If you are looking for high-quality products, please feel free to contact us and send an inquiry, email: brad@ihpa.net
Zinc sulfide (formula ZnS) is the main zinc compound that occurs naturally, mainly as the mineral sphalerite. In its pure white, dense synthetic compound form it is used as a pigment and is very important in the manufacture of infrared optical windows. It is also doped with different activators to make phosphorescent and electroluminescent materials. It is a wide bandgap semiconductor and an efficient photocatalyst.
In solution, it exists in two crystalline forms with tetrahedral coordination geometry at Zn and S: sphalerite or zinc blende, and wurtzite or polhemusite. This phenomenon is called polymorphism. The sphalerite and wurtzite forms have different chemical properties.
When zinc sulfide is put into aqueous solution, its surface is hydrated immediately. As a result, there is quick increase of hydroxide ions in solution and the pH value jumps rapidly. The stoichiometry of the zinc sulfide surfaces has an important influence on the acid-base behavior and pH buffer capacity of the resulting suspension.
The adsorption of ethyl and octyl sulfates to the surface of the wurtzite forms is slower than that to the sphalerite surfaces, because wurtzite has less hydrogen bonds between its atoms. The stability of wurtzite at higher temperatures is also better than that of the sphalerite.