Ultra fast and highly efficient recovery of cadmium with graphene oxide-chitosan grafted by nickel ferrite as a recyclable adsorbent and atomic scale mechanism

Chaoke Bulin; Ting Guo

doi:10.1016/j.scitotenv.2025.179974

Ultra fast and highly efficient recovery of cadmium with graphene oxide-chitosan grafted by nickel ferrite as a recyclable adsorbent and atomic scale mechanism

Sci Total Environ. 2025 Aug 20:991:179974. doi: 10.1016/j.scitotenv.2025.179974. Epub 2025 Jun 23.

Authors

Chaoke Bulin¹, Ting Guo²

Affiliations

¹ College of Material Science And Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, China; Inner Mongolia Key Laboratory of Advanced Ceramic Material and Devices, Baotou 014010, China; Key Laboratory of Green Extraction & Efficient Utilization of Light Rare-Earth Resources (Inner Mongolia University of Science and Technology), Ministry of Education, Baotou 014010, China. Electronic address: quan820720@126.com.
² College of energy and environment, Inner Mongolia University of Science and Technology, Baotou 014010, China.

PMID: 40555050
DOI: 10.1016/j.scitotenv.2025.179974

Abstract

Adsorption is a fascinating technique for heavy metal scavenging. In this work, graphene oxide-chitosan grafted by nickel ferrite (NiFe₂O₄-GO-CS) was fabricated for adsorptive recovery of Cd(II). Atomic scale mechanism was clarified via exploiting model fitting, spectrometric investigation and the hard soft acid base (HSAB) theory. Result confirms, adsorption equilibrium of NiFe₂O₄-GO-CS on Cd(II) is established in 14 min, with recovery percent and quantity adsorbed 99.07 % and 396.29 mg·g^-1, respectively, manifesting ultra fast and highly efficient recovery. Paramagnetic NiFe₂O₄ enables convenient separation of NiFe₂O₄-GO-CS, bringing satisfactory recyclability: recovery percent and quantity adsorbed are 86.72 % and 346.89 mg·g^-1 after five consecutive cycles. Adsorption mechanism is delineated from three perspectives. From thermodynamic perspective, adsorption of Cd(II) on NiFe₂O₄-GO-CS surface is endothermic, randomness increasing and spontaneous. From kinetic perspective, surface reaction is the rate limiting stage. From atomic perspective, CO, CO, -C(=O)NH-, -NH₂ and OH participate in Cd(II) uptake. This work provides insights for constructing high efficiency bio adsorbent towards recovery of valuable metals from wastewater, dictating important implications in both resource and environmental aspects.

Keywords: Adsorption mechanism; Cadmium; Nickel ferrite.