Ag Nanoparticles/AgX (X=Cl, Br and I) Composites with Enhanced Photocatalytic Activity and Low Toxicological Effects

Abstract

Periodic structures induced by electron irradiation are a unique phenomenon when electron beams irradiate on the surface of some materials. These periodic structures have potential for technological applications. However, the fuzzy nature of the electron-induced structuring hinders its further exploration in such applications. In this paper, novel Ag nanoparticle/AgX (X=Cl, Br and I) composites, with enhanced photocatalytic activity and low toxicological effects, were prepared, for the first time, using electron beam irradiation. The remarkable advantage of this approach is that the Ag nanoparticles/AgX composites can be easily prepared in one-step without the need for high-pressure conditions, surfactants, ionic liquids, or reducing agents. Furthermore, our method does not involve any toxic substances, which makes the as-synthesized samples highly applicable for technological applications. The structure, morphology and physicochemical properties of the Ag nanoparticles/AgX composites were studied using various characterization techniques. Using first-principles calculations based on density functional theory and the quantum theory of atoms in molecules, we reveal how the concentration of excess electrons in the AgX materials induces the formation of the Ag nanoparticles under electron beam irradiation. These results extend the fundamental understanding of the atomic process underlying the mechanism of AgÀ X bond rupture observed during the transformation induced via electron irradiation of the AgX crystals by increasing the total number of electrons in the bulk structure. Thus, our findings provide viable guidance for the realization of new materials for the degradation of contaminated wastewater with low toxicity.

Coadsorbed Species with Halide Ligands on Silver Nanoparticles with Different Binding Affinities

“…Most of these peaks are also identified upon I − ligand exchange (AgNPs@I) and MgSO 4 aggregation (Figure 3c, red), with differences including the diminishing of weak features at 1253w and 1590 cm −1 and the rise of peaks at 1650w and 1165w cm −1 , as well as the advent of the distinctive peak at 110 cm −1 (ν(Ag−I)) in replacement of the ν(Ag−Br) peak. 15,46 Again, we confirm that the above peaks are not changed with further increases in concentrations or time allowed for ligand exchange (the maximum [Br − ] final or [I − ] final = 0.5 mM, time increases from 5 to 60 min, Figures S7 and S8). Therefore, supported by previous studies, 18,29 the strong signals could be attributed to the lack of coverage on the Ag surface by Br − or I − ligands, leaving gaps suitable for species to coadsorb.…”

SiO2-Ag Composite as a Highly Virucidal Material: A Roadmap that Rapidly Eliminates SARS-CoV-2

“…ROS can still inhibit the replication activities of DNA/plasmid and some protein enzymes, due to their interaction with phosphate/sulfate groups or even due to genetic changes [ 25 , 26 ]. All of these results, in combination with the permeability of ROS under the cell membrane, can affect the expression of proteins essential for the correct functioning of microorganisms, as well as their replication [ 24 , 27 , 28 , 29 , 30 , 31 ].…”

“…In recent years, the construction of Ag metal/semiconductor composite materials has been identified as a promising strategy for responding to the above problems. Therefore, the strong surface plasmon resonance (SPR) adsorption and high electron trapping ability of Ag NPs are beneficial for promoting the charge transmission bridge [ 29 , 50 , 51 , 52 , 53 , 54 , 55 ]. This modification of Ag NPs by light establishes a coulombic restoring force and prompts a charge density, and they are frequently used in plasmonic composites.…”

Endophytic Microorganisms From the Tropics as Biofactories for the Synthesis of Metal-Based Nanoparticles: Healthcare Applications

“…Silver as a metal has been used since ancient times due to its microbicidal and/or anti-inflammatory properties (Assis et al, 2020;Alavi and Varma, 2021;Salesa et al, 2021). As a result, it has become a key NP of easy obtention through green biosynthesis by endophytic microorganisms.…”