Related Experiment Video
Updated: Jul 31, 2026

Compact Quantum Dots for Single-molecule Imaging
Published on: October 9, 2012
Microwave-assisted synthesis of amphoteric fluorescence carbon quantum dots and their chromium adsorption from
Hebat-Allah S Tohamy1, Mohamed El-Sakhawy2, Samir Kamel1
1Cellulose and Paper Department, National Research Centre, 33 El Bohouth Str., P.O. 12622, Dokki, Giza, Egypt.
Abstract:
The chromium adsorption behavior from aqueous solution by the amphoteric Janus nitrogen-doped carbon quantum dots (AJ-N-CQDs) was investigated. The pseudo-first-order and the second-order adsorption kinetics models were employed to analyze the experimental data; the second-order adsorption kinetics model presented a better correlation to the experimental data, suggesting a chemisorptions process. The values obtained in the pseudo-first-order are still suitable for describing the Kinetics of Cr(VI) sorption. These values elucidate the surface processes involving chemisorption and physisorption in the adsorption of Cr(VI) by AJ-N-CQDs. The R2 of the Boyd model gave a better fit to the adsorption data of AJ-N-CQDs (i.e., external diffusion), which means the surface processes involving external Cr(VI) adsorption by AJ-N-CQDs. The higher value of α may be due to the greater surface area of the AJ-N-CQDs for the immediate adsorption of Cr(VI) from the aqueous solution. AJ-N-CQDs have fluorescence spectra before and after Cr(VI) adsorption, indicating they are promising for chemical sensor applications.
More Related Videos
Related Concept Videos
Mass Spectrometry: Overview
Mass Spectrum
Chemical Ionization (CI) Mass Spectrometry
¹³C NMR: ¹H–¹³C Decoupling
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
Mass Spectrometry: Isotope Effect
Mass Spectrum: Interpretation

