Toward the Development of Disposable Electrodes Based on Holmium Orthovanadate/-Boron Nitride: Impacts and Electrochemical Performances of Emerging Inorganic Contaminants.

Rare-earth metal orthovanadates have great technological relevance in the family of rare-earth compounds owing to their excellent physical and chemical properties. A significant number of studies have been carried out on this class of compounds to exploit their electrochemical properties in virtue of variable oxidation states. But holmium vanadate (HoV) and its morphology selective synthesis have not been considered, which can have potential applications similar to the rest of the family. In this work, we propose the synthesis of superior architectures of HoV with a functionalized boron nitride (-BN) nanocomposite. The synergistic effect between HoV and -BN can have a positive effect on the physical characteristics of the nanocomposite, which can be explored for its electrochemical capacity. Here, HoV incorporated with -BN is explored for the electrochemical detection of Hg ions, which is known for its toxicity-induced environmental health hazards. The structural and compositional revelation reveals higher conductivity and faster electron transfer in the composite, which facilitates a wide working range (0.02-53.8 and 64.73-295.4 μM), low limit of detection (5 nM), higher sensitivity (66.6 μA μM cm), good selectivity over 10-fold higher concentration of other interfering compounds compared to Hg ion concentration, and good cycles stability (30 segments) toward Hg ion detection. This also envisages the morphology selective synthesis and utilization of other rare-earth metals, whose electrochemical capacities are unexplored.