Facile Synthesis of Nitrogen-Doped Carbon Dots from Lignocellulosic Waste (original) (raw)
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Nanomaterials, 2022
Renewable biowaste-derived carbon dots have garnered immense interest owing to their exceptional optical, fluorescence, chemical, and environmentally friendly attributes, which have been exploited for the detection of metals, non-metals, and organics in the environment. In the present study, water-soluble fluorescent carbon dots (CDs) were synthesized via facile green microwave pyrolysis of pine-cone biomass as precursors, without any chemical additives. The synthesized fluorescent pine-cone carbon dots (PC-CDs) were spherical in shape with a bimodal particle-size distribution (average diameters of 15.2 nm and 42.1 nm) and a broad absorption band of between 280 and 350 nm, attributed to a π-π* and n-π* transition. The synthesized PC-CDs exhibited the highest fluorescent (FL) intensity at an excitation wavelength of 360 nm, with maximum emission of 430 nm. The synthesized PC-CDs were an excellent fluorescent probe for the selective detection of Cu2+ in aqueous solution, amidst the pr...
Journal of Nanostructures, 2020
In this experimental work, nitrogen-doped carbon quantum dots were successfully synthesized with hydrothermal of the milk. The product was composed of a powder and a stable colloid. The structure of the product was examined by XRD, EDS and FT-IR analysis. Also the particle size of the product was investigated by SEM and TEM images and the results showed the product is mainly composed of the particles with less than 5 nm in diameter. The photoluminescence intensity of the product was obtained by PL analysis and it was found the product has high photoluminescence intensity that can be improved by surface modification with N-Methyl-2-pyrrolidone. Due to high photoluminescence intensity of the obtained quantum dots they were used as sensor to detection of Cu2+ and it was observed they can detect this ion in the aqueous medium for 0-80 uM concentration range. Also it was found by surface modification of carbon dots with N-Methyl-2-pyrrolidone, the detection sensitivity is improved. The o...
Journal of the Turkish Chemical Society Section A: Chemistry, 2020
The search for nanoparticle metal chelator biomarker has been on the rise in recent years. In this study, bis(salicylidene)ethylenediamine (SALEN) functionalized carbon dot derived from waste banana peels was synthesized using facile hydrothermal technique and the optical biomarker and adsorption properties of the highly fluorescent red nanomaterial was studied. The carbon dot and its functionalized counterpart were characterized using FTIR, SEM/EDX, and UV-Visible spectrophotometry. Evaluation of the optical properties of the yellowish brown carbon dot and reddish highly luminescent functionalized carbon dot indicated band gap energy values of 1.85 and 2.04 eV, respectively. Extraneous variables such as effect of initial metal ion concentration, pH, and contact time were studied in the batch extraction process for the sorption of Cd(II) ions from aqueous solution. The sorption of Cd(II) ion was observed to be highest at pH 5 with 99.3 % removal efficiency. The adsorption isotherm and kinetic models indicated interplay of physisorption and chemisorption processes. The mechanism for the chelation of Cd(II) ions onto the surface of the functionalized carbon dot was mainly governed by inner sphere chelation and ion exchange. Reusability of the material was evaluated using adsorption-desorption experiments. Results of the study indicated the potential of the functionalized carbon dot as (i) semiconductor materials with strong photoluminescence at the visible region which could be used as environmental biomarker and as sensor, and (ii) effective, efficient and low cost adsorbent for remediating Cd(II) ions contaminated environment.
