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

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 À 2 and 150 μA cm À 2 for a 50 μM Pb 2 + and Cu 2 + 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.

Novel Aspects in the Voltametric Determination of Heavy Metals: A Minireview

“…While the sensitivity to detect copper pollution was sufficient, it was not satisfactory for lead United States Environmental Protection Agency. The 92% w/w hydroxyapatite composite, which showed a ratio of approximately 1:1 between the exposed region of hydroxyapatite and carbon (by the Brunauer-Emmett-Teller method), always showed a mean maximum redissolving oxidation intensity of approximately 250 μA/cm 2 and 150 μA/cm 2 for a 50 μM Pb 2+ and Cu 2+ solution, respectively [54]. For the determination of Pb and Cu ions in lake water samples, a glassy carbon electrode was formed with multiwall carbon nanotubes, Nafion and ZIF-67 (ZIF-67/MWCNT/Nafion-GCE).…”

Recent Advances in Wastewater Treatment by Utilisation of Bio-waste-derived Hydroxyapatite

“…Adsorption mechanism was described as pseudo-second-order kinetic model and the best fitted to Langmuir model. 49 performed an original study by testing Cu(II) and Pb(II) detection performance of high surface-activated carbon and n-HAp composite electrodes. The amount of n-HAp ranged between 84-96 wt%.…”

Interface properties of hydroxyapatite in ternary composites cathodes for electromethanogenesis

“…Similarly, Gomez et al 35 ). 38 Based on our previous experience with conductive carbonbased HAP composites, 39,40 we recently proposed hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 , HAP) 41,42 as a key modifier capable of altering the product distribution of Cu-decorated N-doped graphene nanosheets. 43 This modification directs the electrocatalytic reduction of CO 2 towards formate production.…”