Method of preparing a bismuth sulfide particle containing antibacterial composition

A method of preparing a Bi2S3-CdS particle-containing antibacterial composition, comprising:

• mixing a bismuth(III) salt, a cadmium(II) salt, and an optionally substituted thiourea with a solvent in the presence of polyvinylpyrrolidone to form a reaction mixture;
• heating the reaction mixture in an autoclave at a temperature of 100-300° C. for 2-48 hours thereby forming Bi2S3-CdS particles,
• wherein the Bi2S3-CdS particles are in the form of spheres with an average diameter of 0.3-5 μm, and
• wherein the Bi2S3-CdS particles exhibit a light absorbance of 0.4 to 0.8 at a wavelength of 450 to 800 nm in UV-Vis diffuse reflectance spectroscopy;
• and
• mixing the Bi2S3-CdS particles with a carrier, solvent or adjuvant to form the Bi2S3-CdS particle-containing antibacterial composition,
• wherein the Bi2S3-CdS particles comprise bismuth(III) sulfide and cadmium(II) sulfide, and
• wherein the Bi2S3-CdS particle-containing antibacterial composition exhibits a minimal bactericidal concentration (MBC) of 1.25 to 5 mg/mL.