JOURNAL OF TURKISH CHEMICAL SOCIETY, SECTION A, 2021
The search for nanoparticle metal chelator biomarker has been on the rise in recent years. In this study, bis(salicylidene)ethylenediamine (SALEN) functionalized carbon dot derived from waste banana peels was synthesized using facile hydrothermal technique and the optical biomarker and adsorption properties of the highly fluorescent red nanomaterial was studied. The carbon dot and its functionalized counterpart were characterized using FTIR, SEM/EDX, and UV-Visible spectrophotometry. Evaluation of the optical properties of the yellowish brown carbon dot and reddish highly luminescent functionalized carbon dot indicated band gap energy values of 1.85 and 2.04 eV, respectively. Extraneous variables such as effect of initial metal ion concentration, pH, and contact time were studied in the batch extraction process for the sorption of Cd(II) ions from aqueous solution. The sorption of Cd(II) ion was observed to be highest at pH 5 with 99.3 % removal efficiency. The adsorption isotherm and kinetic models indicated interplay of physisorption and chemisorption processes. The mechanism for the chelation of Cd(II) ions onto the surface of the functionalized carbon dot was mainly governed by inner sphere chelation and ion exchange. Reusability of the material was evaluated using adsorption-desorption experiments. Results of the study indicated the potential of the functionalized carbon dot as (i) semiconductor materials with strong photoluminescence at the visible region which could be used as environmental biomarker and as sensor, and (ii) effective, efficient and low cost adsorbent for remediating Cd(II) ions contaminated environment.
Analytical Sciences, 2017
Presented here is a simple yet rapid and efficient analytical method for visual as well as spectroscopic method for sensing of trace concentrations of Cu 2+ ions in aqueous medium by systematic photoluminescence quenching of a highly water soluble probe made of CdS quantum dots surface modified by thiourea. The salient features of this work describe rapid detection (2 min equilibration time) of Cu 2+ ions at wider linear concentration range (0.025-10 mg/L) corresponding to a sensitivity of 2.81(mg/L)-1 and limit of quantification of 47.3 μg/L, respectively, suitable for Cu 2+ sensing in drinking water and ground water. Further, the detection of Cu 2+ ion was free from most interfering cations and anions, except for minor interference from Cr 3+ , Hg 2+ and Pb 2+. The robustness of our probe for Cu 2+ sensing is demonstrated from efficient Cu 2+ spike recovery analysis in groundwater and river water samples.
Analytical Sciences, 2017
Presented here is a simple yet rapid and efficient analytical method for visual as well as spectroscopic method for sensing of trace concentrations of Cu 2+ ions in aqueous medium by systematic photoluminescence quenching of a highly water soluble probe made of CdS quantum dots surface modified by thiourea. The salient features of this work describe rapid detection (2 min equilibration time) of Cu 2+ ions at wider linear concentration range (0.025-10 mg/L) corresponding to a sensitivity of 2.81(mg/L)-1 and limit of quantification of 47.3 μg/L, respectively, suitable for Cu 2+ sensing in drinking water and ground water. Further, the detection of Cu 2+ ion was free from most interfering cations and anions, except for minor interference from Cr 3+ , Hg 2+ and Pb 2+. The robustness of our probe for Cu 2+ sensing is demonstrated from efficient Cu 2+ spike recovery analysis in groundwater and river water samples.
Bio-Derived Fluorescent Carbon Dots: Synthesis, Properties and Applications
Molecules
The transformation of biowaste into products with added value offers a lucrative role in nation-building. The current work describes the synthesis of highly water-soluble, luminous carbon quantum dots (CQDs) in the size range of 5–10 nm from discarded rice straw. The small spherical CQDs that were formed had outstanding optical and luminescent qualities as well as good photostabilities. By performing quantitative multi-assay tests that included antioxidant activities, in vitro stability and colloidal assay investigations as a function of different CQD concentrations, the biocompatibility of CQDs was evaluated. To clearly visualize the type of surface defects and emissive states in produced CQDs, excitation-dependent fluorescence emission experiments have also been carried out. The “waste-to-wealth” strategy that has been devised is a successful step toward the quick and accurate detection of Cu2+ ion in aqueous conditions. The fluorescence-quenching behavior has specified the concen...
Multiresponsive water-stable luminescent Cd coordination polymer for detection of TNP and Cu2+
Sensors and Actuators B: Chemical, 2018
Amultiresponsive water-stable luminescent sensor was designed and synthesized. The sensor exhibited highly sensitive and selective detection of TNP in both DMF and aqueous media. A simple and reliable TNP detection method was developed. The sensor could selectively detect Cu2+ with a very large quenching coefficient. The quenching mechanisms were preliminarily studied.