Methods of synthesizing Bi2S3—;CdS particles in the form of spheres as well as properties of these Bi2S3—;CdS particles are described. Methods of photocatalytic degradation of organic pollutants employing these Bi2S3—;CdS particles and methods of preventing or reducing microbial growth on a surface by applying these Bi2S3—;CdS particles in the form of a solution or an antimicrobial product onto the surface are also specified.