with H 2 O 2 (30%) and Ag/ALa 4 Ti 4 O 15 (A = Ca, Sr and Ba) as the photocatalysts were studied. Ag cocatalyst-loaded ALa 4 Ti 4 O 15 (A = Ca, Sr and Ba) were synthesized by incipient wetness. Reaction time, temperature and the amount of hydrogen peroxide were investigated as the important parameters for optimization of the reaction and a potential removal mechanism of photocatalytic oxidation was proposed. Ag (2 wt%)/CaLa 4 Ti 4 O 15 and Ag (1 wt%)/BaLa 4 Ti 4 O 15 were found to give remarkable catalytic activity and high selectivity for catalytic experiments. Actually, 99.0% and 98.0% of DBT were converted respectively according to the desulfurization tests. Moreover, these two catalysts were characterized by infrared spectroscopy (IR), X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray photoelectron spectrum (XPS).
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
Nano Research
·
2019
·Vol. 12
·期 5
·1187-1192
·
IF 8.515
Zhu Xiyue,Rong Hongpan,Zhang Xiaobin,Di Qiumei,Shang Huishan,Bai Bing,Liu Jiajia,Liu Jia,Xu Meng,Chen Wenxing,Zhang Jiatao
Control of surface structure at the atomic level can effectively tune catalytic properties of nanomaterials. Tuning surface strain is an effective strategy for enhancing catalytic activity; however, the correlation studies between the surface strain with catalytic performance are scant because such mechanistic studies require the precise control of surface strain on catalysts. In this work, a simple strategy of precisely tuning compressive surface strain of atomic-layer Cu 2 O on Cu@Ag (AL-Cu 2 O/Cu@Ag) nanoparticles (NPs) is demonstrated. The AL-Cu2O is synthesized by structure evolution of Cu@Ag core-shell nanoparticles, and the precise thickness-control of AL-Cu 2 O is achieved by tuning the molar ratio of Cu/Ag of the starting material. Aberration-corrected high-resolution transmission electron microscopy (AC-HRTEM) and EELS elemental mapping characterization showed that the compressive surface strain of AL-Cu 2 O along the [111] and [200] directions can be precisely tuned from 6.5% to 1.6% and 6.6% to 4.7%, respectively, by changing the number of AL-Cu 2 O layer from 3 to 6. The as-prepared AL-Cu 2 O/Cu@Ag NPs exhibited excellent catalytic property in the synthesis of azobenzene from aniline, in which the strained 4-layers Cu 2 O (4.5% along the [111] direction, 6.1% along the [200] direction) exhibits the best catalytic performance. This work may be beneficial for the design and surface engineering of catalysts toward specific applications.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Xian Li,Pingying Liu,Jumei Li
In this study, a facile and efficient approach was proposed for fabricating magnetically separable core-shell structured nanocomposites consisting of a magnetic Fe 3 O 4 core, a mesoporous ZrO 2 (mZrO 2 ) interlayer and an outer Ag nanoparticles shell using a sol-gel process and a wet chemistry method at ambient condition, and the hydrothermal treatment . The resulting Fe 3 O 4 /mZrO 2 /Ag nanocomposites were analyzed by TEM and SEM images, XPS , EDX and XRD spectra. Their photocatalytic activity was examined for the degradation of methylene blue under UV light . The effect of initial concentration, catalyst dosage and pH value was investigated and the results were discussed. Fe 3 O 4 /mZrO 2 /Ag nanocomposites showed higher photocatalytic activity, compared with Fe 3 O 4 /mZrO 2 composites. The PL analysis revealed Fe 3 O 4 /mZrO 2 composites possessed the enhanced separation efficiency of electron-hole pairs in comparison with Fe 3 O 4 /mZrO 2 . Moreover, the Fe 3 O 4 /mZrO 2 /Ag nanocomposites can be easily separated and recycled with an external magnetic field, and so they present remarkable reusability.
