Facile synthesis of silver sulfide/bismuth sulfide nanocomposites for photocatalytic inactivation of Escherichia coli under solar light irradiation

In this paper, novel uniformly distributed silver sulfide/bismuth sulfide nanocomposites (Ag2S/Bi2S3 NCs) were prepared by using one-step method for the photocatalytic inactivation against Gram-negative bacteria Escherichia coli (E. coli) under solar light irradiation. The results showed that Ag2S/Bi2S3 NCs simultaneously had uniform platelets and coralloid particles with regular shape and perfect dispersion properties and could render the capability of absorbing a broad solar spectrum. The antibacterial tests demonstrated that higher bactericidal rate was obtained with 1.0 mg/mL of Ag2S/Bi2S3 NCs under solar light irradiation during 100 min at 37 °C. It was confirmed by using fluorescence method that hydroxyl radicals generated in the photocatalytic process were the major responsibility for the photoinactivation. This work provides a promising photocatalyst in the bactericidal fields.

► Novel Ag2S/Bi2S3 nanocomposites were prepared by one-step method.
► Ag2S/Bi2S3 nanocomposites could be activated by absorbing a broad solar spectrum.
► Ag2S/Bi2S3 displayed excellent antibacterial activity against Escherichia coli.
► Hydroxyl radicals were confirmed to be the major responsibility for the photoinactivation.