The present study aims to compare the early stages of graphitization of the same DND source for two annealing atmospheres (primary vacuum, argon at atmospheric pressure) in an identical set-up. DND samples are finely characterized by a combination of complementary techniques (FTIR, Raman, XPS, HR-TEM) to highlight the induced modifications for temperature up to 1100 °C. The annealing atmosphere has a significant impact on the graphitization kinetics with a higher fraction of sp-C formed under vacuum compared to argon for the same temperature. Whatever the annealing atmosphere, carbon hydrogen bonds are created at the DND surface during annealing according to FTIR. A "nano effect", specific to the <10 nm size of DND, exalts the extreme surface chemistry in XPS analysis. According to HR-TEM images, the graphitization is limited to the first outer shell even for DND annealed at 1100 °C under vacuum.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8537936 | PMC |
| http://dx.doi.org/10.3390/nano11102671 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Numerical simulation of the heating process in a vacuum sintering electric furnace and structural optimization.
Sci Rep
December 2024
School of Energy Science and Engineering, Central South University, Changsha, 410083, China.
A three-dimensional numerical model of the vacuum sintering furnace was established, combined with the custom program of temperature-voltage feedback regulation. Through simulationand experimental validation, the heating and holding stage as well as the thermal hysteresis phenomenon of the furnace were analyzed, a dimensionless quantity of hysteresis temperature difference was proposed and calculated, the distribution of the electric field and temperature uniformity of the furnace were discussed in detail, while the structural improvement approach was proposed based on simulation. The results show that: during the heating process, the maximum of thermal hysteresis temperature difference between the graphite cylinder and the heating tube is 0.
View Article and Find Full Text PDFHumic acid promotes pathway of chloronitrobenzene cathodic reduction shunting from atomic H* to direct electron transfer.
Water Res
December 2024
College of Environment, Zhejiang University of Technology, No. 18 Chaowang Road, Hangzhou 310014, China; Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, Hangzhou 310014, China. Electronic address:
Progress mechanism of humic acid (HA) interacting with chloronitrobenzenes (ClNBs) and affecting their reduction and degradation was investigated. A two-stage chamber with graphite felt as cathode and anode was constructed, and 2,4-dichloronitrobenzene (2,4-DCNB) was target pollutant. Result showed that HA increased 36.
View Article and Find Full Text PDFCoal gangue-supported catalyst for the efficient conversion of waste plastics into hydrogen and carbon nanotubes.
J Environ Manage
December 2024
MOE Key Laboratory of Thermo-Fluid Science and Engineering, Xi'an Jiaotong University, Xi'an, Shanxi, 710049, China. Electronic address:
From an economic and environmental perspective, pyrolysis-catalysis is a promising method for converting waste plastics into high-value products. Low-cost catalysts are crucial for the large-scale processing of waste plastics. This study prepared a nickel-based catalyst supported on solid waste coal gangue (CG) using a simple impregnation method and investigated the effect of catalyst composition on the catalytic pyrolysis of polyethylene to produce hydrogen and high-value carbon nanotubes (CNTs).
View Article and Find Full Text PDFNonlinear optics of graphitic carbon allotropes: from 0D to 3D.
Nanoscale
December 2024
MOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai Frontiers Science Center of Digital Optics, Institute of Precision Optical Engineering, and School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China.
The dimensionality of materials fundamentally influences their electronic and optical properties, presenting a complex interplay with nonlinear optical (NLO) characteristics that remains largely unexplored. In this review, we focus on the influence of dimensionality on the NLO properties of graphitic allotropes, ranging from 0D fullerenes, 1D carbon nanotubes, and 2D graphene, to 3D graphite, all of which share a consistent sp hybridized chemical bonding structure. We examine the distinct physical and NLO properties across these dimensions, underscoring the profound impact of dimensionality.
View Article and Find Full Text PDFPractical considerations of promising zone design for interim sample size Re-estimation: An application to GRAPHITE for graft vs host disease.
Contemp Clin Trials
November 2024
Takeda Development Center Americas, Inc., Cambridge, MA, USA.
Background: Sample size calculation and power estimate are an integral part of clinical trials. With accelerated development to address the unmet medical needs, the fast-paced development may lead to uncertainties in initial planning and assumptions of clinical trials. Promising zone design presents sponsors an opportunity to re-estimate the sample size based on the interim data to mitigate risks, reduce uncertainties, and increase probability of trial success.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!