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
Materials
·
2024
·Vol. 17
·期 2
·509
·
IF 3.1
Shuya Ning,Shuo Wang,Zhihui Liu,Naming Zhang,Bin Yang,Fanghui Zhang
Magnetic–plasmonic nanoparticles (NPs) have attracted great interest in many fields because they can exhibit more physical and chemical properties than individual magnetic or plasmonic NPs. In this work, we synthesized Au- or Ag-decorated Fe3O4nanoparticles coated with PEI (Fe3O4-PEI-M (M = Au or Ag) NPs) using a simple method. The influences of the plasmonic metal NPs’ (Au or Ag) coating density on the magnetic and plasmonic properties of the Fe3O4-PEI-M (M = Au or Ag) NPs were investigated, and the density of the plasmonic metal NPs coated on the Fe3O4NPs surfaces could be adjusted by controlling the polyethyleneimine (PEI) concentration. It showed that the Fe3O4-PEI-M (M = Au or Ag) NPs exhibited both magnetic and plasmonic properties. When the PEI concentration increased from 5 to 35 mg/mL, the coating density of the Au or Ag NPs on the Fe3O4NPs surfaces increased, the corresponding magnetic intensity became weaker, and the plasmonic intensity was stronger. At the same time, the plasmonic resonance peak of the Fe3O4-PEI-M (M = Au or Ag) NPs was red shifted. Therefore, there was an optimal coverage of the plasmonic metal NPs on the Fe3O4NPs surfaces to balance the magnetic and plasmonic properties when the PEI concentration was between 15 and 25 mg/mL. This result can guide the application of the Fe3O4-M (M = Au or Ag) NPs in the biomedical field.
研究领域:
纳米材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2021
·
IF 3.927
Xiao Tian,Jiaxiong Xu
The reported Ag and Mn co-doped Cu 2 ZnSnS 4 thin film has better properties than single-doped Cu 2 ZnSnS 4 . However, the role of Mn in co-doped Cu 2 ZnSnS 4 thin film is still unclear. In this paper, Ag and Mn co-doped Cu 2 ZnSnS 4 thin films with different Mn amounts were prepared by sol-gel method. The crystal phases, morphologies, element compositions, and optical properties of co-doped Cu 2 ZnSnS 4 thin films were characterized to investigate the role of Mn doping. Compared with Ag single-doped Cu 2 ZnSnS 4 thin film, after the incorporation of Mn into Ag-doped Cu 2 ZnSnS 4 , the crystallinity of Cu 2 ZnSnS 4 improves and the micro-strain and dislocation density in the crystal reduce. The valence states of Cu, Zn, Sn, S, Ag, and Mn in co-doped thin film are +1, +2, +4, −2, +1, and +2, respectively. Mn doping can make the grains on the thin film surface enlarge. The MoS 2 interface layer between Cu 2 ZnSnS 4 and Mo becomes thinner and the Urbach energy of Cu 2 ZnSnS 4 decreases after Mn doping. Therefore, Mn in the co-doped Cu 2 ZnSnS 4 thin films shows beneficial effects of enhanced structural, morphological, and optical properties of the films.
研究领域:
材料科学
·
光伏技术
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2021
·
IF 4.098
Xuemin Xia,Yijin Weng,Lei Zhang,Ruyi Tang,Xia Zhang
Surface-Enhanced Raman Scattering (SERS) is a powerful analysis technology, attracting more and more attention due to its high sensitivity and selectivity. Herein, we report a simple seed-mediated method to synthesize Au@Ag nanoparticles (NPs) as a multifunctional biosensor for the label-free detection of hydrogen peroxide (H 2 O 2 ) and glucose by SERS. Au@Ag NPs, as an ultrasensitive SERS substrate, show the dual activities (peroxidase-like and GOx-like activities). Under the condition of pH 4.0 NaAc buffer solution, the glucose and H 2 O can be catalyzed by Au@Ag NPs to produce glucose acid and H 2 O 2 , and then H 2 O 2 can oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) to form a blue oxidation product oxidic TMB (oxTMB) which exhibits strong SERS signals at 1188, 1330, 1605 cm −1 . Thus, we have developed a new SERS strategy for analysis of glucose with a detection limit of 5 × 10 − 10 mol L −1 , suggesting that Au@Ag NPs have the potential for biosensor, immunoassay and medical treatment.
