A ligand-anchored optical composite material for efficient vanadium(ii) adsorption and detection in wastewater

Abstract

Herein, we developed a new and simple application utilizing a solid ligand-anchored composite material fabricated by the immobilization of the 8-hydroxyquinoline ligand onto mesoporous silica nanospheres for the optical detection and adsorption of vanadium (V(II)) ions in wastewater samples. The new composite materials was exhibited the significant color upon addition of trace concentrations of V(II) ions. Using this composite material, the V(II) ion detection responses up to nanomolar concentrations (∼0.15 μg L⁻¹) were obtained with immediate response times (in seconds). The adsorption trend was highly competent according to Langmuir isotherms, and the highest removal capacity of the composite material for the V(II) ions was 492.61 mg g⁻¹ ions. Although the wastewater samples contained active constituents, the composite material selectively detected the V(II) ions in wastewater samples such as coker gasoline; moreover, several foreign ions were tested as competing ions; however, they did not affect the detection and removal of V(II) ions due to the strong affinity of the composite material to the V(II) ions under suitable conditions. The data also emphasize that the composite material is highly suitable due to its selectivity, sensitivity, low-cost and suitable approach for the capture of V(II) ions from polluted waters; moreover, the composite material can be easily used with multiple regeneration/reuse cycles using 0.10 M HCl acid to efficiently remove V(II) ions from the used composite material and form the V(II)-free composite material again. The use of this composite material for V(II) ion screening indicates that it can be an alternative tool to achieve a time- and cost-saving effective laboratory assay.