Synthesis of poly (acrylic acid) modified graphene/MoS2 heterostructure-based composite: an effective removal of Pb(II), Cd(II) and Zn(II) from wastewater

Salami Hammed Olawale; Waleed Alahmad; Ibrahim A Darwish; Mohamed Aly Saad Aly; Mohammad Ashfaq; Charoenkwan Kraiya

doi:10.1038/s41598-025-94671-1

Synthesis of poly (acrylic acid) modified graphene/MoS₂ heterostructure-based composite: an effective removal of Pb(II), Cd(II) and Zn(II) from wastewater

Sci Rep. 2025 Apr 5;15(1):11701. doi: 10.1038/s41598-025-94671-1.

Authors

Salami Hammed Olawale^{1

2}, Waleed Alahmad¹, Ibrahim A Darwish³, Mohamed Aly Saad Aly^{4

5}, Mohammad Ashfaq⁶, Charoenkwan Kraiya^{7

8}

Affiliations

¹ Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
² Electrochemistry and Optical Spectroscopy Center of Excellence, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
³ Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, 11451, Riyadh, Saudi Arabia.
⁴ School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
⁵ Department of Electrical and Computer Engineering at Georgia Tech Shenzhen Institute (GTSI), Shenzhen, Guangdong, 518055, China.
⁶ Department of Biotechnology & University Centre for Research & Development (UCRD), Chandigarh University, Gharaun, Mohali, Punjab, 140413, India.
⁷ Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand. charoenkwan.k@chula.ac.th.
⁸ Electrochemistry and Optical Spectroscopy Center of Excellence, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand. charoenkwan.k@chula.ac.th.

Abstract

Heavy metal contaminants have attracted widespread attention due to their severe toxicity and bioaccumulation. In this study, a novel graphene (EG)/molybdenum disulfide (MoS₂) modified with poly (acrylic acid) (PAA) composites (EG/MoS₂/PAA) were successfully synthesized via a one-step hydrothermal method and effectively removed Pb(II)_, Zn(II)_, and Cd(II) ions from wastewater. The incorporation of PAA within the EG/MoS₂ significantly improved sorption ability. The EG/MoS₂/PAA composite was characterized using XRD, FTIR, TEM, Raman, SEM-EDS, EIS, and cyclic voltammetry, which confirmed the successful synthesis of the EG/MoS₂/PAA composite. The adsorption isotherm and kinetic of Pb(II), Zn(II), and Cd(II) were fitted with the Temkin isotherm and pseudo-second-order model, respectively. The maximum adsorption capacities (q_max) obtained using the Langmuir model were 47.13 mg/g for Pb(II) at pH 5, while 12.59 and 12.89 mg/g for Zn(II) and Cd(II) at pH 7. In the presence of interfering cations (i.e., Na⁺, Cu²⁺, Co²⁺, Fe³⁺, and Mg²⁺), the EG/MoS₂/PAA adsorbent exhibited high selectivity and excellent reusability after three cycles. The adsorption mechanism of Pb(II), Zn(II), and Cd(II) onto the EG/MoS₂/PAA composite surface was found to be primarily controlled by complexation and electrostatic interaction. This novel EG/MoS₂/PAA adsorbent has excellent suitability for practical application in the treatment of highly contaminated wastewater.

Keywords: EIS; Hydrothermal; MoS2; Poly (acrylic acid); Temkin; Toxicity.

Abstract

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