Self-Assembly of Helical Polyacetylene Nanostructures on Carbon Nanotubes

The self-assembling of helical polyacetylene (PA) nanostructures on single-walled nanotubes (SWNT) is studied using molecular dynamics (MD) simulations. The results indicate that SWNT can activate and guide the polymer chains helically wrapping onto it through van der Waals interaction and the π–π stacking interaction between the polymer chain and the outer surface of SWNT. The effects of SWNT diameter, SWNT chirality, and PA chain length on the configuration of the nanostructure have been extensively examined. It is found that a DNA-like double helix of two PA chains appears when the diameter of SWNT is larger than about 13.56 Å, the SWNT chirality has a negligible effect on whether the helical process could happen, and the two PA chains can interact with each other and then influence the formation of the perfect double helix. The geometrical structures between PA and SWNT may trigger enormous interests in chemical functionalization and helical polymer synthesis, which may eventually be beneficial for fabricating nanoscale devices. In addition, the self-assembly process of helical nanostructures on SWNT may also be helpful for understanding biological systems at the molecular level and for developing new materials

Adsorption and Catalytic Activation of O₂ Molecule on the Surface of Au-Doped Graphene under an External Electric Field

The interaction between oxygen molecule (O₂) and metal-doped graphene has always been a heated discussed issue because O₂ plays an important role in the graphene-based gas-storage materials, sensing platforms, and catalysts. In this article, the effect of an external electric field on the interaction between O₂ and Au-doped graphene is studied using density-functional theory (DFT) calculations. The simulations show that O₂ vertically moves away from Au-doped graphene substrate under a positive electric field, whereas under a negative electric field, accompanied by the vertical pushing out movement, O₂ also moves toward the specific Au atom horizontally. Besides, the adsorption energy (<i>E</i>_ad) of O₂ is dramatically changed with electric field. A negative electric field strengthens the interaction between O₂ and Au-doped graphene substrate, resulting in an enhanced <i>E</i>_ad; the corresponding O–O distance (<i>d</i>_O–O) is also elongated, while <i>E</i>_ad is decreased and <i>d</i>_O–O is shortened under a positive electric field. Because <i>d</i>_O–O of the adsorbed O₂ correlates with its catalytic activation, the findings can provide a new avenue to tune the O₂ adsorption process onto Au-doped graphene substrate and may be useful in the future applications of graphene-based nanocatalyst

Additional file 1: of Insights into the H2/CH4 Separation Through Two-Dimensional Graphene Channels: Influence of Edge Functionalization

Supporting information. Fig. S1. Final configurations of the 1:1 H2/CH4 mixture permeating through the 2D channel of pristine and edge-functionalized GMs (DOCX 4515 kb

Hyper-Branched Cu@Cu₂O Coaxial Nanowires Mesh Electrode for Ultra-Sensitive Glucose Detection.

Electrode design in nanoscale is expected to contribute significantly in constructing an enhanced electrochemical platform for a superb sensor. In this work, we present a facile synthesis of new fashioned heteronanostructure that is composed of one-dimensional Cu nanowires (NWs) and epitaxially grown two-dimensional Cu₂O nanosheets (NSs). This hierarchical architecture is quite attractive in molecules detection for three unique characteristics: (1) the three-dimensional hierarchical architecture provides large specific surface areas for more active catalytic sites and easy accessibility for the target molecules; (2) the high-quality heterojunction with minimal lattice mismatch between the built-in current collector (Cu core) and active medium (Cu₂O shell) considerably promotes the electron transport; (3) the adequate free space between branches and anisotropic NWs can accommodate a large volume change to avoid collapse or distortion during the reduplicative operation processes under applied potentials. The above three proposed advantages have been addressed in the fabricated Cu@Cu₂O NS-NW-based superb glucose sensors, where a successful integration of ultrahigh sensitivity (1420 μA mM^–1 cm^–2), low limit of detection (40 nM), and fast response (within 0.1 s) has been realized. Furthermore, the durability and reproducibility of such devices made by branched core–shell nanowires were investigated to prove viability of the proposed structures. This achievement in current work demonstrates an innovative strategy for nanoscale electrode design and application in molecular detection

Quantitative Time-Resolved Visualization of Catalytic Degradation Reactions of Environmental Pollutants by Integrating Single-Drop Microextraction and Fluorescence Sensing

