Ultra-thin silver nanoparticles film prepared via pulsed laser deposition: Synthesis, characterization, and its catalytic activity on reduction of 4-nitrophenol

The interaction of nanoparticles with biomolecules and microorganisms is an expanding field of research. Within this field, an area that has been largely unexplored is the interaction of metal nanoparticles with viruses. In this work, we demonstrate that silver nanoparticles undergo a size-dependent interaction with HIV-1, with nanoparticles exclusively in the range of 1–10 nm attached to the virus. The regular spatial arrangement of the attached nanoparticles, the center-to-center distance between nanoparticles, and the fact that the exposed sulfur-bearing residues of the glycoprotein knobs would be attractive sites for nanoparticle interaction suggest that silver nanoparticles interact with the HIV-1 virus via preferential binding to the gp120 glycoprotein knobs. Due to this interaction, silver nanoparticles inhibit the virus from binding to host cells, as demonstrated in vitro.

Materials of perovskite-type structure have attracted considerable attention for their applications in photocatalysis. In this study, a novel composite of p-type LaFeO3 microsphere coated with n-type nanosized graphitic carbon nitride nanosheets was constructed by the quasi-polymeric calcination method with the aid of electrostatic self-assembly interaction. Results indicate that the LaFeO3/g-C3N4p-n heterostructured photocatalyst obtained, in contrast to the pure constituents, enabled improved visible-light absorption, and more efficient separation and migration of charge carriers via solid p-n heterojunction interfacial effect. Correspondingly, the LaFeO3/g-C3N4 composite allowed for higher visible-light-responsive photocatalytic activity for the degradation of Brilliant Blue, which was 16.9 and 7.8 times that of pristine g-C3N4 and LaFeO3, respectively. The photocatalytic degradation of Brilliant Blue was ascribed to the combined contributions of the photogenerated holes (h+), superoxide radicals (O2-) and hydroxyl radicals (OH). Based on solid p-n heterojunction interfacial interaction, a Z-scheme charge carrier transfer pathway integrated with the dye-sensitization effect is proposed as the underlying mechanism of the photocatalytic reaction process. Therefore, we believe that the perovskite-type LaFeO3/g-C3N4 Z-scheme photcatalyst promotes the development of photocatalysis and holds much promise for environmental remediation.