Fabrication of efficient surface ion-imprinted materials based on rice husk ash for Cu2+ ion detection in crayfish and Cu2+ ion adsorption from tap water

Abstract

With the growing emphasis on circular economies and green chemistry, the biosorbent-based detection and capture of Cu²⁺ ions have become increasingly important. This study on fabrication of Cu²⁺ ion-imprinted materials (RHA-CIIMs) was conducted using surface ion imprinting technology with MCM-41 derived from rice hull ash (RHA) as the support material. A comparison of RHA-CIIMs and non-imprinted materials (RHA-CNIMs) reveals that RHA-CIIMs with a low LOD of 4.03 μg L⁻¹ has superior selectivity and sensitivity for Cu²⁺ ions. Meanwhile, RHA-CIIMs could accurately detect Cu²⁺ ions in crayfish with a relative standard deviation of 2.1%. Moreover, RHA-CIIMs demonstrated 128.7 mg g⁻¹ adsorption capacity for Cu²⁺ ions, indicating their potential as a Cu²⁺ ion adsorbent. Based on their adsorption properties, almost 101.7% of Cu²⁺ was removed from tap water samples. Furthermore, their adsorption kinetics was accurately described by the pseudo-second-order model, while the sorption isotherm conformed to the Langmuir model.