Current methods for evaluating catalytic degradation reactions of environmental pollutants primarily rely on chromatography that often suffers from intermittent analysis, a long turnaround period, and complex sample pretreatment. Herein, we propose a quantitative time-resolved visualization method to evaluate the progress of catalytic degradation reactions by integrating sample pretreatment [single-drop microextraction, (SDME)], fluorescence sensing, and a smartphone detection platform. The dechlorination reaction of chlorobenzene derivatives was first investigated to validate the feasibility of this approach, in which SDME plays a critical role in direct sample pretreatment, and inorganic CsPbBr3 perovskite encapsulated in a metal–organic framework (MOF-5) was utilized as the fluorescent chromogenic agent (FLCA) in SDME to realize fast in situ colorimetric detection via the color switching from green (CsPbBr3) to blue (chlorine lead bromide, inorganic CsPbCl3 perovskite). The smartphone, which can calculate the B/G value of FLCA, serves as a data output window for quantitative time-resolved visualization. Further, a [Eu(PMA)]n (PMA= pyromellitic acid) fluorescent probe was constructed to use as an FLCA for the in situ evaluation of cinnamaldehyde and p-nitrophenol catalytic reduction. This approach not only minimizes the utilization of organic solvents and achieves quantitively efficient time-resolved visualization but also provides a feasible method for in situ monitoring of the progress of catalytic degradation reactions

Quantitative Time-Resolved Visualization of Catalytic Degradation Reactions of Environmental Pollutants by Integrating Single-Drop Microextraction and Fluorescence Sensing

Current methods for evaluating catalytic degradation reactions of environmental pollutants primarily rely on chromatography that often suffers from intermittent analysis, a long turnaround period, and complex sample pretreatment. Herein, we propose a quantitative time-resolved visualization method to evaluate the progress of catalytic degradation reactions by integrating sample pretreatment [single-drop microextraction, (SDME)], fluorescence sensing, and a smartphone detection platform. The dechlorination reaction of chlorobenzene derivatives was first investigated to validate the feasibility of this approach, in which SDME plays a critical role in direct sample pretreatment, and inorganic CsPbBr3 perovskite encapsulated in a metal–organic framework (MOF-5) was utilized as the fluorescent chromogenic agent (FLCA) in SDME to realize fast in situ colorimetric detection via the color switching from green (CsPbBr3) to blue (chlorine lead bromide, inorganic CsPbCl3 perovskite). The smartphone, which can calculate the B/G value of FLCA, serves as a data output window for quantitative time-resolved visualization. Further, a [Eu(PMA)]n (PMA= pyromellitic acid) fluorescent probe was constructed to use as an FLCA for the in situ evaluation of cinnamaldehyde and p-nitrophenol catalytic reduction. This approach not only minimizes the utilization of organic solvents and achieves quantitively efficient time-resolved visualization but also provides a feasible method for in situ monitoring of the progress of catalytic degradation reactions

Zeolite Y Mother Liquor Modified γ‑Al₂O₃ with Enhanced Brönsted Acidity as Active Matrix to Improve the Performance of Fluid Catalytic Cracking Catalyst

A new matrix material for the fluid catalytic cracking (FCC) catalyst was prepared using the zeolite Y mother liquor to modify the surface acidity of γ-Al₂O₃. The modified γ-Al₂O₃ was characterized using a variety of techniques, and the relationship between surface acidity and catalytic performances in the catalytic cracking of vacuum gas oil (VGO) was correlated. Characterization results showed that Brönsted acid sites derived mainly from isolated silanol groups, which increased on modified γ-Al₂O₃, while Lewis acid sites reduced dramatically after modification. Correlation results indicated that increased Brönsted acid sites effectively improved the conversion of VGO. In addition, new medium strong acid sites engendered at the interfaces of γ-Al₂O₃/amorphous silica–alumina or γ-Al₂O₃/zeolite Y played a critical role in determining the final product distribution, leading to yields of gasoline and liquefied petroleum gas higher than those of the pure γ-Al₂O₃ derived catalyst

Quantitative Time-Resolved Visualization of Catalytic Degradation Reactions of Environmental Pollutants by Integrating Single-Drop Microextraction and Fluorescence Sensing

