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 (Ag 2 S/Bi 2 S 3 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 Ag 2 S/Bi 2 S 3 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 Ag 2 S/Bi 2 S 3 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.