Aluminum sulfide, Al2S3, is a gray chemical compound with the formula Al2S3. It is moisture sensitive and hydrolyzes to produce gaseous hydrogen sulfide. It is slightly soluble in water and primarily soluble in acid solutions. It can react with sodium or potassium bases to form sodium sulfide, an irritant.
The ionic bond between aluminum and sulfur in aluminum sulfide is based on the transfer of electrons from the metal to the non-metal. Aluminum has three valence electrons and gives up all of them to sulfur, which has six valence electrons. Aluminum sulfide is an ionic compound with the formula Al2S3.
It is a common ingredient in styptic pencils, used for minor cuts and abrasions. It also has many practical applications in the medical industry, such as an ingredient in teeth whiteners and a coagulant for blood samples.
When exposed to water, aluminum sulfide forms aluminum hydroxide and a much diluted sulfuric acid solution. It is an extremely acidic substance, and can therefore be used to lower the pH of soil for plants that are sensitive to it. For example, gardeners often use aluminum sulfide to change the color of hydrangea flowers by altering the soil’s pH.
The worldwide market for aluminum sulfide is driven by its application in the paper & pulp industry and the water treatment process. It is also used in the production of lithium-sulfur solid-state batteries and as a raw material in the preparation of hydrogen sulfide. It is also an important additive in metallurgy, as it improves the corrosion resistance of steel.