High‐Content Hydroxyapatite Carbon Composites for the Electrochemical Detection of Heavy Metal Cations in Water

Sensing heavy metal cations: The great performance of nanostructured hydroxyapatite (Hap) in adsorbing heavy metal cations with the good electrical conductivity of high-surface carbon materials is combined for the crafting of high-content hydroxyapatite electrodes (Hap 84–96 wt.%) endowed with the synergistic capability of detection and adsorption of heavy metal cations (Pb²⁺ and Cu²⁺) by water solutions.

Abstract

The great performance of nanostructured hydroxyapatite (Hap) in adsorbing heavy metal cations with the good electrical conductivity of high-surface carbon materials was here combined for the crafting of high-content hydroxyapatite electrodes (Hap 84–96 wt.%) endowed with the synergistic capability of detection and adsorption of heavy metal cations by water solutions. To improve the sustainability of the sensor, a mesoporous carbon (derivable by bio-waste) was selected as scaffold for depositing Hap by simply co-precipitation. The composite with 92 wt.% of Hap, which exhibited ca. 1 : 1 ratio between the exposed area of Hap and carbon (by Brunauer-Emmett-Teller method), invariably showed an average stripping oxidation peak intensity of ca. 250 μA cm⁻² and 150 μA cm⁻² for a 50 μM Pb²⁺ and Cu²⁺ solution, respectively. Control experiments showed that the above sensor outperformed the sensibility of two low-content Hap electrodes (4 and 8 wt.%), representative of the best performing Hap-carbon composites available in literature.

Zum Volltext