Fluorescent carbon nanoparticles from Citrus sinensis as efficient sorbents for pollutant dyes

Abstract

Here, we report a simple, green and economic process for the synthesis of highly fluorescent carbon nanoparticles (CPs) through low-temperature carbonization of a fruit waste, Citrus sinensis peel. This approach allows the large-scale production of aqueous CPs dispersions without any additives and post-treatment processes. The as-prepared CPs were of small particle size, exhibited bright blue fluorescence under UV irradiation (λ = 365 nm) with excellent colloidal stability in water. The chemical composition, structure and morphology of the as-prepared CPs were analyzed using various spectroscopic techniques such as X-ray diffraction, transmission electron microscopy and raman spectroscopy. The formed CPs were turbostratic in nature, with a large number of functional groups on the surface. We explored the adsorption characteristics of the formed CPs for wastewater treatment. Because of the negative surface of the CPs, as evident from the zeta value, it is possible to use them for selective adsorption of the cationic dye methylene blue from a mixture of dyes. The equilibrium adsorption isotherm revealed that the Langmuir model better describes the adsorption process than the Freundlich model. As-prepared CPs rapidly adsorbed ~84% of the methylene blue within 1 min and can be regenerated and used repeatedly. Copyright © 2016 John Wiley & Sons, Ltd.

Preparation of carbon dot‐based ratiometric fluorescent probes for cellular imaging from Curcuma longa

“…Furthermore, TEM revealed the morphology of all FNP types, which display as dot shapes with an average diameter of 4 to 20 nm and have a dark surface color, demonstrating successful surface passivation. The lattice separation of the materials (approximately 0.290 to 0.308 nm) confirmed the graphene carbon structures indicating internalized carbon particles (Figure c and d) . The prepared CDs derived from natural sources have tunable absorption and fluorescence emission patterns, indicating the promising possibility for sustainability in bio‐probe applications.…”

“…The C-FNPs and P- (Figure 3c and d). [25][26][27][28] The prepared CDs derived from natural sources have tunable absorption and fluorescence emission patterns, indicating the promising possibility for sustainability in bio-probe applications.…”

Simple and eco‐friendly synthesis of crude orange‐peel‐derived carbon nanoparticles for detection of Fe3+ and ascorbic acid

“…Previous studies have shown that CDs derived from orange peels emitted blue fluorescence. [ 5–8,10,11 ] However, CPs obtained in this study emitted green/yellow fluorescence when ddH 2 O only was used as reaction solvent (Figure 1a). These inconsistent results might be due to different composition of the peels obtained from various oranges cultivars.…”

Carbon Dots: A Mystic Star in the World of Nanoscience

“…Step 2: surface modification (Figure 10(a)). The PL maximum for CDs commonly appears in the blue and green region of the spectra (Figure 10(b)) [41]. PL behavior of CDs can be controlled by varying the initial precursors and synthetic methodologies and by surface engineering [42].…”

“…(a) PL spectra of CDs with variation of excitation wavelengths (λ ex ); (b) excitation and PL emission spectra of CDs in the blue-green region (reproduced with permission from[41]). …”