Synthesis of selenium–silver nanostructures with enhanced antibacterial, photocatalytic and antioxidant activities

The development of a durable and efficient composite material that could perform a long-life antibacterial activity and radical scavenging ability is highly needed. In this paper, selenium nanostructures of different morphologies were synthesized by a wet chemical method under mild experimental setup. Silver nanoparticles were doped on the surface of these nanostructures and successfully characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray, and high-resolution transmission electron microscopy. The potential applications of the designed composite were investigated in multiple disciplines including antibacterial, antioxidant, and photocatalytic activities. The selenium silver (Se–Ag) nanocomposite was employed as an antibacterial agent against a Gram-positive bacterium and a Gram-negative bacterium, and our findings disclosed that the designed composite is an excellent material in inhibiting the challenged bacterial strains. The Se–Ag composite has shown excellent activity with 30-mm inhibition zone at 2 mg/ml concentration, and maintains significant antibacterial efficacy for 72 h, indicating its sustainable performance for a long-life period. Furthermore, Se–Ag nanocomposite also exhibited a significant radical scavenging property against 2,2-diphenyl-1-picrylhydrazyl free radical and an enhanced photocatalytic activity (90–95%) with complete dye decolorization in 70 min. The superior antibacterial activity (zone of inhibition 30 mm), photocatalytic (95%) and antioxidant performance (78%) of the nanocomposite are due to the combined antibacterial (17 mm), photocatalytic (~ 30%) and antioxidant potentials (15%) of the Ag and Se (16 mm, 40%, 25%), respectively.