Air Stable Magnetic Bimetallic Fe–Ag Nanoparticles for Advanced Antimicrobial Treatment and Phosphorus Removal

Abstract

We report on new magnetic bimetallic Fe-Ag nanoparticles (NPs) which exhibit significant antibacterial and antifungal activities against a variety of microorganisms including disease causing pathogens, as well as prolonged action and high efficiency of phosphorus removal. The preparation of these multifunctional hybrids, based on direct reduction of silver ions by commercially available zerovalent iron nanoparticles (nZVI) is fast, simple, feasible in a large scale with a controllable silver NP content and size. The microscopic observations (transmission electron microscopy, scanning electron microscopy/electron diffraction spectroscopy) and phase analyses (X-ray diffraction, Mössbauer spectroscopy) reveal the formation of Fe₃O₄/γ-FeOOH double shell on a "redox" active nZVI surface. This shell is probably responsible for high stability of magnetic bimetallic Fe-Ag NPs during storage in air. Silver NPs, ranging between 10 and 30 nm depending on the initial concentration of AgNO₃, are firmly bound to Fe NPs, which prevents their release even during a long-term sonication. Taking into account the possibility of easy magnetic separation of the novel bimetallic Fe-Ag NPs, they represent a highly promising material for advanced antimicrobial and reductive water treatment technologies.

Direct synthesis of antimicrobial coatings based on tailored bi-elemental nanoparticles

“…So far, the synthesis of NPs composed of two elements (bi-NPs) has stimulated research efforts [8][9][10][11][12][13] due to their remarkably enhanced catalytic, microbicidal, optical, electronic, and mechanical properties, which goes beyond the mere sum of the effects of the constituent materials. Ag/Fe a Author to whom correspondence should be addressed.…”

“…All authors have given approval to the final version of the manuscript. NPs allow their removal from a solution after the Ag microbicidal effect has been exploited, 8 while the combination of Au and Pt into bimetallic NPs shows a remarkable microbicidal effect that the single metal NPs (either Au or Pt) do not present. 9 Small quantities of Pd inside Pd-W NPs metal are sufficient to enhance the cluster stability and catalytic properties due to the formation of ultra-active Pd hot-spots.…”

Cu/Cu2O/CuO loaded on the carbon layer derived from novel precursors with amazing catalytic performance

“…The greater catalytic activity of the material can be ascribed to their large surface areas compared to other Cu 2 O particles (Table 1) due to highly porous supporting materials promoting diffusion of pollutant molecules to the metal catalytic sites. The supporting matrices which reported in other literature possess low surface areas, and the nanoparticles are usually imbedded into the supports, results in the poor accessibility of catalysts towards targets (Markova et al, 2013). Thereby the porous structure may accelerate diffusion of reactants and products, which results in more rapid catalytic degradation of pollutants and leads to greater efficiency of catalysis.…”

MOF derived porous carbon supported Cu/Cu 2 O composite as high performance non-noble catalyst

“…Therefore, increasing efforts have been made by loading metal NPs on various supports [6e8]. The supporting matrices reported in literature generally possess low surface areas, and the NPs are usually imbedded into the supports, which results in the poor accessibility of catalysts towards targets [9]. Thereby, supporting materials, with high porous structure, may provide multiple accessible channels for diffusion and transport to take full advantage of the excellent catalytic functionalities of metal NPs.…”