Development of Chitosan-Graphene Oxide Nanocomposite Hydrogel for Adsorption and Recovery of Platinum from Aqueous Solutions

Khademi, Farnoosh; Baghban Salehi, Mahsa; Mortaheb, Hamid Reza; Ahmadi, Seyyed Hamid

doi:10.22034/ijche.2025.517721.1515

Development of Chitosan-Graphene Oxide Nanocomposite Hydrogel for Adsorption and Recovery of Platinum from Aqueous Solutions

Articles in Press

Document Type : Original Article

Authors

Farnoosh Khademi ¹

Mahsa Baghban Salehi ²

Hamid Reza Mortaheb ¹

Seyyed Hamid Ahmadi ¹

¹ Chemistry & Chemical Engineering Research Center of Iran (CCERCI), Pajohesh Blvd,17th Km of Tehran-Karaj Highway, Tehran, Iran

² Chemistry &amp; Chemical Engineering Research Center of Iran (CCERCI), Pajohesh Blvd,17th Km of Tehran-Karaj Highway, Tehran, Iran

10.22034/ijche.2025.517721.1515

Abstract

In this study, a nanocomposite hydrogel was synthesized from a biodegradable polymer (chitosan), grafted with acrylic acid and crosslinked by polyethyleneimine. The hydrogel was prepared via the sol–gel method to enable selective platinum removal and recovery from aqueous solutions. To enhance adsorption capacity and structural integrity, graphene oxide nanoparticles were incorporated into the network. Characterization by FTIR, BET, XRD and TGA confirmed successful formation of the chitosan–grafted acrylic acid nanocomposite hydrogel. TGA results indicated thermal stability up to 274 °C. Adsorption data were modeled using the Langmuir isotherm, yielding a maximum capacity of 217.4 mg g⁻¹. A Gibbs free energy change of –1,473J mol⁻¹ was calculated, indicating spontaneity of the process. Across three consecutive adsorption cycles, the graphene oxide–reinforced hydrogel achieved platinum uptake efficiencies of 98%, 84.42% and 70.69%. Corresponding desorption stages released 85%, 72% and 60% of the adsorbed platinum, respectively.

Keywords

Platinum

Hydrogel Sol-Gel

Surface adsorption

Selective Release

Adsorption-Desorption cycle

Subjects