研究领域:
生物传感
·
医学检测
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Ye Zhang,Zhongyi Jiang,Jing Song,Jian Song,Fusheng Pan,Peng Zhang,Xingzhong Cao
Polymeric dense membranes for separating molecules with similar properties in liquid mixture according to solution-diffusion mechanisms are often constrained by trade-off effects. Integrating a facilitated transport mechanism and a sieving mechanism into membranes is a preferred approach to address this issue. Herein, amine-functionalized titanium-based metal–organic frameworks (NH2-MIL-125(Ti)) immobilized with Ag+, Ag+@NH2-MIL-125(Ti), was synthesized and hybrid membranes were fabricated for pervaporative desulfurization. The immobilized Ag+ can form reversible π-complexation toward thiophene and achieve thiophene-selectivity transport via a facilitated transport mechanism; meanwhile, Ag+ can decrease the effective pore size of the MOFs to elevate the diffusion selectivity of thiophene via a sieving mechanism. Accordingly, the resulting Pebax membranes with 1.0 wt % Ag+@NH2-MIL-125(Ti) exhibit a permeation flux of 22.11 kg/(m2 h) and an enrichment factor of 5.92. Furthermore, the hybrid membranes display increased thermostability and antiswelling properties by the incorporation of Ag+@NH2-MIL-125(Ti). This study proposes a strategy for the rational design of MOFs as nanofillers and endow the membranes with superior separation performance by integrating multiple transport mechanisms.
研究领域:
材料科学
·
分离技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2024
·
IF 2.7
Kang Shen,Caili Bi,Haifan Yang,Miaowen Xu,Lili Huang,Youwei Wang
Based on the coordination principle of Lewis acid, the 4-mercaptophenylboronic acid (4-MPBA)-modified novel dumbbell-shaped Au-Ag nanorods (4-MPBA@DS Au-AgNRs) substrate has been developed, which could be combined with the surface-enhanced Raman scattering (SERS) technique to detect SO42- with high sensitivity and specificity. DS Au-AgNRs synthesized in this paper with dumbbell particular structure have been verified by finite-difference time domain (FDTD) simulation to be capable of stimulating strong localized electromagnetic enhancement (EM) at nano-edge, gap, generating a large number of “hot spots” exhibiting excellent SERS performance. The 4-MPBA modified on its surface could specifically recognize SO42-, producing a change in the spectral peak at 1382 cm-1, thus realizing highly sensitive and specific sensing of SO42-. Under optimized conditions, this SERS sensor responded rapidly to SO42- within 2 minutes and demonstrated uncommon immunity. Ratio calculation by the ratio of the characteristic peaks at 1382 and 1070 cm-1 (I1382/I1070) enabled quantitative detection of SO42- in the range of 1 × 10-8-1 × 10-3 M, and the detection threshold was as low as 1 nM, which was superior to that of similar detection methods. Importantly, the utility and reliability of this SERS substrate for the determination of SO42- in actual samples were evaluated using ion chromatography as the gold standard, and there was no significant difference between the two protocols (P > 0.05), and the RSD was less than 6% with a satisfactory recovery rate (97.6-102.3%). Therefore, the present protocol has the advantages of simplicity and rapidity, high sensitivity, specificity, stability, and practicability in the determination of SO42- in aqueous solution, providing a reliable solution for tracing SO42- in the field of food safety and environmental testing.