Current methods for evaluating catalytic degradation reactions of environmental pollutants primarily rely on chromatography that often suffers from intermittent analysis, a long turnaround period, and complex sample pretreatment. Herein, we propose a quantitative time-resolved visualization method to evaluate the progress of catalytic degradation reactions by integrating sample pretreatment [single-drop microextraction, (SDME)], fluorescence sensing, and a smartphone detection platform. The dechlorination reaction of chlorobenzene derivatives was first investigated to validate the feasibility of this approach, in which SDME plays a critical role in direct sample pretreatment, and inorganic CsPbBr3 perovskite encapsulated in a metal–organic framework (MOF-5) was utilized as the fluorescent chromogenic agent (FLCA) in SDME to realize fast in situ colorimetric detection via the color switching from green (CsPbBr3) to blue (chlorine lead bromide, inorganic CsPbCl3 perovskite). The smartphone, which can calculate the B/G value of FLCA, serves as a data output window for quantitative time-resolved visualization. Further, a [Eu(PMA)]n (PMA= pyromellitic acid) fluorescent probe was constructed to use as an FLCA for the in situ evaluation of cinnamaldehyde and p-nitrophenol catalytic reduction. This approach not only minimizes the utilization of organic solvents and achieves quantitively efficient time-resolved visualization but also provides a feasible method for in situ monitoring of the progress of catalytic degradation reactions

Quantitative Time-Resolved Visualization of Catalytic Degradation Reactions of Environmental Pollutants by Integrating Single-Drop Microextraction and Fluorescence Sensing

Current methods for evaluating catalytic degradation reactions of environmental pollutants primarily rely on chromatography that often suffers from intermittent analysis, a long turnaround period, and complex sample pretreatment. Herein, we propose a quantitative time-resolved visualization method to evaluate the progress of catalytic degradation reactions by integrating sample pretreatment [single-drop microextraction, (SDME)], fluorescence sensing, and a smartphone detection platform. The dechlorination reaction of chlorobenzene derivatives was first investigated to validate the feasibility of this approach, in which SDME plays a critical role in direct sample pretreatment, and inorganic CsPbBr3 perovskite encapsulated in a metal–organic framework (MOF-5) was utilized as the fluorescent chromogenic agent (FLCA) in SDME to realize fast in situ colorimetric detection via the color switching from green (CsPbBr3) to blue (chlorine lead bromide, inorganic CsPbCl3 perovskite). The smartphone, which can calculate the B/G value of FLCA, serves as a data output window for quantitative time-resolved visualization. Further, a [Eu(PMA)]n (PMA= pyromellitic acid) fluorescent probe was constructed to use as an FLCA for the in situ evaluation of cinnamaldehyde and p-nitrophenol catalytic reduction. This approach not only minimizes the utilization of organic solvents and achieves quantitively efficient time-resolved visualization but also provides a feasible method for in situ monitoring of the progress of catalytic degradation reactions

Quantitative Time-Resolved Visualization of Catalytic Degradation Reactions of Environmental Pollutants by Integrating Single-Drop Microextraction and Fluorescence Sensing

Current methods for evaluating catalytic degradation reactions of environmental pollutants primarily rely on chromatography that often suffers from intermittent analysis, a long turnaround period, and complex sample pretreatment. Herein, we propose a quantitative time-resolved visualization method to evaluate the progress of catalytic degradation reactions by integrating sample pretreatment [single-drop microextraction, (SDME)], fluorescence sensing, and a smartphone detection platform. The dechlorination reaction of chlorobenzene derivatives was first investigated to validate the feasibility of this approach, in which SDME plays a critical role in direct sample pretreatment, and inorganic CsPbBr3 perovskite encapsulated in a metal–organic framework (MOF-5) was utilized as the fluorescent chromogenic agent (FLCA) in SDME to realize fast in situ colorimetric detection via the color switching from green (CsPbBr3) to blue (chlorine lead bromide, inorganic CsPbCl3 perovskite). The smartphone, which can calculate the B/G value of FLCA, serves as a data output window for quantitative time-resolved visualization. Further, a [Eu(PMA)]n (PMA= pyromellitic acid) fluorescent probe was constructed to use as an FLCA for the in situ evaluation of cinnamaldehyde and p-nitrophenol catalytic reduction. This approach not only minimizes the utilization of organic solvents and achieves quantitively efficient time-resolved visualization but also provides a feasible method for in situ monitoring of the progress of catalytic degradation reactions