نتایج جستجو برای: Nitrogen and thiol-doped graphene quantum dots

تعداد نتایج: 16961753  

Journal: :Journal of the American Chemical Society 2012
Qiqi Li Sheng Zhang Liming Dai Liang-shi Li

Nitrogen doping has been a powerful way to modify the properties of carbon materials ranging from activated carbon to graphene. Here we report on a solution chemistry approach to nitrogen-doped colloidal graphene quantum dots with well-defined structures. N-doping was demonstrated to significantly affect the properties of the quantum dots, including the emergence of size-dependent electrocataly...

2014
L. A. Ponomarenko F. Schedin A. K. Geim S. P. Lau R. Bhardwaj S. J. Tang W. J. Yuan

Nitrogen-doped graphene quantum dots (N-GQDs) were fabricated by microwave-assisted hydrothermal technique. The optical properties of the N-GQDs were studied. The luminescence of the N-GQDs can be tuned by varying the excitation wavelength. Furthermore, two-photon luminescence of the N-GQDs excited by near-infrared laser can be obtained. It is shown that N-doping play a key role on two-photon l...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم پایه 1391

a simple, rapid and low-cost scanner spectroscopy method for the glucose determination by utilizing glucose oxidase and cdte/tga quantum dots as chromoionophore has been described. the detection was based on the combination of the glucose enzymatic reaction and the quenching effect of h2o2 on the cdte quantum dots (qds) photoluminescence.in this study glucose was determined by utilizing glucose...

At the present theoretical study, DFT calculations were performed for elucidating thereaction, absorption energy and the quantum molecular descriptors including electronic chemical potential, chemical hardness, Homo, Lumo, band gap energy (Eg) and finding the most active nitrogen-doped graphene sheet (N-G) for absorption H2S, CH4, N2 and CO2 gases. Finally it found that nitrogen-doped gra...

Journal: :Angewandte Chemie 2013
Yongqiang Dong Hongchang Pang Hong Bin Yang Chunxian Guo Jingwei Shao Yuwu Chi Chang Ming Li Ting Yu

Helpful elements: A facile bottom-up method using citric acid and L-cysteine as a precursor has been developed to prepare graphene quantum dots (GQDs) co-doped with nitrogen and sulfur. A new type and high density of surface state of GQDs arises, leading to high yields (more than 70 %) and excitation-independent emission. FLQY = fluorescence quantum yield.

2017
Xiaofen Xu Fuhua Gao Xiaohua Bai Fuchi Liu Wenjie Kong Ming Li

Nitrogen-doped graphene quantum dots (NGQDs) were synthesized by irradiating graphene quantum dots (GQDs) in an NH₃ atmosphere. The photoluminescence (PL) properties of the GQDs and the NGQDs samples were investigated. Compared with GQDs, a clear PL blue-shift of NGQDs could be achieved by regulating the irradiating time. The NGQDs obtained by irradiation of GQDs for 70 min had a high N content...

2016
Yuan Liu Yuting Shen Litao Sun Jincheng Li Chang Liu Wencai Ren Feng Li Libo Gao Jie Chen Fuchi Liu Yuanyuan Sun Nujiang Tang Hui-Ming Cheng Youwei Du

Doping of low-dimensional graphitic materials, including graphene, graphene quantum dots and single-wall carbon nanotubes with nitrogen, sulfur or boron can significantly change their properties. We report that simple fluorination followed by annealing in a dopant source can superdope low-dimensional graphitic materials with a high level of N, S or B. The superdoping results in the following do...

Fadavieslam, , Kazemi, , Yazdi, ,

In this work, the effect of doping Graphene Quantum Dots (GQDs) on their emission spectra has been studied. First, graphene has been deposited on SiC substrate by using sublimation method. Second, doped-GQDs have been distributed on the surface of graphene via drop casting. The structure of the samples have been studied and characterized by X-ray diffraction (XRD), Scanning Electron Microscopy ...

2016
Hanxu Ji Feng Zhou Jiangjiang Gu Chen Shu Kai Xi Xudong Jia

Nitrogen-doped carbon dots are introduced as a novel substrate suitable for enzyme immobilization in electrochemical detection metods. Nitrogen-doped carbon dots are easily synthesised from polyacrylamide in just one step. With the help of the amino group on chitosan, glucose oxidase is immobilized on nitrogen-doped carbon dots-modified carbon glassy electrodes by amino-carboxyl reactions. The ...

2014
S. Kumar G. S. Duesberg S. Raghavan R. Pratap

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