Designing an Optimal Ion Adsorber at the Nanoscale: The Unusual Nucleation of AgNP/Co²⁺–Ni²⁺ Binary Mixtures

Abstract

Selective removal of heavy metals from water is a complex topic. We present a theoreticalcomputational approach, supported by experimental evidences, to design a functionalised nanomaterial able to selectively capture metallic ions from water within a self-assembling process. A theoretical model is used to map an experimental mixture of Ag nanoparticles (AgNPs) and either Co 2+ or Ni 2+ onto an additive highly asymmetric attractive Lennard-Jones binary mixture. Extensive NVT (constant number of particles, volume and temperature) Monte Carlo simulations are performed to desume the set of parameters that first induce aggregation amongst the two species in solution, and then affect the morphology of the aggregates. The computational predictions are thus compared to the experimental re-1 arXiv:1908.01184v2 [cond-mat.soft] 8 Aug 2019sults. The gathered insights can be used as guidelines for the prediction of an optimal design of a new generation of selective nanoparticles to be used for metallic ion adsorption hence for maximising the trapping of ions in an aqueous solution.

Silver Nanoparticles as Colorimetric Sensors for Water Pollutants

“…This represents a remarkable opportunity for their use in environmental monitoring applications, especially for silver nanoparticles (AgNPs), that are very easy to prepare, versatile and cheap materials [52,53]. Moreover, advances in the ligand chemistry of metal nanoparticles has opened up new opportunities to fabricate colorimetric sensors to assay various chemical and biomolecular species with good selectivity and sensitivity, which can thus be identified by visual readouts [54][55][56].…”

X‐ray and UV photoelectron spectroscopy of Ag nanoclusters

“…Optical features are probably the most studied for the ease of measurement and for their use in numerous fields of applications such as biomedicine, 4,5 biotechnology, 6,7 energy, [8][9][10] optics, and optoelectronics. [11][12][13][14][15][16][17][18] Silver NPs (Ag NPs) represent an example of noble metal NPs with peculiar properties, according to the principle for which the material properties can change as a function of its size. It is well known that bulk Ag is a good electrical and thermal conductor and has a highly reflective surface.…”

Silver Nanoparticles for Water Pollution Monitoring and Treatments: Ecosafety Challenge and Cellulose-Based Hybrids Solution

“…Many methods for synthesizing stable AgNPs by chemical, physical and biological processes, using both bottom-up and top-down approaches, have been investigated [64][65][66][67][68]. The well-assessed bottom up approach is based on a wet reduction of Ag + ions in the presence of capping agents.…”

“…The well-assessed bottom up approach is based on a wet reduction of Ag + ions in the presence of capping agents. Generally, hydrophilic AgNPs can be synthesized starting from water solution of AgNO3 in presence of ligand molecule, and adding a reducing agent, such as sodium borohydride or formic acid [24,[68][69][70][71].…”

“…By choosing the appropriate method and experimental parameters for the synthesis it is possible to control shapes and obtain spheres (AgNPhs), cubes (AgNCs), stars (AgNSs) and rods (AgNRs) . Some examples with TEM images showing AgNPs with different geometries and shapes are presented in Figure 1 [68,81,88]. Among other shapes, the spherical one is the most symmetrical and is the most used because of the easy synthetic control of reproducibility and monodispersity, both being key aspects for ensuring the repeatability of experiments and results.…”