Synthesis and characterization of Cu(OH)2-NWs-PVA-AC Nano-composite and its use as an efficient adsorbent for removal of methylene blue

Sivarama Krishna Lakkaboyana; Khantong Soontarapa; Nabel Kalel Asmel; Vinay Kumar; Ravi Kumar Marella; Ali Yuzir; Wan Zuhairi Wan Yaacob

doi:10.1038/s41598-021-84797-3

Synthesis and characterization of Cu(OH)₂-NWs-PVA-AC Nano-composite and its use as an efficient adsorbent for removal of methylene blue

Sci Rep. 2021 Mar 11;11(1):5686. doi: 10.1038/s41598-021-84797-3.

Authors

Sivarama Krishna Lakkaboyana^{1

2}, Khantong Soontarapa^{3

4}, Nabel Kalel Asmel⁵, Vinay Kumar⁶, Ravi Kumar Marella⁷, Ali Yuzir⁸, Wan Zuhairi Wan Yaacob⁹

Affiliations

¹ Department of Chemical Technology, Faculty of Sciences, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand. svurams@gmail.com.
² Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand. svurams@gmail.com.
³ Department of Chemical Technology, Faculty of Sciences, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand. khantong.s@chula.ac.th.
⁴ Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Pathumwan, Bangkok, 10330, Thailand. khantong.s@chula.ac.th.
⁵ Building and Construction Technology Engineering, Northern Technical University, 41002, Mosul, Iraq.
⁶ Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India.
⁷ Department of Chemistry (H & S), PACE Institute of Technology & Sciences, Ongole, Andhra Pradesh, 523001, India.
⁸ Department of Environmental Engineering and Green Technology (EGT), MJIIT- Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100, Kuala Lumpur, Malaysia.
⁹ Geology Program, School of Environmental Science and Natural Resources, FST, University Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia.

Abstract

The present study focused on the synthesis of copper hydroxide nanowires decorated on activated carbon (Cu(OH)₂-NWs-PVA-AC). The obtained Cu(OH)₂-NWs-PVA-AC Nano-composite was distinguished by XRD, SEM, EDX, BET, FTIR and XPS respectively. Besides, different variables such as solution p^H, and initial dye concentration, contact time, and temperature were performed on the adsorption efficiency of MB in a small batch reactor. Further, the experimental results are analyzed by various kinetic models via PFO, PSO, intra-particle diffusion and Elovich models, and the results revealed that among the kinetic models, PSO shows more suitability. In addition, different adsorption isotherms were applied to the obtained experimental data and found that Langmuir-Freundlich and Langmuir isotherm were best fits with the maximum adsorption capacity of 139.9 and 107.6 mg/g, respectively. The Nano-composite has outstanding MB removal efficiency of 94-98.5% with a span of 10 min. and decent adsorption of about 98.5% at a p^H of 10. Thermodynamic constants like Gibbs free energy, entropy, and enthalpy were analyzed from the temperature reliance. The results reveal the adsorption processes are spontaneous and exothermic in nature. The high negative value of ΔG° (- 44.11 to - 48.86 kJ/mol) and a low negative value of ΔH° (- 28.96 kJ/mol) show the feasibility and exothermic nature of the adsorption process. The synthesized dye was found to be an efficient adsorbent for the potential removal of cationic dye (methylene blue) from wastewater within a short time.