Pure Bi2S3, ZnS, and different ratios of Bi2S3 to ZnS, and ZnS to Bi2S3 have been prepared by hydrothermal method to investigate their efficiency in the adsorption of a toxic cationic methylene blue (MB) dye from synthetic aqueous solutions, and to prove that the heterojunction addition of zinc sulphide to bismuth sulphide and bismuth sulphide to Zinc sulphide with different ratios (1.0, 3.0, 7.0 ...