Exploring Carbon Nanosheets for Adsorption of Cr(VI) from Aqueous Solution

IJEP 43(11): 1036-1042 : Vol. 43 Issue. 11 (November 2023)

Madhur Kant1, Mousumi Sen1* and Fehmeeda Khatoon2

1. Amity University, Department of Chemistry, Amity Institute of Applied Sciences, Greater Noida – 201 313, Uttar Pradesh, India
2. Jamia Malia Islamia University, New Delhi – 110 025, India


Toxic pollutants in wastewater must be reduced in order to protect the aquatic ecosystem’s stability and public health. It is vitally necessary to find cost-efficient and efficient technology for treating wastewater from horticulture, aquaculture and industrial sources. It has been demonstrated that nitrogen-doped carbon nanosheets (N-CNS), which are produced by hydrothermal reaction from glycerol, sulphuric acid and melamine, have strong adsorptive behaviour against hazardous aqueous pollutants, such as heavy metals and organic compounds. By incorporating nitrogen, the CNS’s overall elemental composition is changed, encouraging CNS interactions with contaminants. The current study’s goal was to look into the possibilities of chromium (VI) [Cr(VI)] adsorption on the CNS from a liquid solution containing the metal mixture, that is Cr(VI) and Ni(II). It was carried out in a batch bioreactor. The result found optimal pH to be 2.0 for Cr(VI) adsorption from the mixture of both metals. The Cr(VI) adsorption was enhanced when the starting metal concentration was upto 50 mg/L. A maximum removal of 69.6 mg/g was seen when pH was 2.0 at 50 mg/L initial Cr(VI) concentration. Freundlich and Langmuir adsorption isotherms were used to calculate the equilibrium constants for adsorption. Through fitted curve and correlation coefficient (R2), we found Langmuir isotherm model as the best fit, indicating a homogeneous surface of the CNS.


