Multicolor tuning is one of the most remarkable features of carbon dots (CDs), used as a color convertor in making white-light-emitting diodes (WLEDs). Herein, a solvent-controlled method has been employed to prepare the multicolor-emissive CDs from 1,2,4-triaminobenzene and melamine, where the green-, orange-, and red-color-emissive carbon dots (G-, O-, and R-CDs) have been synthesized in acetone, water, and dimethylformamide (DMF), respectively. It has noted that the reaction solvent has impacted the growth of the particle size, elemental concentration, surface functionalization, and ultimately fluorescence emission. To avoid aggregation quenching emission (AQE), fluorescent polymeric films have been shaped by mixing poly(methyl methacrylate) (PMMA) with R-and G-CDs, while O-CDs was made with poly(vinyl alcohol) (PVA). Interestingly, PVA exhibited red-shifted emission of O-CDs from 585 to 597 nm in O-CDs/ PVA, while PMMA accompanied a blue-shifting emission. The enriched nitrogen and oxygen elemental contents, especially the graphitic N of O-CDs/PVA, and hydrogen-bonding affinity of PVA cause the red-shifted emission of O-CDs/PVA. Fluorescent solid films have been used to develop monochromatic and white-color-emissive light-emitting diodes. Further, all of the synthesized CDs served as carbon precursors to develop room-temperature phosphorescence (RTP) by a molten salt method, where only R-and O-CDs achieved their RTP emissions with different intensities. The mechanism behind the RTP formation with particular CDs and their emission intensity dependency has been studied by the C�O moieties.
Anthraquinone dyes are one of the major water pollutants due to their stability and persistence in the aquatic system. The present study describes the use of activated charcoal prepared from Thuja orientalis leaves (ACTOL) as an adsorbent to remove reactive anthraquinone dye Remazol Brilliant Blue R (RBBR) from its aqueous solution. In this work, leaves of the plant were carbonated to get fine charcoal which was activated by acid treatment and analysed by BET, SEM and FTIR techniques. Batch experiments were conducted to study the effect of pH, contact time, concentration and amount of adsorbent on the removal of RBBR in the concentration range 0.1-6.65 m mol L −1 . The highest efficiency was found to be 81% at pH 6 and contact time of 300 min. Adsorption data were analysed by Langmuir, Freundlich and Temkin isotherm models. The adsorption was found to follow Freundlich adsorption isotherm (R 2 = 0.9972). The kinetic study of the process was done by analysing the time adsorption data with pseudo-first-order, pseudo-second-order and intraparticle diffusion models, and it was found to obey pseudo-second-order kinetics. The adsorbent showed 73% of efficiency even after four regeneration cycles. FTIR analysis revealed that the various groups present at the surface of adsorbent were responsible for uptake of dye molecules. This study reveals that leaves of Thuja orientalis, a common biowaste, can be used as an efficient adsorbent for the removal of RBBR dye from its aqueous solution. It provides an economical and eco-friendly way to mitigate the waste and use it as an adsorbent.
Red-color emitting carbon dots (CDs) are of tremendous interest in the field of materials discipline because of their promising applications in the domains of forensic applications, lighting, fingerprinting, imaging, sensing,...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.