Hydrothermal Synthesis of Fluorescent Schiff Base Functionalized Carbon Dot Composite for The Removal Of Cd(II) Ions From Aqueous Solution: Equilibrium and Kinetic Studies.

Abstract

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 studied. The carbon dot and its functionalized counterpart were characterized using FTIR, SEM/EDX and UV-Visible technique. 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 aphere chelation and ion exchange. Reusability of the material was evaluated using adsorption-desorption experiments. Result 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 (ii) effective, efficient and low cost adsorbent for remediating Cd(II) ions contaminated environment.

Keywords

• adsorption studies
• carbon dot nanoparticle
• cadmium
• adsorption mechanism
• desorption

References

1. 1. Musa YP, Zurina Z A, Suraya A R, Faizah M , Noor A S M, Mohammed A I. Eco-Friendly Sustainable Fluorescent Carbon Dots for the Adsorption of Heavy Metal Ions in Aqueous Environment. Nanomaterials.2019; 10:315.
2. 2. Waalkes M P (2000) Cadmium carcinogenesis in review. J. Inorg. Biochem. 2000; 79(1–4): 241–244. 3. Scimeca M, Feola M, Romano L, Rao C, Gasbarra E, Bonanno E. Heavy metals accumulation affects bone microarchitecture in osteoporoticpatients. Environ Toxicol. 2017; 32:1333-42.
3. 4. Ghorbani M, Eisazadeh H. Removal of COD, color,anions and heavy metals from cotton textile waste water by using polyaniline and polypyrrole nanocomposites coated on rice husk ash. Composites B: Eng.2015; 45(1): 1–7.
4. 5. Banerjee S, Chattopadyaya MC. Adsorption characteristics for the removal of a toxic dye, tartrazine from aqueous solutions by a low cost agricultural by-product. Arabian Journal of Chemistry.2017; 10:S1629-S1638.
5. 6. Moyakhe D, Waanders F.B, Le Roux M, Campbell M.Q. The Journal of the Southern African Institute of Mining and Metallurgy. 2019 ; 119 : 607-612.
6. 7. Khan A S, Dhevagi, P, Chitdeshwari P, Avudainayagam S (2018) Bio-sorption of cadmium from Aqeous solutions by banana peel powder. Madras Agric Journal.2018; 105(1- 3): 24-29.
7. 8. Abdolali A, Ngo HH, Guo W, Lu S, Chen SS, Nguyen NC, Zhang X, Wang J, Wu Y.A breakthrough biosorbents in removing heavy metals: equilibrium, kinetic, thermodynamic and mechanism analyses in a lab-scale study. Sci Total Environ.2016;542:603–611. 9. Tao S, Lu S, Geng Y, Zhu S, Redfern SAT, Song Y, Feng T, Xu W, Yang B. Design of metal-free polymer carbon dots: a new class of room-temperature phosphorescent materials Angew. Chem. Int. Ed. 2018; 57: 2393–2398.
8. 10. Kong W.Quantitative and real-time effects of carbon quantum dots on single living HeLa cell membrane permeability. Nanoscale.2014; 6: 5116–5120.

9. 11. Chen Y, Zheng M, Xiao Y, Dong H, Zhang H, Zhuang J, Hu H, Lei B, Liu Y. (2016). A self-quenching-resistant carbon-dot powder with tuneable solid-state fluorescence and construction of dual-fluorescence morphologies for white light-emission. Adv. Mater.2016; 28: 312–318. 12. Hu S. Tunable photoluminescence across the entire visible spectrum from carbon dots excited by white light. Angew. Chem. Int. Ed.2015; 54: 2970–2974.
10. 13. Ge J. Red-emissive carbon dots for fluorescent, photoacoustic, and thermal theranostics in living mice. Adv. Mater.2015; 27: 4169–4177.
11. 14. Young AT. Neuro-nano interfaces: utilizing nano-coatings and nanoparticles to enable next-generation electrophysiological recording, neural stimulation, and biochemi-cal modulation. Adv. Funct. Mater. 2018; 28: 1700239.
12. 15. Hola K. Graphitic nitrogen triggers red fluorescence in carbon dots. ACS Nano. 2017; 11: 12402–12410.
13. 16. Nworie FS, Nwabue FI. Synthesis, Optimization, Characterization and Antimicrobial Studies of Cu (II) and Co (III) Complexes of Bis(2,2/-methylylidene phenol) diaminoethane. Chemistry Journal of Moldova, General, Industrial and Ecological Chemistry.2017; 12(2): 41-49.
14. 17. Kezerle A, Velic N, Hasenay K D(2018) Lignocellulosic materials as adsorbents: Adsorption of MEB and Congo red on brewers spent grain. Croat. Chem. Acta.2018; 91:53-64. 18. Mokkapati RP, Ratnakaram VN, Mokkapati JS. Utilization of agro-waste for removal of toxic hexavalent chromium: surface interaction and mass transfer studies. Int,J. Environ. Sci. Technol. 2017; 10:017-037.
15. 19. Li H.Water-soluble fluorescent carbon quantum dots and photocatalyst design. Angew. Chem. Int. Ed.2010; 49: 4430–4434.
16. 20. Chen BC, Li CD, Zhang J, Kan JF, Jiang TT, Zhou J, Ma HM. Sensing and imaging of mitochondrial viscosity in living cells using a red fluorescent probe with a long lifetime. Chem Commun.2019; 55:7410-7413. 21. Arcudi F. Rationally designed carbon dots nanodots towards pure white light emission. Angew. Chem. Int. Ed.2016; 56: 4170–4173.
17. 22. Nworie FS, Nwabue F, Ikelle I, Ogah A, Elom N, Ilochi N, Itumoh E, Oroke C.Activated plantain peel biochar as adsorbent for sorption of Zinc (II) ions: Equilibrium and kinetic studies. Journal of the Turkish Chemical Society, Section A.2018; 5(3), 1257-1270 .
18. 23. Zhao G, Li J, Ren X, Chen C, Chen X. Few-layered graphene oxide nanosheets as superior sorbents for heavy metal ion pollution management. Environ. Sci.Technol.2011; 45(24): 10454–10462.
19. 24. Ghaedi M, Montazerozohori M, Soylak M (2007) Solid phase extraction method for selective determination of Pb(II) in water samples using 4-(4-methoxybenzylidenimine) thiophenole. Journal of Hazardous Materials.2017; 142: 368–373. 25. Nworie FS. Spectral, Thermal and In Vitro Antibacterial Studies on Cadmium(II)–bis(2,2/-methylidenephenol)diaminoethane. Journal of the Turkish Chemical Society Section A: Chemistry .2018;5 (3): 1029-1036.