Mechanism of Antibacterial Activity via Morphology Change of α-AgVO<sub>3</sub>: Theoretical and Experimental Insights

Oliveira, Regiane Cristina de; Foggi, Camila Cristina de; Teixeira, Mayara Mondego; Silva, Maya Dayana Penha da; Assis, Marcelo; Francisco, Eric Mark; Pimentel, Bruna Natália Alves da Silva; Pereira, Paula Fabiana dos Santos; Vergani, Carlos Eduardo; Machado, Ana Lúcia; Andrés, Juan; Gracia, Lourdes; Longo, Elson

doi:10.1021/acsami.7b00920

Cited by 60 publications

(73 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Figure shows this evolution from 0 to 5 min for the AgCl (Figure A–F), AgBr (Figure G–L) and AgI (Figure M–R) samples. The formation of small nanoparticles was observed for all the samples and was very similar to those obtained for silver oxides such as α‐Ag 2 WO 4 , β‐Ag 2 WO 4 , Ag 2 CrO 4 , β‐Ag 2 MoO 4 , and β‐AgVO 3 when they come into contact with an electron beam at different voltages of acceleration. It is still possible to observe that the phenomenon is different for the three AgX materials studied.…”

Section: Resultssupporting

confidence: 78%

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

et al. 2020

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Resultssupporting

confidence: 78%

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

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Several nanoparticles (NPs) have demonstrated broad-spectrum antibacterial properties against both Gram-positive and Gram-negative bacteria, mainly silver NPs, zinc oxide NPs, carbon nanotubes and iron oxide NPs [ 6 , 7 , 8 ]. The control of NPs morphology and structure is an important factor because antimicrobial performance is highly influenced by the morphology, shape and size of the particles [ 9 , 10 ]. The increase in surface area or the design of an appropriate sized and shaped nanoparticle with desirable surface properties can lead to an improvement of bactericidal activity.…”

Section: Introductionmentioning

confidence: 99%

Novel Antimicrobial Titanium Dioxide Nanotubes Obtained through a Combination of Atomic Layer Deposition and Electrospinning Technologies

et al. 2018

View full text Add to dashboard Cite

The search for new antimicrobial substances has increased in recent years. Antimicrobial nanostructures are one of the most promising alternatives. In this work, titanium dioxide nanotubes were obtained by an atomic layer deposition (ALD) process over electrospun polyvinyl alcohol nanofibers (PVN) at different temperatures with the purpose of obtaining antimicrobial nanostructures with a high specific area. Electrospinning and ALD parameters were studied in order to obtain PVN with smallest diameter and highest deposition rate, respectively. Chamber temperature was a key factor during ALD process and an appropriate titanium dioxide deposition performance was achieved at 200 °C. Subsequently, thermal and morphological analysis by SEM and TEM microscopies revealed hollow nanotubes were obtained after calcination process at 600 °C. This temperature allowed complete polymer removal and influenced the resulting anatase crystallographic structure of titanium dioxide that positively affected their antimicrobial activities. X-ray analysis confirmed the change of titanium dioxide crystallographic structure from amorphous phase of deposited PVN to anatase crystalline structure of nanotubes. These new nanostructures with very large surface areas resulted in interesting antimicrobial properties against Gram-positive and Gram-negative bacteria. Titanium dioxide nanotubes presented the highest activity against Escherichia coli with 5 log cycles reduction at 200 μg/mL concentration.

show abstract

“…Because of the Wulff construction, the equilibrium morphology of a given material can be obtained using ab initio calculations [131][132][133][134][137][138][139][140][141][142] . The procedure to obtain the complete set of morphologies, based on the Wulff construction and the surface energy, has been previously presented and employed as guide to match with experimental morphologies obtained for different binary oxides such as: Co 3 80 . Then, we can apply our methodology to develop a consistent and reliable set of models for the morphology and corresponding exposed material surfaces.…”

Section: Concept Of Surface Energymentioning

confidence: 99%

“…In our laboratories, it has been a long-standing objective to develop platforms that enable the experimental and computational investigation of semiconductors through modeling. In this research field, our group has developed different semiconductors such as α-Ag 2 WO 4 , Ag 3 PO 4 :Mo, PbMoO 4 , HA@Ag (hydroxyapatite decorated with silver), ZnWO 4 , NiWO 4 , and α−AgVO 3 with good performance as photocatalytic materials for the degradation of organic dyes [72][73][74][75][76] and antibacterial agents [77][78][79][80][81] .…”

mentioning

confidence: 99%

Reading at exposed surfaces: theoretical insights into photocatalytic activity of ZnWO4

et al. 2018

Self Cite

View full text Add to dashboard Cite

Understanding the criteria warranting the existence, stability, and activity of a given configuration of atoms has pivotal relevance in chemical and materials science. Photocatalysts, traditionally semiconductors, are essential for processes ranging from water purification to water splitting, air filtration, and surgical instrument sterilization, and harvest optical energy to drive chemical reactions. These semiconductors harvest optical energy to drive chemical reactions. With chemical reactions dictated by atomic and molecular interactions at the nanoscale, examining these processes with near-atomic resolution is necessary to understand photochemical processes in depth and to improve materials for next-generation catalysts. The performance and key electronic properties of semiconductors are dictated by the interplay between the surface chemistry and morphology, whose manipulation has inspired experimental and theoretical researchers. This interplay has been clarified by theoretical studies based on atomic-scale modelling with particular attention given to two sets of degreesof-freedom: the atomic positions and chemical configuration. This perspective article presents the major computational challenges and modern methodological strategies toward advancing the field. The ZnWO 4 material was selected as a case study, and the key concepts developed in recent years are discussed to clarify the morphology, i.e., the exposed surfaces of materials, and explain its functional properties or performance. First-principle calculations capture the geometric and electronic effects on the photocatalytic activity in agreement with experimental data. Indeed, important and often surprising structure-function relations have been observed based in depth atomistic modelling on morphological analysis. An overview of past achievements and future directions is provided according to the authors' outlook.

show abstract

Mechanism of Antibacterial Activity via Morphology Change of α-AgVO₃: Theoretical and Experimental Insights

Cited by 60 publications

References 42 publications

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

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

Novel Antimicrobial Titanium Dioxide Nanotubes Obtained through a Combination of Atomic Layer Deposition and Electrospinning Technologies

Reading at exposed surfaces: theoretical insights into photocatalytic activity of ZnWO4

Contact Info

Product

Resources

About

Mechanism of Antibacterial Activity via Morphology Change of α-AgVO3: Theoretical and Experimental Insights

Cited by 60 publications

References 42 publications

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

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

Novel Antimicrobial Titanium Dioxide Nanotubes Obtained through a Combination of Atomic Layer Deposition and Electrospinning Technologies

Reading at exposed surfaces: theoretical insights into photocatalytic activity of ZnWO4

Contact Info

Product

Resources

About

Mechanism of Antibacterial Activity via Morphology Change of α-AgVO₃: Theoretical and Experimental Insights