研究领域:
分析化学
·
环境科学
·
食品安全
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS & DESIGN
·
2020
·
IF 6.289
Lizhu Guan,Ling Weng,Qiong Li,Xiaorui Zhang,Zijian Wu,Yingyi Ma
With a strong ability in tailoring molecular structure, nanoscale morphology, and nanodomains, the ferromagnetic metal-organic framework (MOF, M = transition metal) has been considered an advantageous candidate material for dielectric nanocomposites. Herein, a pristine content-controlled Ag nanoparticle driving Ni metal-organic framework (Ag-NiMOF) ultra-thin 2D ferroelectric nanoplatelets have been synthesized by a two-step method, and applied to the PVDF-based energy storage materials. Comprehensive tests and multi-physics simulations have been conducted on the electrical properties of materials. The electric displacement-electric field (D-E) hysteresis loops of the composites show that the discharge density of 6.987 J/cm 3 ~ 2300 kV/cm has been achieved with a 10 wt% filler addition, namely 10Ag-NiMOF/PVDF, which indicates a 5.36 times increase in the discharge density. Finite element simulation further verifies the improvement of the displacement and electrical breakdown strength of the composites. This high performance indicates that both of the centrosymmetric lattice nanodomains of NiMOF and the electrons introduced by Ag nanoparticle would help induce greater polarization in the nanocomposite. Furthermore, the Coulomb blockade effect exerted by the Ag nanoparticle with an appropriate particle size and a fractional concentration can significantly improve the electrical breakdown strength. This 2D hybrid particle provides a novel idea for modifying dielectric composites for high storage device applications.
研究领域:
材料科学
·
能源存储
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Ke Ye,Tianfu Liu,Yanpeng Song,Qi Wang,Guoxiong Wang
Electrochemical CO 2 reduction reaction (CO 2 RR) offers an appealing route to simultaneously store intermittent renewable energy as value-added chemicals and close carbon cycle. Silver (Ag) catalyst is a promising candidate for the electrochemical conversion of CO 2 to CO, but the electrocatalytic properties are still insufficient for practical applications. Herein, we put forward a strategy to in situ reconstruct a heterogeneous Ag 2 S/Ag interface structure, in which their strong interactions facilitate CO 2 RR performance. The in situ reconstructive Ag 2 S/Ag catalyst achieves a large current density of 421.7 ± 14.4 mA cm –2 at –0.70 V vs . reversible hydrogen electrode (RHE) and maintains steadily at a current density of 244.5 ± 31.8 mA cm –2 and CO Faradaic efficiency of 99.1 ± 0.8 % at –0.49 V vs . RHE for 50 h, superior to state-of-the-art CO-selective Ag-based catalysts. Density functional theory calculations reveal that the in situ reconstructive Ag 2 S/Ag interface active sites stabilize the *COOH intermediate during CO 2 RR process.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2019
·
IF 2.584
Lian Hu,Tianning Xu,Huaxin Zhu,Chaoqun Ma,Guoqing Chen
Enhanced luminescence of an emitter on a Ag film is usually ascribed to the resonant surface plasmons. In these studies, the solid cadmium sulfide (CdS) and cadmium selenide (CdSe) quantum dot/silver (QD/Ag) hybrids were prepared, and the luminescence characteristics of these QD/Ag hybrids were measured. It is found that the enhancement of the trap state emission (TSE) is related to the QD size. The TSE features of the annealed QD/Ag hybrids are insensitive to the morphology of the Ag film. We used the wet and dry methods to separate the QD and Ag components and found that the photoluminescence (PL) of the QD component was permanently changed from the initial state. The PL modification is ascribed to the Ag+ doping effect rather than the surface plasmons. This doping method uses pure Ag as the Ag+ ion source. In this case, though the CdS and CdSe QD/Ag hybrids are the solid state, the cation exchange between Ag+ and Cd2+ ions can still occur on the QD surface. Even a small amount of Ag can efficiently influence the luminescence of the QDs embedded in the poly(methyl methacrylate) matrix. A hypothetical model was proposed to explain the PL modification of the QD/Ag hybrid with and without annealing. Using this dry method for doping, the transparent luminescence label can be prepared easily, and the doped QDs can be further doped with Ag+ dopants.
研究领域:
材料科学
·
光学
✓ 已验证
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）