Chromium (VI), carbon nanosheets, Specific metal uptake, Adsorption


  1. Guo, H., et al. 2015. Preparation of graphene oxide-based hydrogels as efficient dye adsorbents for wastewater treatment. Nanoscale Res. Lett., 10: 0–9. DOI: 10.1186/s11671-015-0931-2.
  2. Wang, G., et al. 2017. Synthesis of a novel illite@ carbon nanocomposite adsorbent for removal of Cr(VI) from wastewater, J. Env. Sci., 57: 62–71. DOI: 10.1016/j.jes.2016.10.017.
  3. Setshedi, K.Z., et al. 2015. High-performance towards Cr(VI) removal using multi-active sites of polypyrrole-graphene oxide nanocomposites: Batch and column studies. Chem. Eng. J., 262: 921–931. DOI: 10.1016/j.cej.2014.10.034.
  4. Samuel, M.S., et al. 2019. Efficient removal of chromium(VI) from aqueous solution using chitosan grafted graphene oxide (CS-GO) nanocomposite. Int. J. Biol. Macromol., 121: 285–292. DOI: 10.10 16/j.ijbiomac.2018.09.170.
  5. Zhang, G., et al. 2018. Preparation of ZnIn2S4nanosheet-coated CdS nanorod heterostructures for efficient photocatalytic reduction of Cr(VI). Appl. Catal. B Env., 232:164–174. DOI: 10.1016/j.apcat b.2018.03.017.
  6. Rathour, R.K.S., J. Bhattacharya and A. Mukherjee. 2020. Selective and multicycle removal of Cr(VI) by graphene oxide–EDTA composite: Insight into the removal mechanism and ionic interference in binary and ternary associations. Env. Tech. Innov., 19:100851. DOI: 10.1016/j.eti.2020.100851.
  7. Xu, J., et al. 2019. Synergistic removal of Cr(VI) and dye contaminants by 0D/2D bismuth molybdate homojunction photocatalyst under visible light. Appl. Surf. Sci., 484:1080–1088. DOI: 10.1016/j.apsus c.2019.04.146.
  8. Chen, L., et al. 2018. Flexible design of carbon nanotubes grown on carbon nanofibers by PECVD for enhanced Cr(VI) adsorption capacity. Sep. Purif. Tech., 207:406–415. DOI: 10.1016/j.seppur.2018. 06.065.
  9. Ansari, M.O., et al. 2017. Anion selective pTSA doped polyaniline@graphene oxide-multiwalled carbon nanotube composite for Cr(VI) and Congo Red adsorption. J. Colloid Interface Sci., 496: 407–415. DOI: 10.1016/j.jcis.2017.02.034.
  10. Ali, I. and V.K. Gupta. 2007. Advances in water treatment by adsorption technology. Nat. Protoc., 1:2661–2667. DOI: 10.1038/nprot.2006.370.
  11. Liu, W.J., H. Jiang and H.Q. Yu. 2015. Development of biochar-based functional materials: Toward a sustainable platform carbon material. Chem. Rev., 115: 12251–12285. DOI: 10.1021/acs.chemrev. 5b00195.
  12. Wang, W., et al. 2014. A novel bottom-up solvother-mal synthesis of carbon nanosheets. J. Mater. Chem. A., 2:2390–2396.
  13. Suhag, D., et al. 2015. Hydrothermal synthesis of nitrogen doped graphene nanosheets from carbon nanosheets with enhanced electrocatalytic properties. RSC Adv., 5:39705–39713. DOI: 10.1039/c5ra05060j.
  14. Wan, Z., et al. 2020. Customised fabrication of nitrogen-doped biochar for environmental and energy applications. Chem. Eng. J., 401:126136. DOI: 10.1016/j.cej.2020.126136.
  15. Kasera, N., S. Hall and P. Kolar. 2021. Effect of surface modification by nitrogen-containing chemicals on morphology and surface characteristics of N-doped pine bark biochars. J. Env. Chem. Eng., 9:105161. DOI: 10.1016/j.jece.2021.105161.
  16. Chen, W., et al. 2018. Investigation on biomass nitrogen-enriched pyrolysis: Influence of temperature. Bioresour. Tech., 249: 247–253. DOI: 10.101 6/j.biortech.2017.10.022.
  17. Yuan, S., Z. Tan and Q. Huang. 2018. Migration and transformation mechanism of nitrogen in the biomass–biochar–plant transport process. Renew. Sustain. Energy Rev., 85: 1–13. DOI: 10.1016/j.rs er.2018.01.008.
  18. Tian, Y., et al. 2013. Nitrogen conversion in relation to NH3and HCN during microwave pyrolysis of sewage sludge. Env. Sci. Tech., 47:3498–3505. DOI: 10.1021/es304248j.
  19. Leng, L., et al. 2019. Nitrogen containing functional groups of biochar: An overview. Bioresour. Tech., 122286. DOI: 10.1016/j.biortech.2019.122286.
  20. Wan, Z., et al. 2020. Sustainable impact of tartaric acid as electron shuttle on hierarchical iron-incorporated biochar. Chem. Eng. J., 395:125138. DOI: 10.1016/j.cej.2020.125138.
  21. Ma, J.C. and D.A. Dougherty. 1997. The cation-p interaction. Chem. Rev., 97:1303–1324. DOI: 10.1021/cr9603744.
  22. APHA. 1989. Standard methods for examination of water and wastewater (17th edn). American Public Health Association, Washington D.C.
  23. Niu, L., et al. 2010. Efficient removal of Cu(II), Pb(II), Cr(VI) and As(V) from aqueous solution using an aminated resin prepared by surface-initiated atom transfer radical polymerization. Chem. Eng. J., 165: 751–757.
  24. Tuzen, M. and M. Soylak. 2007. Multiwalled carbon nanotubes for speciation of chromium in environ-mental samples. J. Hazard. Mater., 147: 219–225.
  25. Wen, Y., et al. 2011. Adsorption of Cr(VI) from aqueous solutions using chitosan-coated fly ash composite as biosorbent. Chem. Eng. J., 175:110–116.
  26. Saha, B. and C. Orvig. 2010. Biosorbents for hexavalent chromium elimination from industrial and municipal effluents. Coord. Chem. Rev., 254: 2959–2972.
  27. Zhang, Y.J., et al. 2015. Adsorption of Cr(VI) on bamboo bark-based activated carbon in the absence and presence of humic acid. Colloids Surf. A Physicochem. Eng. Asp., 481:108–116.
  28. Li, T., et al. 2014. Hydrothermal carbonization synthesis of a novel montmorillonite supported carbon nanosphere adsorbent for removal of Cr (VI) from wastewater. Appl. Clay Sci., 93–94: 48–55.
  29. Chen, L. F., et al. 2011. Synthesis of an Attapulgite clay@carbon nanocomposite adsorbent by a hydrothermal carbonization process and their application in the removal of toxic metal ions from water. Langmuir. 27: 8998–9004.
  30. Bhaumik, M.A., et al. 2011. Enhanced removal of Cr(VI) from aqueous solution using polypyrrole/Fe3O4magnetic nanocomposite. J. Hazard. Mater., 190: 381–390.
  31. Bhaumik, M., et al. 2012. Removal of hexavalent chromium from aqueous solution using polypyrrole-polyaniline nanofibers. Chem. Eng. J., 181–182: 323–333.