Novel Multi‐Function Chromoionophoric Probe‐Based Nano‐Conjugate Material for Highly Efficient Detection, Removal, and Recovery of Pd(II) and Co(II) Ions from Electronic Wastes and Electroplating Wastewater

Abstract

AbstractThis study describes the development of a multifunction chromoionophoric probe‐based nano‐conjugate material for the colorimetric determination, recovery, and removal of palladium and cobalt ions (Pd(II) and Co(II)) ions from electronic wastes and electroplating wastewater. The chromoionophoric probe‐based nano‐conjugate material was prepared using a building‐block approach by anchoring the 4‐[(E)‐(2‐hydroxyphenyl)diazenyl]‐1‐nitrosonaphthalen‐2‐ol (HDN) organic chromoionophoric probe onto nano‐spherical silica material carrier. The prepared materials were characterized using different techniques, such as TEM, SEM XRD, and BET. The HDN chromoionophoric probe‐based nano‐conjugate material was evaluated for its effectiveness in detecting and removing Pd(II) and Co(II) ions from electronic wastes and electroplating wastewater by testing various parameters such as pH, sensing system temperature, reaction kinetic, nano‐conjugate material amount, stability of the chromoionophoric probe‐based nano‐conjugate material and the existence of other coexisting metal ions. The HDN chromoionophoric probe‐based nano‐conjugate material demonstrated high selectivity and sensitivity for the colorimetric ion‐sensing of Pd(II) and Co(II) ions, with a detection limit of 7.18 and 208 nM, respectively. The method displayed optimal sensing at pH levels of 6.0 and 8.0 for Pd(II) and Co(II) ions, respectively, and the presence of other metal ions did not meaningfully influence the performance of the ion‐detection due to the powerful ability of the chromoionophoric probe‐based nano‐conjugate material. The adsorption capacity of the chromoionophoric probe‐based nano‐conjugate material towards Pd(II) and Co(II) ions was investigated and the outcomes were 163.40 and 128.57 mg/g, respectively. The chromoionophoric probe‐based nano‐conjugate material could be regenerated by eluting the adsorbed Pd(II) and Co(II) ions with 0.15 M HCl solution. In addition, the material could be reused multiple times, with almost no decrease in its initial performance after regeneration. Based on the findings, the chromoionophoric probe‐based nano‐conjugate material shows potential for environmental recovery, removal, and detection of Pd(II) and Co(II) ions from electronic wastes and electroplating wastewater, indicating its potential as a multi‐function solution for environmental concerns and issue and could be even commercialized and used at a larger scale.